the significance of bonaire, netherlands antilles, as a breeding

CONTENTS

HISTORICAL BREEDING DISTRIBUTION AND ABUNDANCE OF THE WHITE-CROWNED PIGEON (PATAGIOENAS LEUCOCEPHALA) ON ST. CROIX, US VIRGIN ISLANDS. Douglas B. McNair ………........... 1

GROUND VERSUS ABOVE-GROUND NESTING OF COLUMBIDS ON THE SATELLITE CAYS OF ST. CROIX, US VIRGIN ISLANDS. Douglas B. McNair .................................................................................................. 8

VARIATION AND HYBRIDIZATION IN THE GREEN HERON (BUTORIDES VIRESCENS) AND STRIATED HERON (B. STRIATA) IN TRINIDAD AND TOBAGO, WITH COMMENTS ON SPECIES LIMITS. Floyd E. Hayes ............ 12

THE SIGNIFICANCE OF BONAIRE, NETHERLANDS ANTILLES, AS A BREEDING SITE FOR TERNS AND PLOVERS. Jeffrey V. Wells and Allison Childs Wells ................................................................................. 21

ENDANGERED PIPING PLOVERS (CHARADRIUS MELODUS) OVERWINTERING IN PUERTO RICO. Allen R.

Lewis, Adrianne G. Tossas, José A. Colón, and Beatriz Hernández .......................................................... 27 FIVE NEW SPECIES OF BIRDS FOR ARUBA, WITH NOTES ON OTHER SIGNIFICANT SIGHTINGS. Steven G.

Mlodinow .................................................................................................................................................... 31 ANÁLISIS DE LAS RECUPERACIONES DE EJEMPLARES ANILLADOS DE GARZAS Y COCOS (CICONIIFORMES)

EN EL PERIODO DE 1913 A 1998. Dennis Denis Avila y Hector M. Salvat Torres …………....................... 36 SECOND AND THIRD RECORDS OF WESTERN MARSH-HARRIER (CIRCUS AERUGINOSUS) FOR THE

WESTERN HEMISPHERE IN PUERTO RICO. Christopher L. Merkord, Rafy Rodríguez, and John

Faaborg ...................................................................................................................................................... 42 FIRST RECORD OF THE WESTERN REEF-HERON (EGRETTA GULARIS) FOR ST. VINCENT AND THE

GRENADINES. Michael R. Paice ................................................................................................................. 45 STATUS OF THE AMERICAN OYSTERCATCHER (HAEMATOPUS PALLIATUS) IN ST. VINCENT AND THE

GRENADINES. Floyd E. Hayes, Michael R. Paice, Tony Blunden, P. William Smith, Susan A. Smith,

Graham White, and Martin D. Frost .......................................................................................................... 48 HISPANIOLAN LIZARD-CUCKOO (COCCYZUS LONGIROSTRIS) TETHERED BY COMMON GREEN SNAKE

(UROMACER CATESBYI). Thomas H. White, Jr. ............................................................................................ 52 FIRST RECORD OF AUDUBON’S WARBLER (DENDROICA CORONATA AUDUBONI) IN JAMAICA. Gary R.

Graves ........................................................................................................................................................ 54 GREATER ANTILLEAN GRACKLE (QUISCALUS NIGER) PREYS ON ANOLIS GRAHAMI. Gary R. Graves ............ 56 PRIMER REGISTRO SOBRE LA REPRODUCCIÓN DEL OSTRERO AMERICANO (HAEMATOPUS PALLIATUS) EN

CUBA. Ernesto Hernández Pérez ............................................................................................................... 59

2006 (ISSN 1544-4953)

Vol. 19, No. 1

SOCIETY FOR THE CONSERVATION AND STUDY OF CARIBBEAN BIRDS SOCIEDAD PARA LA CONSERVACIÓN Y ESTUDIO DE LAS AVES CARIBEÑAS

ASSOCIATION POUR LA CONSERVATION ET L’ ETUDE DES OISEAUX DE LA CARAÏBE

Formerly EL PITIRRE

THE JOURNAL OF CARIBBEAN ORNITHOLOGY


THE JOURNAL OF THE SOCIETY FOR THE CONSERVATION AND STUDY OF CARIBBEAN BIRDS LA REVISTA DE LA SOCIEDAD PARA LA CONSERVACIÓN Y ESTUDIO DE LAS AVES CARIBEÑAS

LE JOURNAL DE L’ ASSOCIATION POUR LA CONSERVATION ET L’ ETUDE DES OISEAUX DE LA CARAÏBE Editor in Chief FLOYD E. HAYES, Department of Biology, Pacific Union College, 1 Angwin Ave., Angwin, CA 94508, USA;

telephone: 707-965-6401; fax: 707-965-7577; e-mail: [email protected] Associate Editors WAYNE ARENDT, P. O. Box 534, Luquillo PR 00773-0534, USA; e-mail: [email protected]. P. A. BUCKLEY, 211 Meadowtree Farm Road, Saunderstown, RI 02874, USA; e-mail: [email protected] DENNIS DENIS AVILA, Facultad de Biología, Universidad de la Habana, Calle 25 e/J e I, Vedado, Ciudad

Habana, Cuba; e-mail: [email protected]

ANDREW DOBSON, Warwick Academy, 117 Middle Rd., Warwick PG01, Bermuda; e-mail: adobson@war-

wickacad.bm PHILIPPE FELDMANN, Cirad, TA 179/04, 34398 Montpellier Cedex 5, France; e-mail: [email protected] RUUD VAN HALEWIJN, 14 Adelaarhof, Utrecht, 3514 TZ, The Netherlands; e-mail: [email protected]

SUSAN KOENIG, Windsor Research Centre, Sherwood Content P.O., Trelawny, Jamaica; e-mail: wind-

[email protected] OLIVER KOMAR, SalvaNATURA, Colonia Flor Blanca, 33 Ave. Sur #640, San Salvador, El Salvador; e-

mail: [email protected] LOURDES MUGICA VALDES, Facultad de Biología, Universidad de la Habana, Calle 25 entre J e I, Vedado,

Ciudad Habana, Cuba; e-mail: [email protected] ANTONIO RODRÍGUEZ SUÁREZ, Facultad de Biología, Universidad de la Habana, Calle 25 entre J e I, Ve-

dado, Ciudad Habana, Cuba; e-mail: [email protected] JOSEPH WUNDERLE, International Institute of Tropical Forestry, USDA Forest Service, P.O. Box 507,

Palmer, Puerto Rico 00721; e-mail: [email protected] Book Review Editor STEVEN C. LATTA, PRBO Conservation Science, 4990 Shoreline Highway, Stinson Beach, CA 94970, USA;

e-mail: [email protected] Editorial Assistants MELISSA CHROWL, BRETT HAYES, AND CHRISTIAN VON POHLE; Department of Biology, Pacific Union Col-

lege, 1 Angwin Ave., Angwin, CA 94508, USA; e-mail: [email protected] © Society for the Conservation and Study of Caribbean Birds, 2006 The Society for Conservation and Study of Caribbean Birds (SCSCB) is a non-profit organization under sec-tion 501(c)3 of the United States Internal Revenue Code. All contributions are fully tax-deductible to the ex-tent allowed by U. S. law. We welcome private support from individuals, corporations, and foundations. Out-right gifts and pledges may be made by contacting the SCSCB Treasurer at [email protected] or by writing to PO Box 863208, Ridgewood, NY 11386, USA. Typeset in Microsoft Office Publisher by Floyd E. Hayes. Printed by Preferred Images, Pacific Union College, Angwin, CA, USA. ISSN 1544-4953

HISTORICAL BREEDING DISTRIBUTION AND ABUNDANCE OF THE WHITE-CROWNED PIGEON (PATAGIOENAS LEUCOCEPHALA)

ON ST. CROIX, US VIRGIN ISLANDS

DOUGLAS B. MCNAIR

Division of Fish and Wildlife, Department of Planning and Natural Resources, 45 Mars Hill, Frederiksted,

United States Virgin Islands 00840, USA; current address: Sapphos Environmental, Inc., 133 Martin Alley, Pasadena,

CA 91105, USA; e-mail: [email protected]

Abstract: I critically assessed historical data (before 2002) on the breeding distribution and abundance of the White-crowned Pigeon (Patagioenas leucocephala) on St. Croix, US Virgin Islands, since the first confirmed breed-ing record in 1858. White-crowned Pigeons have formed moderate to large colonies at three colony sites, two cays (Green Cay, Ruth Island) and a mangrove wetland (the former Krause Lagoon; destroyed in 1962), although only one of these three colony sites has ever been documented to be a large active colony at a given time. The largest certain documented site was at the former Krause Lagoon, where up to 600 birds nested in the 1950s, although the colony at Green Cay in the 1910s and 1920s may have been much larger. Historical data for the White-crowned Pigeon on St. Croix are generally sparse because of insufficient observer effort, and the difficulty of obtaining reli-able population estimates is further compounded because of poaching of adults and squabs at the largest colony sites, most recently at Ruth Island, a man-made cay located just south of the former Krause Lagoon. Key words: abundance, colony site, distribution, Green Cay, Krause Lagoon, Patagioenas leucocephala, poaching, Ruth Island, St. Croix, US Virgin Islands, White-crowned Pigeon Resumen: DISTRIBUCIÓN DE HISTÓRICA DE CRÍA Y ABUNDANCIA DE LA PALOMA CABECIBLANCA (PATAGIOENAS

LEUCOCEPHALA) EN ST. CROIX, ISLAS VÍRGENES DE EEUU. Se realizó una revisión crítica de los datos históricos (anteriores al 2002) acerca de la distribución de cría y la abundancia de la Paloma Cabeciblanca (Patagioenas leuco-

cephala) en St. Croix, Islas Vírgenes de EEUU, desde el primer registro confirmado de su cría en 1858. La Paloma Cabeciblanca ha formado colonias de moderadas a grandes en tres localidades, dos cayos (Green Cay, Ruth Island) y un manglar (la antigua Laguna Krause; destruida en 1962). Solo una localidad ha sido documentada actualmente como una gran colonia activa. El mayor sitio documentado fue el de la antigua Laguna Krause, donde hasta 600 aves anidaron en la década de los años 50, aunque la colonia en Green Cay, alrededor de 1910 y 1920, podría haber sido mucho mayor. Los datos históricos para la Paloma Cabeciblanca en St. Croix son generamente escasos a causa de un insuficiente esfuerzo de observación, y la dificultad de obtener estimados poblacionales confiables se ha derivado de la caza furtiva de adultos y pichones en la mayor colonia, más recientemente en Ruth Island, un cayo artificial locali-zado justo al sur de la anterior Laguna Krause. Palabras clave: abundancia, caza furtiva, colonias, distribución, Green Cay, Islas Vírgenes de EEUU, Laguna Krause, Paloma Cabeciblanca, Patagioenas leucocephala, Ruth Island, St. Croix Résumé : DISTRIBUTION HISTORIQUE ET ABONDANCE DU PIGEON A COURONNE BLANCHE (PATAGIOENAS LEUCO-

CEPHALA) À ST. CROIX, ILES VIERGES AMÉRICAINES. Une analyse critique des données historiques a été faite sur la distribution des nicheurs et l’abondance du Pigeon à couronne blanche (Patagioenas leucocephala) à St. Croix, Iles Vierges Américaines, depuis la première observation de nidification confirmée en 1858 jusqu’en 2001. Cette espèce avait constitué plusieurs colonies de taille moyenne à grande sur 3 sites, 2 îlots (Green Cay, Ruth Island) et un marais de mangrove (l’ancien Krause Lagoon, détruit en 1962). Cependant, seul un de ces 3 sites a toujours été con-sidéré comme étant une colonie active et importante. Le site le plus important connu était Krause Lagoon, où jusqu’à 600 oiseaux nichaient dans les années 1950, bien que la colonie de Green Cay ait pu être encore plus important dans les années 1910 et 1920. Les données historiques du Pigeon à couronne blanche sont globalement rares à St. Croix en raison d’une pression d’observation insuffisante et la difficulté d’obtention d’estimations fiables des populations est aggravée par le braconnage d’adultes et de poussins sur les sites des colonies les plus importantes, et plus récem-ment à Ruth Island, un ilot artificiel situé juste au sud de Krause Lagoon. Mots-clés : abondance, braconnage, colonies, distribution, Green Cay, Iles Vierges Américaines, Krause Lagoon, Patagioenas leucocephala, Pigeon à couronne blanche, Ruth Island, St. Croix

THE ABUNDANCE OF THE territorially endangered White-crowned Pigeon (Patagioenas leucocephala) breeding population at Krause Lagoon, St. Croix, United States Virgin Islands, before the construction

of a large industrial complex in 1962 destroyed it, has never been documented and critically assessed other than by Dammann (1977) and Arendt et al. (1979), whose examination of Seaman’s quarterly

J. Carib. Ornithol. 19:1-7, 2006

Journal of Caribbean Ornithology 19(1), 2006 1

2 Journal of Caribbean Ornithology 19(1), 2006

MCNAIR — PATAGIOENAS LEUCOCEPHALA IN ST. CROIX, US VIRGIN ISLANDS

federal-aid reports (funded under the Pittman-Robertson Act of 1937) was incomplete. In this note I examine published and unpublished materials, much of the latter from federal-aid reports including all of Seaman’s, to obtain estimates of the historical breeding population of the White-crowned Pigeon on St. Croix.

METHODS Counts or estimates of the number of birds and

nests at each historical breeding site were initially taken at face value from the original source. Esti-mates of the number of birds by Seaman at Krause Lagoon (260 ha) were usually extrapolated from nest counts over a portion of this area. Where war-ranted, I reinterpret the fragmented and incomplete data and conclusions of Beatty, Seaman, Knowles, and other individuals about the size of breeding populations at various historical sites. These data include the most recent site at Ruth Island, just south of the former Krause Lagoon, which was cre-ated by placing dredged spoil taken from channels excavated for the industrial complex on a nearshore bar (Long Reef). Subsequent to vegetative coloniza-tion and succession, Ruth Island became the main breeding site for White-crowned Pigeons on St. Croix (Knowles 1994, 1995, 1997). However, data on the abundance of the breeding population at Ruth Island, where this pigeon breeds semi-colonially in dense aggregations (and formerly on Green Cay; Beatty 1930), have also never been critically exam-ined. These historical data form the basis of our knowledge of breeding White-crowned Pigeons on St. Croix prior to initiation of new surveys in 2002 (McNair unpubl. data).

RESULTS UNKNOWN LOCALITY

The earliest record of breeding White-crowned Pigeons on St. Croix was a juvenile “which could not have left the nest many days” (University Mu-seum of Zoology, Cambridge 17/col/8/w/3) shot on 28 July 1858 by Newton and Newton (1859). GREEN CAY Beatty (1944) stated this cay was occupied “by a colony of 10,000 breeding birds [White-crowned Pigeons] from 1916 to 1920” but they have not nested there since that period. He also stated earlier (Beatty 1930) that White-crowned Pigeons nested in “countless numbers” on Green Cay in the early 1920s, when the northern part of this cay had intact

heavy woodland (unlike today, it is now low scrub; Woodbury and Vivaldi 1982). The only documented breeding evidence was two eggs taken from a nest on 21 June 1921 (Beatty 1930). Seaman (1973, 1993) also observed breeding birds at Green Cay during the 1920s, but provides no numbers and it is impossible to separate information on White-crowned Pigeons in his accounts from Zenaida Doves (Zenaida aurita). Dammann (1977) stated birds at Green Cay had been shot out since 1946, but presented no data. In the 1980s, Fred W. Sladen (pers. comm.) observed small numbers of White-crowned Pigeons on Green Cay during the main breeding period (May-July), although he found no nests. SOUTHGATE POND Seaman (1993) suggested that White-crowned Pigeons were formerly restricted to nesting on St. Croix proper during the 1920s at Southgate Pond, just across from Green Cay (350 m), but no docu-mented evidence exists. Sladen (in Scott and Car-bonell 1986) stated birds bred at Southgate Pond in the 1980s, but did not discover nests. Breeding habitat would have been in mangrove wetlands and littoral woodland on the beach berm. KRAUSE LAGOON Harry A. Beatty was the first individual to docu-ment nesting over many years (11 June 1934, 30 May 1939, 3 May 1941, 4 May 1941, and 15 June 1944) when he collected five sets of two eggs (Western Foundation of Vertebrate Zoology 17348, WFVZ 17347, San Bernardino County Museum 2P30, United States National Museum B46833; and Delaware Museum of Natural History 471, respec-tively). In 1942, Beatty (1943) stated a “large col-ony” was nesting in the mangroves on 21 July. From 300-600 birds nested at Krause Lagoon in 1944 and through the 1950s (Table 1), usually based on extrapolated estimates from counts of nests that ranged as high as 170 per year. George A. Seaman banded 1,271 squabs from 1950 to 1960 (Table 1). The estimated number of adult birds and number of banded squabs per year (n = 6) were positively cor-related (Spearman’s rank correlation, rs = 0.84, P = 0.04), even though the breeding population gener-ally declined during the 1950s, but by no more than half its maximum number in 1950 (contra Dam-mann 1977). Dammann and Nellis (1992) stated that Krause Lagoon was formerly “the home of thousands” of White-crowned Pigeons, but I cannot find any substantiation for this statement.


KRAUSE LAGOON REMNANT Dammann (1977) stated that a “few” birds nested in dead mangroves at Krause Lagoon Remnant, but White-crowned Pigeons do not nest in dead man-groves (McNair pers. obs.). Ten birds were at Krause Lagoon Remnant during June 1982 (Norton 1982) and Sladen (in Scott and Carbonell 1986) discovered fewer than ten breeding pairs there in the 1980s. SALT RIVER ESTUARY Seaman (1993) stated that “hundreds” of White-crowned Pigeons roosted at Salt River Estuary (actually, in Sugar Bay) in the mid-1930s. Accord-ing to Dammann (1977), the birds had been shot out since 1946. Birds still roosted there in 1950, but Seaman (1950a) did not mention any numbers. Also in 1950, Seaman (1950a, b, 1951a) reported that “a small and negligible colony” nested there, perhaps based on second-hand information. Seaman (1954a)

stated that by 1954 White-crowned Pigeons no longer nested at Sugar Bay. Lamb (1957) stated that Salt River Bay was a former breeding site, appar-ently based on information provided by Seaman. Sladen (in Scott and Carbonell 1986) stated birds nested at Sugar Bay in the 1980s, but did not dis-cover any in mangrove wetlands where he implied they occurred. Wauer (1990) presumed White-crowned Pigeons nested in littoral woodland just above Sugar Bay, not in mangroves, but provided no documentation. RUTH ISLAND The first year birds began nesting at Ruth Island, a dredge spoil island created in the early 1960s, is unknown, although they were established by 1980 when Yntema and Sladen (1987) saw an adult sit-ting on a nest, brooding young. The pigeons breed at Ruth Island in littoral woodland and scrub as well as mangrove wetlands (Yntema and Sladen 1987).

Table 1. Estimated number of adult birds, minimum number of nests, and number of banded young of the White-crowned Pigeon documented at Krause Lagoon from 1944 to 1961 on St. Croix, U. S. Virgin Islands.

Year

Number of Adults

Number of Nests

Number of Visits

Range of Visits Number Bandeda

Reference(s)

1944 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961

500 “half its for-

mer size” 600

500e

45 350

300

“few hun-dred”

500

170b

60+ 54+; 19

55+ 83+

83+

U

30+

5 Uc

U U

U 4+

3

U

5

Jun May - Jun

12 Jun - Aug

21 Jun - 3 Aug May - Jul Jun - Aug

<18 May - 24 Jul; 4 Nov

28 Apr - 28 Jul 29 May - 14 Aug

21 Jun - 26 Jul

late May - 9 Jul 13 May - Sep

25 May - 25 Jul

174 122 97 180 150

110 38

54

103 243

Beatty 1944 Seaman 1949 Seaman 1950a, b Seaman 1951b BBLd Seaman 1953, 1954b Seaman 1954a, b Seaman 1955 Seaman 1956a, b, Lamb 1957 Seaman 1957b Seaman 1958 Seaman 1959a, b Seaman 1960 Seaman 1961

adata supplied by the Bird Banding Laboratory, Patuxent Wildlife Research Center, U. S. Geological Survey bsome of the same nests may have been sampled on different days, although White-crowned Pigeons fre-quently reuse the same nest cunknown ddata on range of visits also supplied by the Bird Banding Laboratory eabout two-thirds of the birds were breeding, according to Seaman (1954a)



Knowles (1994, 1995) reported that 200-300 pairs of White-crowned Pigeons nested at Ruth Island in 1993. After he established plots beginning in 1994, Knowles (1994, 1995, 1997) estimated that a mini-mum number of 633, 961, and 899 pairs nested at Ruth Island in 1995, 1996, and 1997, respectively. OTHER BREEDING SITES Sladen (in Scott and Carbonell 1986; Sladen pers. comm.) discovered from 1-10 breeding pairs at seven other sites in the 1980s, at Altona Lagoon, the Buccaneer Hotel, Coakley Bay Salt Pond, Great Pond, Manning Bay Lagoon, Sandy Point National Wildlife Refuge (NWR), and the University of Vir-gin Island (UVI) Wetlands. In addition to birds nest-ing on Ruth Island, Sladen confirmed breeding (nests found, with eggs or young) on at least four of these seven sites (Great Pond, Manning Bay La-goon, Sandy Point NWR, UVI Wetlands). Breeding pairs at all sites were located in mangrove wetlands including Great Pond, except for additional birds at Great Pond in littoral woodland on the beach berm and at the Buccaneer Hotel where they only nested in littoral woodland.

DISCUSSION Historical data on the White-crowned Pigeon breeding population on St. Croix are sparse, other than those for the former Krause Lagoon during the 1950s and Ruth Island during the mid-1990s. Birds were formerly concentrated at Green Cay, then Krause Lagoon, where documented breeding popu-lations did not overlap. It is impossible to recon-struct a plausible population estimate for birds on Green Cay (Beatty’s claim of 877 pairs/ha, if it had been confirmed, would have been the densest breed-ing aggregation ever documented; Bancroft and Bowman 2001). Apparently plausible documented population estimates are available for Krause La-goon, most from the 1950s, when the maximum annual population estimate for this multi-brooded pigeon was 600 birds in 1950 (contra Dammann 1977). Following destruction of the former Krause La-goon (Norton and Seaman 1985), Ruth Island be-came the apparent primary breeding site on St. Croix by the 1990s, although it is unknown when birds first began breeding there except that it was sometime between 1962 and 1980. The proximity of uninhabited Ruth Island to the former Krause La-goon probably facilitated colonization. Knowles overlooked many other breeding sites on St. Croix discovered by Sladen in the 1980s, that were un-

doubtedly active in the 1990s regardless of any ef-fects of heightened hurricane activity on habitat since 1989 (e.g., Wauer and Wunderle 1992, Wiley and Wunderle 1993). These populations were probably small, suggested by the size of recent (2002-2003) breeding populations at all of these sites except for one for which there has been a re-cent, obvious increase because of favorable habitat change (McNair unpubl. data). The larger size of the breeding population of White-crowned Pigeons at Ruth Island, however, must not have been nearly as large as Knowles had estimated. His original data were not documented or presented in a form that can be extracted to reana-lyze the data, so the size of the breeding population is unknown; it probably did not exceed 150-200 pairs. Knowles’s estimates at Ruth Island were ap-proximately 2-3 times greater than the largest esti-mate of the former breeding population at Krause Lagoon. This is unlikely, even though White-crowned Pigeon nests at Ruth Island can be closely packed in littoral woodland (as they may have been at Green Cay), whereas at Krause Lagoon they were usually spaced widely apart in red mangroves but over a much larger area (260 ha compared to 7.1 ha). Knowles attributed the breeding population crash at Ruth Island in 1994 and low nest success during the other 3 yr to predation, which he rarely observed or documented. However, poaching of squabs occurred regularly at Krause Lagoon, where Seaman on a single visit noted that up to 25% of his marked nests poached, and may better explain Knowles’s data. Poaching by squab poachers was diffused here because nests were dispersed, the habitat was tiresome to traverse, and the large size of Krause Lagoon prevented breeding failure from occurring from poaching alone. The smaller size of mangrove wetlands at Salt River Bay may have allowed poachers (of squabs and adults) to wipe out the breeding colony. Poaching of squabs is an illegal practice that con-tinues today at Ruth Island, where nearly complete breeding failure probably occurred in 2002 because the aggregated, accessible nests on this small island facilitate poaching (McNair unpubl. data). Negligi-ble poaching of adults and juveniles otherwise oc-curs island-wide, but this was a common practice during Seaman’s day even during the breeding sea-son which sometimes coincided with the opening of the hunting season on St. Croix (e.g., 16 August in 1956; 1 July in 1960; Seaman 1957a, 1960; Norton and Seaman 1985). Surviving adults at Green Cay, then later at Krause Lagoon, probably dispersed to



breed at other sites on St. Croix (and perhaps other islands), although this was not documented, as they continued to be reduced by hunting pressure (including poaching), and later, at Krause Lagoon by habitat destruction (Dammann 1977, Norton and Seaman 1985; cf., northern US Virgin Islands: Nichols 1943; British Virgin Islands: Mirecki et al. 1977; Puerto Rico: Wiley 1977, 1979, Arendt et al. 1979). Hunting pressure may have led to cessation of breeding at Salt River Estuary (= Sugar Bay), assuming breeding occurred, although the apparent population size was small, at least by 1950. The main reason for continued hunting pressure was to kill larger numbers of roosting birds in late summer and early autumn, especially in the mature man-grove forest. The effects of hunting pressure and poaching of squabs on numbers of White-crowned Pigeons, in addition to insufficient documentation or lack of substantiation of claims over many years, makes it difficult to make plausible population esti-mates at most historical breeding sites. It is also uncertain how many breeding sites were active on St. Croix and how important they were before the elimination of breeding birds from Green Cay by 1930 and before the destruction of Krause Lagoon and after the creation of Ruth Island during the early 1960s. It is perhaps notable, however, that no more than one historical breeding site of moderate or ma-jor importance has ever been documented to be ac-tive at a given time on St. Croix. Insufficient observer effort since Seaman’s day, especially on St. Croix proper, contributed to uncer-tainty about historical breeding populations. Enig-matically, Seaman (1993) never saw a White-crowned Pigeon in the western end of St. Croix (including Krause Lagoon) during his childhood, but only saw his first birds at Southgate Pond and Green Cay during the early 1920s because Beatty introduced him to the species there. Much later, Seaman (1993) considered White-crowned Pigeons summer residents of mangrove swamps, yet appar-ently never searched for the species in littoral wood-land (other than Green Cay). Nellis et al. (1984) failed to find any breeding sites of the White-crowned Pigeon on St. Croix during the mid-to-late 1970s. Breeding sites in littoral woodland were documented on St. Croix proper (and Ruth Island and Green Cay) in the 1980s when one individual (F. W. Sladen) finally looked for them in this habi-tat. Insufficient observer effort also extended to mangrove wetlands, even though this breeding habi-tat is generally preferred by pigeons compared to littoral woodland (except on islands) because anti-

predator adaptations include selection of relatively remote sites and placement of nests directly over water (Wiley 1979, Campbell 1991).

ACKNOWLEDGMENTS I thank F. W. Sladen for contributing data, K.

Carter (Biological Sciences Division, San Bernar-dino County Museum), R. Corado (Collections Manager, Western Foundation of Vertebrate Zool-ogy), J. P. Dean (Collections Manager, Division of Birds, Department of Systematic Biology, Smith-sonian Institution), G. K. Hess (Collections Man-ager, Department of Birds, Delaware Museum of Natural History), and R. Symonds (Collections Manager, University Museum of Zoology, Cam-bridge) for providing information from their orni-thological collections, K. Klimkiewicz of the Bird Banding Laboratory, Patuxent Wildlife Research Center, United States Geological Survey for provid-ing copies of Seaman’s banding data from Krause Lagoon, C. D. Lombard, F. F. Rivera-Milan, and J. W. Wiley for reviewing a penultimate draft of this manuscript, and W. J. Arendt and one anonymous individual for their reviews of the submitted manu-script. I also thank the USFWS for financial support (Federal Aid Program, Pittman-Robertson Colum-bids Project, W12, Study 1) and Christine Willis for her support. Copies of unpublished manuscripts listed below are available from the author.

LITERATURE CITED ARENDT, W. J., T. A. VARGAS MORA, AND J. W.

WILEY. 1979. White-crowned Pigeon: status rangewide and in the Dominican Republic. Pro-ceedings of the Annual Conference of the South-eastern Association of Fish and Wildlife Agencies 33:111-122.

BANCROFT, G. T., AND R. BOWMAN. 2001. White-crowned Pigeon (Columba leucocephala). In The birds of North America, no. 596 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.

BEATTY, H. A. 1930. Birds of St. Croix. Journal of the Department of Agriculture of Puerto Rico 14: 135-150.

BEATTY, H. A. 1943. Records and notes from St. Croix, Virgin Islands. Auk 60:110-111.

BEATTY, H. A. 1944. Virgin Islands wildlife re-search and restoration project. Pittman-Robertson Quarterly 4:171-173.

CAMPBELL, E. W. 1991. The effect of introduced roof rats on bird diversity of Antillean cays. Jour-nal of Field Ornithology 62:343-348.



DAMMANN, A. E. 1977. The White-crowned Pigeon in the U.S. Virgin Islands, with notes from the Lesser Antilles. Pp. 23-24 in Proceedings of the International White-crowned Pigeon Conference. Bahamas National Trust, Nassau, Bahamas.

DAMMANN, A. E., AND D. W. NELLIS. 1992. A natural history atlas to the cays of the U.S. Virgin Islands. Pineapple Press, Inc., Sarasota, FL.

KNOWLES, W. C. 1994. Nesting White-crowned Pigeons. Annual report, Pittman-Robertson study 10, Division of Fish and Wildlife, St. Croix, USVI.

KNOWLES, W. C. 1995. Nesting White-crowned Pigeons. Annual report, Pittman-Robertson study 10, Division of Fish and Wildlife, St. Croix, USVI.

KNOWLES, W. C. 1997. Determination of breeding characteristics of the White-crowned Pigeon (Columba leucocephala): breeding population size, nesting seasonality, number and success on St. Croix, U. S. Virgin Islands. Final report, Pittman-Robertson grant W10-1, Division of Fish and Wildlife, St. Croix, USVI.

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crowned Pigeon in Puerto Rico. Pages 11-16 in Proceedings of the International White-crowned Pigeon Conference. Bahamas National Trust, Nassau, Bahamas.

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YNTEMA, J. A., AND F. W. SLADEN. 1987. Ruth Island survey. Final report, endangered species project ES-1, Study IIB, Job IIB-1. Division of Fish and Wildlife, U. S. Virgin Islands.



GROUND VERSUS ABOVE-GROUND NESTING OF COLUMBIDS ON THE SATELLITE CAYS OF ST. CROIX, US VIRGIN ISLANDS

DOUGLAS B. MCNAIR1 AND CLAUDIA D. LOMBARD2

1Division of Fish and Wildlife, Department of Planning and Natural Resources, 45 Mars Hill, Frederiksted, United States

Virgin Islands 00840, USA; current address: Sapphos Environmental, Inc., 133 Martin Alley, Pasadena, California 91105,

USA; e-mail: [email protected]; 2United States Fish and Wildlife Service, Federal Building, 3013

Estate Golden Rock, Christiansted, United States Virgin Islands 00820-4355, USA

Abstract: We examined the incidence of ground versus above-ground nesting of columbids on four nearshore cays off St. Croix, US Virgin Islands. Roof rats (Rattus rattus) occurred on two cays (Protestant Cay, Ruth Island), whereas rats were absent from the two other cays (Buck Island, Green Cay) in 2002-2003. We discovered 6 ground nests (2.1%) of three columbids out of 288 nests of five columbids, including the first documented record of ground nesting by the Scaly-naped Pigeon (Patagioenas squamosa). The proportion of ground nests on cays with or without rats was similar (1.5% versus 3.4%). Despite flexible nest-site placement of ground and above-ground nests of columbids on inhabited and uninhabited cays off St. Croix, the low number and restriction of ground nests to early successional habitats suggest that columbids may prefer breeding above-ground when suitable nest-sites are avail-able in more mature habitats regardless of the presence or absence of rats. Key words: above-ground nests, cays, columbids, ground nests, Patagioenas squamosa, Rattus rattus, roof rat, Scaly-naped Pigeon, St. Croix, US Virgin Islands Resumen: NIDIFICACIÓN EN EL SUELO VS SOBRE EL SUELO DE COLÚMBIDOS EN LOS CAYOS SATELLITE DE ST. CROIX, ISLAS VÍRGENES DE EEUU. Se examinó la incidencia de nidificación en el suelo y sobre el suelo de colúmbi-dos en cuatro cayos adyacentes a St. Croix, Islas Vírgenes de EEUU. Las ratas (Rattus rattus) aparecieron en dos de los cayos (Protestant Cay, Ruth Island), mientras que estuvieron ausentes de otros dos cayos (Buck Island, Green Cay) en 2002-2003. Se descubrieron seis nidos en el suelo (2.1%) de tres columbidos, de los 288 nidos de cinco columbidos, incluyendo el primer registro documentado de nidificación en el suelo de la Torcaza Cuellimorada (Patagioenas squamosa). Las proporciones de nidos en el suelo entre los cayos con y sin ratas fue similar (1.5 % versus 3.4 %). A pesar de la flexibilidad en la selección de sitios de nidificación en el suelo o sobre este, de los columbidos en cayos habitados o deshabitados adyactentes a St. Croix, la pequeña cantidad y la restricción de los nidos en el suelo a hábitats sucesionales tempranos sugieren que los columbidos pueden preferir nidificar en lugares altos cuando existen sitios asequibles en hábitats maduros, independientemente de la presencia o no de ratas. Palabras clave: nidos sobre el suelo, cayos, columbidos, Islas Vírgenes de EEUU, nidos en el suelo, Patagioenas

squamosa, Rattus rattus, ratas, Torcaza Cuellimorada, St. Croix Résumé : NIDIFICATION AU SOL COMPAREE A NIDIFICATION AU-DESSUS DU SOL DES COLOMBIDES SUR LES ILETS SATELLITES DE ST. CROIX, ILES VIERGES AMERICAINES. Nous avons comparés la nidification au sol par rapport à la nidification au dessus du sol des colombidés sur 4 ilots de St. Croix, Iles Vierges Américaines. Le Rat noir (Rattus

rattus) est présent sur 2 ilots (Protestant Cay, Ruth Island), alors qu’il était absent des deux autres (Buck Island, Green Cay) en 2002-2003. 6 nids (2,1%) de 3 espèces de colombidés sur les 288 répertoriés de 5 espèces, ont été découverts au sol, dont la première observation confirmée de nidification au sol du Pigeon à couronne blanche (Patagioenas squamosa). La proportion de nids au sol était la même sur les ilots avec ou sans rat (1,5% vs. 3,4%). En dépit de la localisation souple du choix des sites de nidification, au sol ou non, des colombidés sur les ilots habi-tés ou non de St. Croix, le nombre réduit et la localisation des nids au sol aux premiers stades de la succession des habitats, suggère que les colombidés préfèrent nicher au dessus du sol quand des sites adéquats sont disponibles dans des habitats plus évolués, qu’il y ait ou non présence de rats. Mots-clés : nids au dessus du sol, ilots, columbidés, nids terrestres, Patagioenas squamosa, Rattus rattus, Pigeon à couronne blanche, St. Croix, Iles Vierges Américaines

GROUND NESTING by some columbids, especially the Zenaida Dove (Zenaida aurita), may be frequent on cays in the Culebra Archipelago of Puerto Rico and the northern United States Virgin Islands where nest density is greater than on the main islands (Nellis et al. 1984, Burger et al. 1989, 1991, Rivera-Milan and Schaffner 2002). The cays where these

studies were conducted are dominated by rock and grassland-scrub vegetation ≤1 m tall (Dammann and Nellis 1992, Rivera-Milan and Schaffner 2002). Though trees and other woody vegetation were available on some cays, most Zenaida Doves nested on the ground, on flat rocks, in rock crevices, under rock boulders, and on soil completely or partially



covered by vegetation. Ground nests, however, had generally lower success than nests above-ground and overall reproductive success on these cays was low (22-26%), despite the absence of exotic mam-malian predators.

The small Indian mongoose (Herpestes javani-

cus) and roof rat (Rattus rattus) are major predators on nests of landbirds on some cays off Puerto Rico and the U.S. Virgin Islands where these predators occur (Nellis et al. 1984, Campbell 1991, Rivera-Milan and Schaffner 2002). Land crabs (Gecarcinus

ruricola) were the main predator on Zenaida Dove nests (eggs and nestlings) on cays off St. Thomas, where mammalian predators were absent (Nellis et

al. 1984). Despite heavy predation by crabs on small islands without mammalian predators (Nellis et al. 1984, Burger et al. 1991, Rivera-Milan and Schaffner 2002), tree-nesting by some columbids (including Zenaida Doves), if sites are available, generally predominates on small islands with rats and ground nesting on small islands without rats (and other mammalian predators).

Off St. Croix, three of the four cays have always been mongoose-free and the mongoose was suc-cessfully eradicated from Buck Island by the 1990s. Roof rats formerly occurred on all four cays. They were recently eradicated from Green Cay (68 rats removed by live-trapping from June 2000 to Febru-ary 2001; C. D. Lombard unpubl. data) and Buck Island (Witmer et al. 2002), although rats have recolonized Green Cay since 2005 (Lombard pers. obs.) but were absent when this study was con-ducted in 2002-2003. Rats are present but appar-ently are rather scarce on Protestant Cay and Ruth Island (McNair pers. obs.). Pre- and post-removal effects of exotic mammals on columbid nests on the two cays off St. Croix without rats cannot be com-pared because of the absence of pre-removal stud-ies. Nonetheless, columbid nest placement (ground versus above-ground) on cays without rats can be compared to the two cays with rats and results therein can be compared to published studies. The number of ground nests covered by vegetation or under boulders and at other sites may increase in response to the removal of rats (Atkinson 1985, Wiley 1991, Rivera-Milan and Schaffner 2002). Green Cay and Buck Island were free of rats in 2002-2003, when breeding may have shifted from above-ground to ground nests even though repro-ductive success of above-ground nests on large is-lands such as Puerto Rico with high densities of avian and mammalian predators is generally higher than in ground nests on small cays (Wiley 1991,

Rivera-Milan and Schaffner 2002). In this note, we present data on columbid nest-site placement from 2002 and 2003 on four cays off of St. Croix and assess its consistency with the expectation that ground nests should be fairly numerous or at least increase on cays without rats.

STUDY AREA AND METHODS

In the course of several ongoing studies on Green Cay and the three other nearshore cays off St. Croix, we opportunistically obtained information on ground and above-ground nests (trees, shrubs, cacti) of five species of columbids (52 visits in 2002 and 2003). Ground nests as defined herein exclude nests placed in crevices of rock walls or on rock ledges above the ground but include nests placed on the ground among boulders. Vegetative descriptions for Buck Island, Green Cay, and Ruth Island, and vege-tative characteristics for Protestant Cay are avail-able (Woodbury and Little 1976, Woodbury and Vivaldi 1982, Yntema and Sladen 1987, McNair 2003). Briefly, all four cays have extensive or fairly extensive areas of open xeric forest, dry thorn-woodland, or highly modified littoral woodland with exotic vegetation (Protestant Cay) except for man-made Ruth Island, where woodland is more limited in extent and the coral rubble is lightly vege-tated. Small areas of mangrove wetland occur on Ruth Island and Buck Island. Grassland-scrub vege-tation is more limited than woodland on all four cays but is fairly extensive on Green Cay, especially the northern half. Seabird colonies on these cays are absent or limited to low numbers of one or two spe-cies.

RESULTS We discovered a total of six ground nests (2.1%)

of Scaly-naped Pigeon (Patagioenas squamosa), White-crowned Pigeon (P. leucocephala), and Zenaida Dove on two cays (Green Cay, Protestant Cay) out of 288 nests of five species of columbids (Table 1). The proportion of ground nests was low on cays with (1.5%) or without rats (3.4%). Most of our data, other than White-crowned Pigeon at Ruth Island, were from Green Cay and Protestant Cay.

All six ground nests were discovered in early successional habitats, not in open woodland or for-est. The Scaly-naped Pigeon nest on Protestant Cay that contained one fresh egg on 27 June 2002 (when an adult was flushed off the nest) was placed on soil underneath a sapling (1.5 m) wild tamarind (Leu-

caena leucocephala) 15 cm from a dilapidated rock-wall near the top of a slope on hotel grounds in an

MCNAIR AND LOMBARD — COLUMBID NESTING ECOLOGY ON CAYS OFF ST. CROIX


area that had been cleared of vegetation three weeks earlier. One ground nest of the Zenaida Dove on Protestant Cay, discovered with two eggs on 14 May 2003, was completely shaded by a sapling wild tamarind 18 cm from the same rockwall as the Scaly-naped Pigeon nest in an adjacent area that had been cleared in November 2002. The other Protes-tant Cay nest, with two eggs on 3 May 2002, was placed among low herbaceous vegetation on the beach beside an abandoned unfenced tennis court. The two Zenaida Dove nests on Green Cay, discov-ered with two eggs each on 19 August 2002 and 29 May 2003, were underneath two shrubs Eupatorium

sinuatum and Oplonia spinosa in grassland-scrub near the northeastern tip. The two eggs in the White-crowned Pigeon nest discovered on 29 May 2003 were placed under overhanging boulders on a 60° slope on the leeward side near the top of the peak of the northern tip of Green Cay; by 17 June this nest contained two large nestlings about to fledge. Except for this nest, the other five ground nests of these columbids failed, at least four during the egg stage (only the Zenaida Dove nest under-neath the Eupatorium and Spinosa on Green Cay in 2002 may have survived to the nestling stage).

Some above-ground nests were placed in unusual nest-sites. One Scaly-naped Pigeon nest at Protes-tant Cay was located at a height of 0.5 m above ground on a dry upturned tree trunk along a steep hillside, and another nest at a height of 1.5 m was built on a coralita vine (Antigonon leptopus) lying on top of a large remnant trunk of a tree that had been recently cut down. One White-crowned Pigeon

nest was placed on a ledge inside an open rusted hull of a ship 2.4 m above the water line, just off the shoreline of Ruth Island. Another pair of White-crowned Pigeons on Protestant Cay built a bulky nest on the top of the tip of a live banana frond that lay upon the corner of a window sill of an unoccu-pied dwelling 3.3 m above the ground. Zenaida Doves twice nested on the seat of a table chair (0.75 m above ground) placed 2 m inside this same dwell-ing. Finally, one pair of Zenaida Doves built a nest on Ruth Island (where the species is scarce) at a height of 2 m on top of a fold of a large, torn, hori-zontal tarpaulin that served as the roof for a tempo-rary fishing shack.

DISCUSSION

The six ground nests plus at least seven unusual sites for above-ground nests again demonstrate flexible nest-site placement of columbids on inhab-ited and uninhabited cays (Rivera-Milan 1999, Rivera-Milan and Schaffner 2002). The ground nest of the Scaly-naped Pigeon on Protestant Cay is the first documented for this species, which generally nests high in large, tall trees. The minimum nest heights above ground reported for Puerto Rico were a few nests just off the ground in well supported stunted trees or shrubs in elfin forest in the Sierra de Luquillo (J. W. Wiley pers. comm.) and 1 m above ground in a sea grape (Coccoloba uvifera) at Fla-menco, Culebra (F. F. Rivera-Milan pers. comm.). Despite considerable nest-site flexibility on near-shore cays off St. Croix, we found few columbid ground nests, even on cays without rats where rocky

Table 1. The number of ground versus above-ground nests for five species of columbids on four cays (with rats, Ruth Island and Protestant Cay; without rats, Buck Island and Green Cay) off St. Croix, US Virgin Islands, from 2002 and 2003.

Numbers of Ground / Above-ground Nests

Rats

Species Ruth Island Protestant Cay Buck Island Green Cay Total

Scaly-naped Pigeon White-crowned Pigeon White-winged Dovea Zenaida Dove Common Ground-Doveb Total

0 / 107 0 / 14

0 / 1 0 / 4

0 / 126

1 / 17 0 / 13

2 / 41

3 / 71

0 / 2

0 / 1

0 / 3

1 / 19

2 / 45 0 / 18 3 / 82

1 / 17 1 / 141 0 / 14 4 / 88 0 / 22

6 / 282 aZenaida asiatica bColumbina passerina

No rats



and grassland-scrub habitat was available. Whereas our searches were opportunistic and uneven as to species, site, and year, we are confident that only a small proportion of columbid nests on these cays are ground nests. The scarcity and failure of all but one of these ground nests on cays with and without rats, with or without seabird colonies (cf. Burger et al. 1991), and their restriction to early successional habitats suggest that columbids may prefer breeding above-ground when suitable nest-sites are available in more mature habitats. Predation effects by native fauna probably reduce the incidence of ground nest-ing on cays even where rats (and other exotic preda-tors) may be absent, unless no other habitat is read-ily available on more exposed cays such as Cayo del Agua in the Culebra Archipelago or Saba Cay and Flat Cay off St. Thomas. Land crabs are probably the major predators of columbid nests on cays off St. Croix, except possibly Buck Island where the Pearly-eyed Thrasher (Margarops fuscatus) is fairly numerous (cf. Wiley 1991).

ACKNOWLEDGMENTS We thank Hotel-on-the-Cay for providing us boat

transportation to reach Protestant Cay, J. Johnson of the Tamarind Reef Hotel for providing kayaks that allowed us to reach Green Cay, Z. Hillis-Starr of the National Park Service for allowing us to reach Buck Island on their boat, and M. A. Mahoney for allow-ing us access to St. Croix Renaissance Park where we launched kayaks provided by W. Coles. We also thank J. W. Wiley for reviewing a penultimate draft of this manuscript and W. J. Arendt and two anony-mous individuals for their reviews of the submitted manuscript. McNair also thanks the USFWS for financial support (Federal Aid Program, Pittman-Robertson Columbids Project, W12, Study 1) and Christine Willis for her support. Copies of unpub-lished manuscripts listed below are available from the first author.

LITERATURE CITED ATKINSON, I. A. E. 1985. The spread of commensal

species of Rattus to oceanic islands and their ef-fects on island avifaunas. Pp. 35-81 in Conserva-tion of island birds (P. J. Moors, ed.). ICBF Tech-nical Publication 3. Washington: Smithsonian Institution Press.

BURGER, J., M. GOCHFELD, D. J. GOCHFELD, AND J. E. SALIVA. 1989. Nest site selection in Zenaida Dove (Zenaida aurita) in Puerto Rico. Biotropica 21:244-249.

BURGER, J., M. GOCHFELD, J. E. SALIVA, D. J. GOCHFELD, D. A. GOCHFELD, AND H. MORALES. 1991. Habitat use by visiting Zenaida Doves Zenaida aurita in Puerto Rico: avoidance of is-lands without nesting seabirds. Ornis Scandi-navica 22:367-374.

CAMPBELL, E. W. 1991. The effect of introduced roof rats on bird diversity of Antillean cays. Jour-nal of Field Ornithology 62:343-348.

DAMMANN, A. E., AND D. W. NELLIS. 1992. A natural history atlas to the cays of the U. S. Virgin Islands. Pineapple Press, Inc., Sarasota, FL.

MCNAIR, D. B. 2003. Population estimate, habitat associations, and conservation of the St. Croix Ground Lizard Ameiva polops at Protestant Cay, United States Virgin Islands. Caribbean Journal of Science 39:94-99.

NELLIS, D. W., R. A. DEWEY, M. A. HEWITT, S. IMSAND, R. PHILIBOSIAN, AND J. A. YNTEMA. 1984. Population status of Zenaida Doves and other columbids in the Virgin Islands. Journal of Wildlife Management 48:889-894.

RIVERA-MILAN, F. F. 1999. Population dynamics of Zenaida Doves in Cidra, Puerto Rico. Journal of Wildlife Management 63:232-244.

RIVERA-MILAN, F. F., AND F. C. SCHAFFNER. 2002. Demography of Zenaida Doves on Cayo del Agua, Culebra, Puerto Rico. Condor 104:587-597.

WILEY, J. W. 1991. Ecology and behavior of the Zenaida Dove. Ornitología Neotropical 2:49-75.

WITMER, G. W., F. BOYD, E. CAMPBELL, III, J. WAKEFIELD, AND Z. HILLIS-Starr. 2002. The eradication of introduced rats at Buck Island Reef National Monument, St. Croix, U. S. Virgin Is-lands. Final report. U.S. Department of Interior, National Park Service, Buck Island Reef National Monument, Christiansted, St. Croix, U. S. Virgin Islands.

WOODBURY, R. O., AND E. L. LITTLE, JR. 1976. Flora of Buck Island Reef National Monument (U. S. Virgin Islands). U. S. Dept. Agric. Forest Service, Institute of Tropical Forestry, Río Pie-dras, Puerto Rico.

WOODBURY, R. O., AND J. L. VIVALDI. 1982. The vegetation of Green Cay. U. S. Fish and Wildlife Service contract report no. CI-007-6-1. Files: Caribbean Islands National Wildlife Refuge (P. O. Box 510, Boqueron, Puerto Rico).

YNTEMA, J. A., AND F. W. SLADEN. 1987. Ruth Island survey. Final report, endangered species project ES-1, Study IIB, Job IIB-1. Division of Fish and Wildlife, U. S. Virgin Islands.



VARIATION AND HYBRIDIZATION IN THE GREEN HERON (BUTORIDES VIRESCENS) AND STRIATED HERON (B. STRIATA)

IN TRINIDAD AND TOBAGO, WITH COMMENTS ON SPECIES LIMITS

FLOYD E. HAYES

Department of Life Sciences, University of the West Indies, St. Augustine, Trinidad and Tobago.

Current address: Department of Biology, Pacific Union College, Angwin, CA 94508, USA. [email protected] Abstract: The rufous-necked Green Heron (Butorides virescens) of North America and the Caribbean hybridizes with the gray-necked Striated Heron (B. striata) of South America in Panama and southern Caribbean islands. I ana-lyzed historic and current variability of the two taxa in Trinidad and Tobago by comparing museum specimens and live individuals in the field with a color photograph of nine voucher specimens used as a hybrid index. In Trinidad, the population is dominated by B. striata, whereas B. virescens and intermediate individuals are rare. In Tobago, B.

virescens is the predominant form, with small numbers of B. striata and intermediate individuals. The increased variability and intermediacy of individuals in Tobago strongly implies hybridization, and the higher proportion of intermediate individuals among museum specimens suggests a shift within the past century toward relatively “pure” phenotypes. Neck color was unrelated to clinal variation, seasonality, or habitat. The distribution of phenotypes dif-fers markedly between populations of Butorides in Trinidad and Tobago, which are separated by only 36 km, sug-gesting that competitive exclusion may preclude B. virescens from colonizing Trinidad and B. striata from coloniz-ing Tobago. Because the two taxa may often have opportunities to interbreed on Tobago but tend to mate assorta-tively, they appear to have achieved essential reproductive isolation, thus supporting their current treatment as dis-tinct species. Key words: Butorides striata, Butorides virescens, Green Heron, hybridization, species limits, Striated Heron, Tobago, Trinidad, variation Resumen: VARIACIÓN E HIBRIDIZACIÓN DE LA GARCITA VERDE (BUTORIDES VIRESCENS) Y LA GARCITA ESTRIADA (B. STRIATA) EN TRINIDAD Y TOBAGO, CON COMENTARIOS ACERCA DE LOS LÍMITES DE LA ESPECIE. La Garcita Verde (Butorides virescens) con cuello rufo de Norteamérica y el Caribe se hibridiza con la Garcita Estriada (B.

striata) con cuello griz de Suramérica, en Panamá y las islas caribeñas del sur. Se analizó la variabilidad histórica y actual de ambos taxas a través de la comparación de especímenes de museo y animales vivos con una fotografía a color de nueve de nueve ejemplares utilizados como patrones del híbrido. En Trinidad la población está dominada por B. striata, mientras que B. virescens e individuos intermedios son raros. En Tobago, B. virescens es la forma predominante, con pequeños números de B. striata e individuos intermedios. La variabilidad incrementada incre-mentada y los caracteres intermedios en los individuos de Tobago sugieren fuertemente hibridización y la mayor proporción de individuos intermedios entre los especímenes de museo sugiere un cambio en el siglo pasado hacia los fenotipos “puros”. El color del cuello no estuvo relacionado a variaciones clinales, estacionales o de hábitat. La dis-tribución de los fenotipos difiere marcadamente entre las poblaciones de Butorides en Trinidad y Tobago, que estan separadas tan solo por 36 km, lo que sugiere que la exclusión competitiva evita la colonización de Trinidad por B.

virescens y la de Tobago por B. striata. Como ambos taxas tienen frecuentes oportunidades de entrecruzarse en To-bago, pero tienen un apareamiento asociativo, parece ser que han alcanzado un aislamiento reproductivo esencial que apoya su tratamiento actual como especies diferentes. Palabras clave: Butorides striata, Butorides virescens, Garcita Estriada, Garcita Verde, hybridización, límites de especies, Tobago, Trinidad, variación Résumé : VARIABILITE ET HYBRIDATION ENTRE LE HERON VERT (BUTORIDES VIRESCENS) ET LE HERON STRIE (B.

STRIATA) A TRINITE ET TOBAGO: COMMENTAIRES SUR LES FRONTIERES D’ESPECES. Le Héron vert (Butorides vires-

cens) à cou roux d’Amérique du Nord et de la Caraïbe, se croise avec le Héron strié, à cou gris d’Amérique du Sud, du Panama et des îles du sud des Antilles (B. striata). J’ai étudié la variabilité historique et actuelle et deux taxons à Trinité et Tobago en comparant des spécimens de Muséum et des individus vivants en liberté avec des clichés en couleur de neuf spécimens utilisés comme index hybride. A Trinité, la population est dominée par B. striata, alors que B. virescens et les individus intermédiaires sont rares. A Tobago, B. virescens est la forme prédominante, avec un nombre faible de B. striata et d’individus intermédiaires. La plus variabilité et situation intermédiaire croissante à Tobago implique fortement la présence d’hybridation et la plus grande proportion d’individus intermédiaires dans les spécimens de Muséums suggère une dérive pendant le siècle passé vers des phénotypes relativement « pures ». La couleur du cou n’est pas liée à une variation clinale, ou de saisonnalité ou d’habitat. La distribution des phénoty-pes diffère nettement entre les populations à Butorides de Trinidad et de Tobago, séparées de seulement 36 km, sug-gérant qu’une exclusion compétitive empêche B. virescens de coloniser Trinidad et B. striata de coloniser Tobago.



HYBRIDIZATION, THE INTERBREEDING between morphologically distinct populations in secondary contact (Short 1969), is a genetic phenomenon widespread in birds, even between non-sister taxa (Grant and Grant 1992), and can be inferred pheno-typically by an increase in variability and interme-diacy in the contact zone (Schueler and Rising 1976). Where zones of phenotypic intermediacy occur between parapatrically distributed taxa, docu-menting the gradient of change in geographic varia-tion and the distribution of phenotypes (or, prefera-bly, genotypes) within the contact zone is important to distinguish between primary intergradation (clinal variation) and secondary intergradation (hybridization), to infer the extent of gene flow and the development of isolating mechanisms, and to interpret the taxonomic significance of hybridiza-tion (e.g., Remington 1968, Short 1969, Woodruff 1973, Schueler and Rising 1976, Moore 1977, Bar-ton and Hewitt 1985a, b, Harrison 1990). The heron genus Butorides has been the subject of a disputed taxonomic history that remains unre-solved. Two species are currently recognized: (1) the rufous-necked Green Heron (B. virescens) of North America, Central America, and the West In-dies; and (2) the gray-necked Striated Heron (B.

striata) of South America (including dark B. s. sun-

devalli of the Galápagos Islands), Eurasia, Africa, and Australia (American Ornithologists’ Union 1998, Banks et al. 2003). David and Gosselin (2002) recently pointed out that Butorides is femi-nine, requiring that B. striatus be changed to B. stri-

ata (Banks et al. 2004). The two forms were gener-ally treated as distinct species (e.g., Peters 1931, Hellmayr and Conover 1948, Bock 1956, Palmer 1962, Wetmore 1965), but sometimes considered conspecific (Hartert 1920) or possibly conspecific (Eisenmann 1952, Parkes 1955), until Payne (1974) provided evidence of extensive hybridization be-tween B. virescens and B. striata where their ranges meet in southern Central America, several southern Caribbean islands, and coastal northern South America. Based on the conclusions of Payne (1974, 1979) and Payne and Risley (1976), the American Ornithologists’ Union (1976, 1983) lumped the two forms into the Green-backed Heron (B. striata).

In a subsequent reanalysis of specimens from the Panamanian contact zone between B. virescens and B. striata, Monroe and Browning (1992) concluded that Payne’s (1974) voucher specimens used as a hybrid index included juveniles and did not repre-sent a continuous series. They concluded that B.

virescens and B. striata seldom hybridized and should be regarded as distinct species. The Ameri-can Ornithologists’ Union (1993, 1998) accepted their conclusions. Hayes (2002), however, demon-strated that Payne’s (1974) voucher specimens had all attained adult neck coloration and represented a continuous series; furthermore, a reanalysis of Payne’s (1974) data demonstrated increased vari-ability and intermediacy in the contact zone be-tween B. virescens and B. striata, implying exten-sive hybridization. Because phenotypically “pure” B. virescens and B. striata phenotypes coexisted within the contact zone, Hayes (2002) tentatively concluded that assortative mating occurred, support-ing their treatment as distinct species, but noted that the sample size of museum specimens was small and it remained uncertain whether both parental phenotypes actually bred within the hybrid zone. At the eastern end of the hybrid zone, the ranges of B. v. virescens (resident throughout eastern North America, Central America, and the Caribbean) and B. s. striata (resident throughout South America) meet in Trinidad and Tobago, where populations are dominated by B. striata in Trinidad but by B. vires-

cens on Tobago (ffrench 1973, 1991). On the latter island, individuals of both species and intermediates have been collected (Payne 1974). In this paper I document historic and current variability of the two taxa in Trinidad and Tobago, and attempt to assess several potential environmental correlates for vari-ability (clinal variation, seasonality, or habitat), infer the degree of gene flow and development of reproductive isolation between the two taxa, and interpret the taxonomic significance of hybridiza-tion.

STUDY AREA AND METHODS STUDY AREA Trinidad and Tobago are large continental islands

HAYES — BUTORIDES HERONS IN TRINIDAD AND TOBAGO

Bien que les deux taxons on des possibilités de se croiser à Tobago, ils tendent à s’associer préférentiellement de manière homogène. Ils semblent donc avoir atteint un isolement reproductif suffisant, allant donc dans le sens de leur traitement actuel en tant qu’espèce séparé. Mots-clés : Butorides striata, Butorides virescens, Héron strié, Héron vert, hybridation, limites d’espèces, Tobago, Trinité, variabilité


located on the continental shelf of South America just north of the Orinoco River Delta (Fig. 1). Situ-ated only 19 km from the continental mainland, Trinidad is larger (4520 km2) and higher in eleva-tion (up to 925 m), and possesses a greater diversity of wetlands (Kenny and Bacon 1981). Freshwater wetlands include rivers, swamps, marshes, rice fields, reservoirs, fish ponds, drainage canals, and sewage ponds; saltwater wetlands include mangrove swamps, salt marshes, river mouths, and mudflats. Tobago is located farther from the continent (118 km) but only 36 km from Trinidad; being smaller in size (306 km2) and lower in elevation (up to 576 m), Tobago’s wetlands average smaller and rice fields are lacking. METHODS I photographed a series of nine voucher speci-mens used by Payne (1974) as a hybrid index in which neck coloration was scored from 1-9, ranging from gray to dark purplish brown (see Fig. 1 of Hayes 2002). Specimens scored 1-4 (gray to brownish gray) occur throughout the South Ameri-can range of B. striata and specimens scored 6-9 (grayish red-brown to purplish brown) occur throughout the North American range of B. vires-

cens (Payne 1974, Hayes 2002). Potential hybrids, especially those that have backcrossed with a paren-tal phenotype, may be difficult to distinguish from presumably “pure” phenotypes. Individuals scored as 5 occur only in the hybrid zone and in isolated B.

v. bahamensis of the Bahamas; thus, individuals with a neck coloration score of 5 in Trinidad and Tobago presumably represent hybrids, but those with lower or higher neck coloration scores (especially 4 or 6) may also be hybrids (Payne 1974, Hayes 2002). Direct comparisons with a color photograph of hybrid index specimens were used to score neck coloration of museum specimens or photographs of museum specimens collected in Trinidad and To-bago from 1897 to 1913 (see Acknowledgments), and for live individuals observed throughout the country from October 2000 to August 2002. When an individual appeared intermediate in neck colora-tion between two voucher specimens, which often occurred, I chose the specimen it most closely re-sembled. Because juveniles and immatures have streaked necks (always browner than adults of S.

striata), only adults and subadults that had fully acquired adult neck coloration (Hayes 2002) were scored. Because the apparent shade of neck colora-tion tended to vary by ±1 score depending on the

angle of lighting, the only individuals scored were non-flying individuals carefully observed from the side in good lighting conditions with binoculars (7×) or a telescope (25×). Because many localities were sampled repeatedly (up to 28 times) to obtain large sample sizes, and because none of the birds were banded or marked, many individuals were probably sampled repeat-edly. To minimize the probability of including re-peated samples in the following analyses, I chose the highest number of individuals scored within a day for each locality separated by a distance of >1 km from the nearest locality, and excluded data sampled on other days. In addition to the two is-lands (Trinidad and Tobago), localities were lumped into four arbitrarily defined regions to test for clinal variation: (1) western Trinidad, (2) central and east-ern Trinidad, (3) western Tobago, and (4) central and eastern Tobago (Fig. 1). To evaluate potential environmental correlates of variability in neck color, I recorded the following variables for each heron examined: (1) water salin-ity as either fresh or salt (including brackish); (2) presence or absence of a patch of mangroves (Rhizophora mangle, Avicennia germinans, Lagun-

cularia racemosa, or Conocarpus erecta) > 0.25 ha in area within 50 m of the individual; and (3) sea-son, with March-May as spring, June-August as summer, September-November as autumn, and De-cember-February as winter. STATISTICAL ANALYSES Because neck coloration scores were ordinally ranked and did not meet the assumptions of para-metric statistical tests, nonparametric Mann-Whitney U tests (U or z statistic), Kruskal-Wallis tests (H statistic), and two-sample chi-square tests with Yates correction (χ2 statistic) were used when appropriate to compare the distribution of neck col-oration scores between geographic regions, time periods, and habitat classes, respectively (Zar 1998). All probabilities are two-tailed with α = 0.05.

RESULTS HISTORICAL STATUS IN TRINIDAD Anecdotal accounts of early ornithologists and a limited number of specimens indicate that Trinidad historically has been inhabited primarily by B. stri-

ata (Belcher and Smooker 1934, Junge and Mees 1958, Herklots 1961, ffrench 1973). Belcher and Smooker (1934:579) reported that B. virescens was a rare breeding resident whose eggs were described



as “more rounded on the average” than those of B.

striata. Herklots (1961) reported sight records of B.

virescens, but provided no further details. ffrench (1973) regarded the purported breeding of B. vires-

cens in Trinidad as uncertain and suggested that sight records pertained to migrants. Payne (1974) reported neck coloration scores of four specimens from Trinidad ranging from 1-3 (0 = 1.5, SD = 1.0). The six specimens I examined from Trinidad, col-lected from 1902 to 1951 (BMNH, USNM, YPM), ranged from 1-3 (0 = 1.5, SD = 0.8) and did not differ significantly from Payne’s (1974) sample (U = 15.5, P = 0.43). CURRENT STATUS IN TRINIDAD Of 40 individuals examined in the field, neck coloration scores varied from 1-6, with 57.5% scored as 1 and 95% with a score of 1-3 (0 = 1.7, SD = 1.1; Table 1). Although no specimens of B.

virescens were collected, three sightings were ac-cepted recently by the Trinidad and Tobago Rare Bird Committee, including two subadults with adult neck coloration at Trincity on 31 January 1998, a presumed adult at Pointe-a-Pierre on 21 March 1998, and an adult at San Rafael on 10 January

1999 (White and Hayes 2002). However, neck col-oration was not scored on any of these individuals. Intermediate individuals were rare in Trinidad. Birds with a neck coloration score of 4, representing brown-necked B. striata or hybrid B. virescens × striata, were recorded at Caroni on 2 June 2001 and at Pointe-a-Pierre on 7 October 2000 (see Hayes 2002 for a photograph of the latter). A presumed hybrid individual with a score of 5 was seen at Caroni on 28 June 2001 and on 19 April, 30 May, and 2 June 2002. Adults with neck coloration scores of 6, representing either B. virescens or hybrids, were noted at Cacandee on 21 April 2001 and at Fullarton on 26 May 2002. HISTORICAL STATUS IN TOBAGO In the late 19th and early 20th centuries, Tobago was inhabited by both taxa of Butorides with a high proportion of intermediate individuals. Belcher and Smooker (1934) regarded B. striata as common and B. virescens as rare. Perhaps influenced by Belcher and Smooker (1934), Junge and Mees (1958) re-ported that B. striata was more common but the only specimen collected was B. virescens. In con-trast to earlier reports, Herklots (1961) and ffrench


Fig. 1. Sampling localities of Butorides herons in Trinidad and Tobago during 2000-2002. Dashed lines on each island represent the division of regions: (a) western Trinidad, (b) central and eastern Trinidad, (c) western Tobago, and (d) central and eastern Tobago.


(1973) reported B. virescens as a common resident. Herklots (1961) attributed several sight records of B. striata in Tobago to R. ffrench, who later re-garded sight records of B. striata in southwest To-bago as uncertain (ffrench 1973) and eventually omitted the species from Tobago’s avifauna (ffrench 1996). Payne (1974) reported neck colora-tion scores of 13 specimens from Tobago ranging from 3-8 (0 = 5.38, SD = 1.33; Table 1), indicating that both taxa as well as intermediates were present. Neck coloration scores from 18 specimens I exam-ined from Tobago, collected from 1892-1913, also

ranged from 3-8 (0 = 5.72, SD = 1.41; Table 1 and Appendix) and did not differ significantly from Payne’s (1974) sample (U = 131.5, P = 0.55). The proportion of specimens with a neck coloration score of 5 (presumed hybrids) varied from 31% (Payne 1974) to 28% (this study). CURRENT STATUS IN TOBAGO Of 50 individuals examined in the field, neck coloration scores ranged from 1-8 (0 = 5.86, SD = 1.84; Table 1). Mean neck coloration scores did not differ significantly from the museum specimens I

Table 1. Frequency of neck color scores of Butorides herons in different time periods, islands, regions, seasons, water salinities, and habitats. Specimen data from Trinidad are insufficient for analysis. Data for region, season, salinity, and habitat are based on live individuals observed from 2000-2002.

Variable 1 2 3 4 5 6 7 8

Island Trinidad (2000-2002) Tobago (Payne 1974) Tobago (1892-1913) Tobago (2000-2002) Region western Trinidad central/eastern Trinidad western Tobago central/eastern Tobago Season: Trinidad summer autumn winter Season: Tobago summer autumn winter Water salinity: Trinidad freshwater saltwater Water salinity: Tobago freshwater saltwater Habitat: Trinidad mangroves non-mangroves Habitat: Tobago mangroves non-mangroves

23 0 0 1

16 7 1 0

11 9 3

0 1 0

15 8

1 0

5 18

0 1

10 0 0 4

9 1 4 0

7 1 2

1 3 0

5 5

4 0

4 6

0 4

5 2 2 3

4 1 3 0

4 1 0

0 3 0

3 2

3 0

2 3

0 3

1 0 0 2

1 0 0 2

0 1 0

0 2 0

1 0

1 1

0 1

0 2

0 4 5 3

0 0 3 0

1 0 0

1 2 0

0 1

1 2

1 0

1 2

1 6 8 12

1 0 8 4

0 0 0

2 6 4

0 0

9 3

0 0

1 11

0 0 0 20

0 0 14 6

0 0 0

6 10 4

0 0

12 7

0 0

4 16

0 1 3 5

0 0 3 2

0 0 0

3 2 0

0 0

5 0

0 0

0 5

Neck Color Scores



examined (z = 1.21, P = 0.23). However, when neck scores were lumped into three categories (1-3, 4-6, and 7-8), proportionately more intermediate pheno-types (scores of 4-6) occurred among specimens (72%) than live individuals (34%; Table 1) and the distribution of neck scores differed significantly between live individuals and specimens (χ2 = 8.17, df = 3, P = 0.02). Presumed B. virescens with scores of 7-8 comprised 50% of the population and pre-sumed B. striata with scores of 1-3 comprised 16% of the population (Table 1). Presumed hybrids with a score of 5 comprised only 6% of the population (Table 1), significantly less than the specimens I examined (28%; χ2 = 4.13, df = 1, P = 0.04). No birds were observed with a neck score of 9, which is very rare in B. virescens (1.4% of 147 specimens from the Greater and Lesser Antilles; Payne 1974). Mean neck coloration scores were significantly higher in Tobago than in Trinidad (z = 7.43, P < 0.001). The only specimens of adult B. striata taken in Tobago were two males with neck coloration scores of 3 collected at Sandy Point on 25 April 1903 (AMNH 469318, 469318). An adult B. striata at Buccoo from 17 January to 9 February 1998 was the first sighting accepted by the Trinidad and Tobago Rare Bird Committee (White and Hayes 2002). Be-tween 24 May and 7 August 2001, I identified a minimum of six (up to four seen in a day) adult B.

striata with neck coloration scores of 1-3 in south-western Tobago. The following year, I found three different adult B. striata with scores of 1-3 in south-western Tobago on 11 June 2002. A B. striata with a neck score of 1-3 (seen too briefly to score) was seen at Englishman’s Bay, north-central Tobago, on 8 October 2001. ENVIRONMENTAL CORRELATES Significant variation in neck coloration occurred among the four regions (H = 56.5, P = 0.006; Table 1). However, nonparametric multiple comparison tests revealed no significant differences between the two Trinidad regions or between the two Tobago regions (P > 0.05). Each region in Trinidad differed from both regions in Tobago and each region in Tobago differed from both regions in Trinidad (P < 0.05). Neck coloration did not differ significantly among seasons in either Trinidad (H = 1.86, P = 0.39) or Tobago (H = 4.3, P = 0.12), between fresh-water and saltwater habitats in Trinidad (U = 214.5, P = 0.50) or Tobago (U = 271, P = 0.68), or be-tween mangrove and non-mangrove habitats in Trinidad (U = 208, P = 0.19) or Tobago (U = 152.5,

P = 0.53; Table 1).

DISCUSSION Although some criticize the use of a hybrid index as crude and subjective, Corbin and Barrowclough (1977) demonstrated that independent studies yielded nearly identical results. With regard to Payne’s (1974) hybrid index specimens, I found a color photograph of the specimens to be highly use-ful and reasonably accurate for scoring neck colora-tion of museum specimens and in the field. Payne (1974) and I examined specimens independently, yet obtained similar results. When colleagues ac-companied me in the field and shared excellent views of an individual, their independent assess-ment of neck coloration was always within ±1 score of my own. The resident population of Butorides in Trinidad is dominated by gray-necked B. striata (scores of 1-2) with a minority of brown-necked individuals (scores of 3-4) within the normal range of variation throughout South America. The range of dates for B. virescens (10 January to 26 May) suggests that it is a rare visitor to Trinidad, either as a Nearctic mi-grant or a visitor from Tobago. There is no credible evidence that B. virescens has ever bred in Trinidad. In Tobago, the current population consists pre-dominantly of B. virescens, with a small number of B. striata and intermediate individuals. The higher proportion of intermediate individuals among mu-seum specimens, probably contributing to the uncer-tainty of earlier accounts by ornithologists, suggests a phenotypic shift within the past century toward relatively pure phenotypes. Some individuals of B.

virescens may represent migrants from farther north, but if so, the proportion is likely small, given the rarity of B. virescens in Trinidad. Whether B.

striata actually breeds in Tobago or is a rare but regular non-breeding visitor from Trinidad remains uncertain (breeding of Butorides herons in Tobago is poorly documented). My observations of multiple individuals during the wet season coincided with the peak breeding season for wading birds in Trinidad, including Butorides herons, as well as the peak sea-son for vagrancy of non-breeding waterbirds from mainland South America (ffrench 1991). The in-creased variability and intermediacy of the Tobago population, in contrast with its neighboring islands in the Lesser Antilles and Trinidad (Payne 1974, Hayes 2002), strongly implies hybridization, indi-cating that at least some B. striata breed in Tobago. There is no evidence that neck color variability in Trinidad and Tobago is related to clinal variation



within an island, seasonality, or habitat. The seem-ingly continuous variation in neck color from gray to purplish-brown strongly implies polygenic con-trol of the deposition of gray eumelanin and rufous phaeomelanin pigments in the distal barbules of neck feathers (Schodde et al. 1980). Brown-necked individuals of B. striata with elevated levels of ru-fous phaeomelanin pigments in the neck also tend to have more extensive rufous on the underparts and wing covert margins than gray-necked individuals (Hayes pers. obs.). Whether neck color variability in B. virescens and B. striata is adaptive or represents genetic drift in isolated populations remains un-known, but the darker coloration of B. s. sundevalli in the Galápagos Islands is thought to enhance for-aging success in a backdrop of bare, blackish lava (Snow 1975). The distribution of phenotypes differs markedly between populations of Butorides in Trinidad and Tobago, which are separated by only 36 km. An accomplished disperser, B. virescens is widely dis-tributed on islands throughout the Caribbean, in-cluding Tobago, but only rarely visits Trinidad, suggesting that competitive exclusion by resident B.

striata precludes it from successfully colonizing the island. Small numbers of B. striata frequently wan-der to Tobago from Trinidad or mainland South America, and vagrancy within the Caribbean has been documented on St. Vincent in the Lesser Antil-les (AMNH 325358, with a neck score of 3, taken on 18 July 1924; Bond 1964, Payne 1974) and St. John in the Greater Antilles (neck score of 2, pre-sent from 25-29 May 2003; F. E. Hayes unpubl. photos). My observations in 2001 and 2002 suggest that small numbers of B. striata visit Tobago fre-quently enough to form a small breeding popula-tion, yet the island’s population of Butorides re-mains dominated by relatively “pure” B. virescens phenotypes, suggesting that competitive exclusion precludes the successful establishment of B. striata. The historical shift toward relatively “pure” pheno-types of both taxa in Tobago suggests the occur-rence of assortative mating despite occasional hy-bridization. Because the two taxa may have frequent opportunities to interbreed freely on Tobago but interbreed only occasionally, they appear to have achieved essential reproductive isolation (Johnson et al. 1999), thus supporting their current treatment as distinct species. Given that these two taxa, which differ morpho-logically only in neck (and perhaps belly) colora-tion, appear to behave as distinct species, the num-ber of species in Butorides, which includes up to 26

subspecies currently subsumed within B. striata and four within B. virescens (Hanckock and Kushlan 1984, Hayes 2002), may be greater than currently recognized. Finally, these conclusions are based on the inherent limitations of scoring live individuals in the field based on specimen scores, and inferring gene flow from phenotype. Behavioral studies of mated pairs and genetic analyses are needed to ade-quately resolve the species limits of Butorides her-ons.

ACKNOWLEDGMENTS I thank P. A. Buckley, D. B. McNair, R. B. Payne, J. V. Remsen, Jr., and an anonymous re-viewer for reviewing earlier drafts. Field work in Trinidad and Tobago was funded indirectly by Car-ibbean Union College, the Tobago House of Assem-bly, and the University of the West Indies. For their companionship and patience in the field I thank B. Hayes, M. Hayes, M. Kenefick, K. Lallsingh, N. Lallsingh, and numerous others who accompanied me less frequently. Examination of museum speci-mens in the U. S. National Museum of Natural His-tory (USNM) and the American Museum of Natural History (AMNH) was financed by a Study and Travel Grant from the University of the West In-dies, St. Augustine. For their assistance with mu-seum specimens, I thank C. Angle (USNM), M. Foster (USNM), J. Weicker (AMNH), P. Rasmus-sen (USNM), and P. Sweet (AMNH). I also thank J. Bates and D. Willard for loaning specimens from the Field Museum of Natural History (FMNH), M. Adams for providing photographs of specimens in the (British) Natural History Museum (BMNH), G. Frisk for providing photographs of a specimen in the (Swedish) Naturhistoriska Riksmuseet (NRM), and K. Zyskowski for providing photographs of specimens in the Yale-Peabody Museum (YPM). I also thank J. Eitniear, A. Kratter, R. Payne, and K. Voous for providing pertinent literature.

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PAYNE, R. B. 1974. Species limits and variation of the New World Green Herons Butorides virescens and Striated Herons B. striatus. Bulletin of the British Ornithologists’ Club 94:81-88.

PAYNE, R. B. 1979. Family Ardeidae. Pp. 193-243 in Check-list of birds of the World, vol. 1, 2nd ed. (E. Mayr and G. W. Cottrell, eds.). Harvard Uni-versity Press, Cambridge, MA.

PAYNE, R. B., AND C. J. RISLEY. 1976. Systematics and evolutionary relationships among the herons (Ardeidae). Miscellaneous Publications of the Museum of Zoology, University of Michigan 150.

PETERS, J. L. 1931. Check-list of birds of the World, vol. 1. Harvard University Press, Cam-bridge, MA.



Specimen Date (M-D-Y) Sex Neck Color Score

AMNH 156503 AMNH 156504 AMNH 469318 AMNH 469319 AMNH 469320 AMNH 469321 AMNH 469322 AMNH 469223 AMNH 469324 AMNH 469325 BMNH 1914.7.6.2 BMNH 1914.12.1.536 BMNH 1969.43.28 FMNH 33642 FMNH 33659 FMNH 33662 FMNH 33676 NRM 568904

unknown 04-24-1903 04-25-1903 04-25-1903 04-25-1903 04-24-1903 04-24-1903 04-24-1903 03-04-1897 04-27-1903 05-21-1913 12-29-1907 04-24-1903 04-20-1892 04-20-1892 04-15-1892 04-20-1892 04-24-1903

male female male

female male male

female unknown

male unknown unknown unknown unknown

male male male

female male

5 5 3 5 3 6 5 5 6 6 6 6 6 8 8 8 6 6

Appendix. Neck coloration scores of adult Butorides specimens from Tobago examined in this study. AMNH = American Museum of Natural History, New York, NY; BMNH = Natural History Museum, London, UK; FMNH = Field Museum of Natural History, Chicago, IL; NRM = Naturhistoriska Riksmuseet, Stockholm, Sweden.


REMINGTON, C. L. 1968. Suture-zones of hybrid interaction between recently joined biotas. Pp. 321-428 in Evolutionary biology, vol. 2 (T. Dobzhansky, M. K. Hecht, and W. C. Steere, eds.). Appleton-Century-Crofts, New York.

SCHODDE, R., I. J. MASON, M. L. DUDZINSKI, AND J. L. MCKEAN. 1980. Variation in the Striated Heron Butorides striatus in Australasia. Emu 80:203-212.

SCHUELER, F. W., AND J. D. RISING. 1976. Phenetic evidence of natural hybridization. Systematic Zoology 25:283-289.

SHORT, L. L. 1969. Taxonomic aspects of avian hybridization. Auk 86:84-105.

SNOW, B. K. 1975. The Plumbeous Heron of the Galapagos. Living Bird 13:51-72.

WETMORE, A. 1965. The birds of the Republic of Panama. Part 1.--Tinamidae (tinamous) to Ryn-chopidae (skimmers). Smithsonian Miscellaneous Collections 150:1-483.

WHITE, G., AND F. E. HAYES. 2002. Second report of the Trinidad and Tobago Rare Bird Committee. Living World, Journal of the Trinidad and To-bago Field Naturalists’ Club 2002:51-56.

WOODRUFF, D. S. 1973. Natural hybridization and hybrid zones. Systematic Zoology 22:213-218.

ZAR, J. H. 1998. Biostatistical analysis. 4th ed. Prentice-Hall, Inc., Englewood Cliffs, NJ.


THE SIGNIFICANCE OF BONAIRE, NETHERLANDS ANTILLES, AS A BREEDING SITE FOR TERNS AND PLOVERS

JEFFREY V. WELLS1,2 AND ALLISON CHILDS WELLS1,3

1Cornell Lab of Ornithology, 159 Sapsucker Woods Rd., Ithaca, NY 14850; 2current address: Boreal Songbird

Initiative, c/o 210 Water St., Hallowell, ME 04347; e-mail: [email protected]; 3current address: Natural

Resources Council of Maine, 3 Wade St., Augusta, ME 04330

Abstract: We carried out surveys to document numbers of nesting terns and plovers on Bonaire and Klein Bonaire, Netherlands Antilles from 4-7 July 2001. Significant numbers of several species were counted including Snowy Plover (Charadrius alexandrinus; 46 adults), Wilson’s Plover (Charadrius wilsonia; 24-26 adults), and Least Tern (Sternula antillarum; 360 adults) as well as smaller numbers of Royal Tern (Sterna maxima), Sandwich “Cayenne” Tern (Sterna sandvicensis eurygnatha), and Common Tern (Sterna hirundo). Evidence of breeding was found in all but the Royal Tern. Bonaire, Curaçao, and Aruba appear to have regionally significant populations of terns and plov-ers of several species. With increased protection from introduced predators and human disturbance, Bonaire and its sister islands have the potential to become major source populations to maintain southern Caribbean metapopula-tions of terns and plovers. Key words: Charadrius alexandrinus, Charadrius wilsonia, conservation, Netherlands Antilles, plovers, seabirds, Sterna hirundo, Sterna sandvicensis eurygnatha, Sternula antillarum, terns Resumen: LA IMPORTANCIA DE BONAIRE, ANTILLAS HOLANDESAS, COMO SITIOS DE CRÍA PARA LAS GAVIOTAS Y LIMÍCOLAS. Se llevaron a cabo expediciones para documentar las cantidades de gaviotas y limícolas nidificantes en Bonaire y Klein Bonaire, Antillas Holandesas, entre el 4 y el 7 de julio de 2001. Significantes cantidades de varias especies fueron encontradas, incluyendo al Frailecillo Blanco (Charadrius alexandrinus; 46 adultos), al Títere Playero (Charadrius wilsonia; 24-26 adultos), y la Gaviotica (Sternula antillarum; 360 adultos) así como pequeños números de la Gaviota Real (Sterna maxima), la Gaviota de Sandwich “Cayenne” (Sterna sandvicensis eurygnatha) y la Gaviota Común (Sterna hirundo). Evidencias de cría fueron halladas para todas, excepto para la Gaviota Real. Bonaire, Curaçao, y Aruba aparentan tener poblaciones regionalmente significativas de gaviotas y limícolas de varias especies. Con la protección creciente contra depredadores introducidos y disturbios humanos, Bonaire y su isla hermana, tienen el potencial para convertirse en una importante población fuente para la mantención de la meta-población caribeña de gaviotas y limícolas. Palaberas clave: aves marinas, Antillas Holandesas, Charadrius alexandrinus, Charadrius wilsonia, conservación, gaviotas, limícolas, Sterna hirundo, Sterna sandvicensis eurygnatha, Sternula antillarum

Résumé : L’IMPORTANCE DE BONAIRE, ANTILLES NEERLANDAISES, COMME SITE DE NIDIFICATIONS POUR LES STERNES ET LES GRAVELOTS. Nous avons entrepris des recherches du 4 au 7 juillet 2001 pour estimer le nombre de sternes et de gravelots nicheurs à Bonaire et Klein Bonaire, Antilles néerlandaises. Un nombre significatif d’indivi-dus de différentes espèces a été compté, incluant le Gravelot à collier interrompu (Charadrius alexandrinus, 46 adultes), le Gravelot de Wilson (Charadrius wilsonia, 24-26 adultes), et la Petite Sterne (Sternula antillarum, 360 adultes) ainsi que des effectifs plus réduits de Sterne royale (Sterna maxima), de Sterne de “Cayenne” (Sterna sand-

vicensis eurygnatha), et de Sterne pierregarin (Sterna hirundo). Des indices de nidification ont été trouvés pour toutes les espèces à l’exception de la Sterne royale. Bonaire, Curaçao, et Aruba possèdent des populations d’impor-tance régionale pour plusieurs espèces de sternes et de gravelots. Avec une meilleure protection contre les prédateurs introduits et le dérangement humain, Bonaire et ses iles sœurs ont le potentiel pour jouer un rôle majeur dans le maintien des métapopulations de sternes et de gravelots du sud de la’ Caraïbe. Mots-clés : Antilles néerlandaises, Charadrius alexandrinus, Charadrius wilsonia, conservation, gravelots, oiseaux de mer, pluviers, Sterna hirundo, Sterna sandvicensis eurygnatha, sternes, Sternula antillarum

RECENTLY, THERE HAS BEEN increased recogni-tion of the islands of the Caribbean as important breeding areas for various species of waterbirds, including several tern and plover species (Schreiber and Lee 2000). To better understand the relative importance of each site, species abundance and dis-tribution must be documented and monitored

(Schreiber 2000). Using this baseline information, effective conservation actions can be implemented to stabilize and increase populations. In early July 2001, we conducted surveys of tern and plover populations on the island of Bonaire, Netherlands Antilles, and its nearby offshore island of Klein Bonaire. Bonaire and its sister islands of



Curaçao and Aruba have historically been known to harbor breeding populations of a number of species of terns and plovers (Voous 1983). Some surveys have been carried out for a few tern nesting islands (e.g. San Nicolas reef islands on Aruba and Jan Thiel islands on Curaçao) but no comprehensive surveys of breeding terns have been reported for Bonaire and no surveys of plovers have been re-ported for Bonaire, Curaçao, or Aruba. We visited breeding locales on Bonaire noted in Voous (1983) as well as areas we suspected might be used by terns and plovers. Specifically, the species for which we were able to collect baseline breeding population data were Snowy Plover (Charadrius

alexandrinus), Wilson’s Plover (Charadrius wil-

sonia), Royal Tern (Sterna maxima), “Cayenne” Sandwich Tern (Sterna sandvicensis eurygnatha), Common Tern (Sterna hirundo), and Least Tern (Sternula antillarum).

In this paper we provide information on numbers of pairs found at each site, breeding status if known, and information on productivity based on numbers of fledglings observed.

METHODS

We carried out surveys of different sections of Bonaire from 4-7 July and on Klein Bonaire on 7 July 2001. We began our surveys at approximately 06:30 hr and continued until approximately 11:00 hr. We resumed surveys after 16:00 most days, when temperatures had begun to decline, until dusk. To survey areas we drove access roads along coast-line, bays, salt pans, and lagoons and systematically scanned all possible areas with 10×40 binoculars and 20-45× telescope. In areas where it was difficult to effectively view and count with optical equip-ment, we walked toward colonies or nesting areas but in all cases we limited time in the area to reduce

Fig. 1. Areas surveyed for terns and plovers on Bonaire, Netherlands Antilles, in July 2001. Sites identified by letters on the map are keyed to Table 1, which summarizes the numbers of birds, nests, and fledglings found at each site. See the text for survey details. Geographic names for the survey areas identified on the map are as follows: A–west side of Pekelmeer; B–east side of Pekelmeer; C–north side Lac Bay; D–Washikemba; E–shoreline near Boca Onima; F–Salina Matijs; G–Playa Macoshi; H–Malmok Lighthouse; I–Boca Bartol; J–Playa Funchi; K–Salina Wayaca; L–Slagbaai; M–Playa Frans; N–Playa Tam; O–Lake Goto; P–mouth of Goto; Q–southcentral coast; R–Klein Bonaire.

WELLS AND WELLS — BREEDING TERNS AND PLOVERS OF BONAIRE


disturbance. On Klein Bonaire we walked the coast-line approximately half way around the island. The areas surveyed are illustrated in Fig. 1. Our surveys represent minimum numbers present on the islands, since we were unable to visit or view every area. In particular, we were unable to access interior por-tions of the Pekelmeer that are part of the commer-cial salt operations and that harbored major tern colonies in the past. Also, at least in the tern spe-cies, some birds may have already nested and moved away from the islands, since breeding can begin as early as April or May (Voous 1983).

RESULTS SNOWY PLOVER Our surveys documented a total of 46 adults, 40 on mainland Bonaire and six on Klein Bonaire (Fig. 1, Table 1). Evidence of breeding was shown by

seven pairs, five of which were seen with chicks and two that gave distraction displays. Largest num-bers were found in the southern part of Bonaire, especially along the western side of the Pekelmeer (Fig. 1–Site A), the salinas on the north side of Lac Bay (Fig. 1–Site C), and the northeast side of the Pekelmeer (Fig. 1–Site B). Four pairs at the Lac Bay site had chicks ranging from one pair with three chicks to one pair with only one very young (1-3 d old) chick. We also found a concentration of 8 adults in the southern part of the Lake Goto (Fig. 1–Site O). Two pairs, apparently nesting along the roadside, gave distraction displays. We counted six adults on Klein Bonaire (Fig 1–Site R), all near an area marked as Tanki Kalabas on some maps. There, one chick was observed with a pair of adults. WILSON’S PLOVER Our surveys documented a total of 24-26 adults,

Survey Site Snowy Plover Wilson’s Plover Sandwich Tern Common Tern Least Tern

A B C D E F G H I J K L M N O P Q R

14 adults 7 adults 10 adults 4 with young 0 0 0 0 0 0 0 0 0 0 0 8 adults 0 1 adult 6 adults

1 adult 0 8-10 adults 0 0 0 0 0 0 0 0 0 2 adults 0 0 2 adults 1 adult 8 adults

4 adults 0 0 0 0 0 0 2 adults 0 0 0 0 0 0 5 adults 4 nests 0 0 0

6 adults 18 adults 7 fledglings 3-4 nests 1-2 adults 0 0 0 0 0 2 adults 0 0 2 adults 0 12 adults 0 4 adults 0 0

22 adults 187 adults 49 fledglings 29 nests 30 adults 2+ nests 6 adults 1 nest 31 adults 0 0 8 adults 6 adults 0 0 49 adults 27 nests 0 0 2 adults 0 0 16 adults 6 nests

Table 1. Summary of adults, young, and nests of plovers and terns found during surveys for terns and plovers on Bonaire, Netherlands Antilles, in July 2001. Survey sites are illustrated in Fig. 1.



16-18 on mainland Bonaire and eight on Klein Bon-aire (Fig. 1, Table 1). We found a concentration of 8-10 adults near the salinas on the north side of Lac Bay (Fig. 1–Site C), and six were together at a site on Klein Bonaire (Fig. 1–Site R), though none of these showed any evidence of breeding. Otherwise, birds were seen in pairs or singly. One chick was noted at Lac Bay and several of the pairs at that site were agitated, as though they had eggs or young nearby. One pair near Tanki Kalabas on Klein Bon-aire was also agitated by our presence and clearly had eggs or young nearby. ROYAL TERN Although small numbers were seen at various locations throughout the island, we found no direct evidence of nesting and none of the birds showed a complete black cap extending to the base of the upper mandible. Individuals were seen flying by carrying fish at Playa Tam and Klein Bonaire but most sightings involved loafing birds or birds forag-ing offshore. The largest number of individuals was a count of 12 on 4 July near the salinas along the north side of Lac Bay. We did not observe any juve-nile birds. SANDWICH TERN Sandwich Terns were observed at three locations with confirmed nesting at one location (Fig. 1, Ta-ble 1). Of 11 individuals observed, all but one were of the yellow-billed “Cayenne” form. Four individu-als were noted on 5 July sitting on nests on a small unnamed island in the Lake Goto (Fig. 1–Site O). Four individuals were loafing on 4 July along the western side of the Pekelmeer (Fig. 1–Site A). Two individuals flew by Malmok, Washington-Slagbaai National Park (Fig. 1–Site H) on 6 July, one of which was of the black-billed form. COMMON TERN Foraging and loafing birds were seen at as many as ten locations around the island but breeding was confirmed at only one location (Fig. 1, Table 1). We tallied a minimum of 48 adults, seven fledglings, and at least 3-4 nests. At many of the locations, we observed only 1-2 birds, but 12 foraging birds were seen at Playa Tam (Fig. 1–Site N), and six loafing birds were seen along the west side of the Pekel-meer (Fig. 1–Site A). At the single confirmed nest-ing location along the east side of the Pekelmeer, we counted 18 adults, of which 3-4 were on nests, and seven fledglings (Fig. 1–Site B).

LEAST TERN Least Terns were the most abundant breeding tern on the island. We tallied a minimum of 360 adults at 13 sites, 62 fledglings, and at least 73 nests (Fig. 1, Table 1). Nests were confirmed at 10 of the 13 sites that had concentrations of Least Terns. Because we tried to limit disturbance, especially as temperatures increased, our estimates of the number of nests are certainly lower than the actual number. There were also likely more colonies along sections of the coast that we were not able to survey and within the inte-rior portions of the Pekelmeer, which are part of the commercial salt operations on the island. Largest concentrations of birds and nests were along the eastern side of the Pekelmeer (Fig. 1–Site B), on an island at Boca Slagbaai (Fig. 1–Site L), near Boca Onima (Fig. 1–Site E), and near Lac Bay (Fig. 1–Site C). The high number of fledglings indicates that many of the birds had already completed breed-ing and had been successful.

DISCUSSION Schreiber (2000) presented estimates of numbers of pairs of various species of seabirds breeding in the Caribbean including four of the species we sur-veyed—Royal Tern, Common Tern, Sandwich “Cayenne” Tern, and Least Tern. Though the esti-mates do not include numbers from Bonaire, Cura-çao, or Aruba, or the nearby Venezuelan island bird colonies, they do provide a gauge for the signifi-cance of the numbers from our surveys on Bonaire. For example, Common Terns occur as breeders in the Caribbean in only small numbers (Buckley and Buckley 2000) making even the relatively small colony we documented on Bonaire of conservation significance. Similarly, the total Caribbean breeding population of Least Terns has been estimated at 1500-3000 pairs (Jackson 2000) suggesting that the 180 pairs on Bonaire are a significant regional population, especially as this breeding location is at the species southern range limit, i.e., there are no breeding records from mainland South America (Hilty 2003). The numbers of Least Terns we docu-mented on Bonaire are also within the range esti-mated to breed on Aruba (100-200 pairs) from sev-eral anecdotal observations (Jackson 2000) but sig-nificantly less than numbers documented on Bon-aire and Curaçao in 2002 (A. Debrot pers. comm.). The numbers of “Cayenne” Terns that we docu-mented on Bonaire are much lower than the hun-dreds or thousands (estimated 3-4,000 pairs) that nested intermittently at various sites on Bonaire from the 1960s through at least the early 1980s



(Voous 1983). Common Terns have apparently al-ways bred in relatively small numbers on Bonaire with 10-15 pairs estimated in 1961 (Voous 1965). Royal Terns likewise have historically been known to breed irregularly in very small numbers on Bon-aire (Voous 1983). The number of Least Terns that we documented on Bonaire is much lower than that indicated as occurring prior to the early 1980s by Voous (1983), who wrote that “…the total number [on Aruba + Curaçao + Bonaire] in some years may be close to one thousand pairs, the majority of which on Bonaire.” However, surveys completed in 2002 indicated as many as 800 pairs on Bonaire that year (A. Debrot pers. comm.). We did not observe any Roseate Terns (Sterna dougallii), a species mentioned by Voous (1983) as a former breeder on Bonaire. While the numbers of “Cayenne” Terns and Least Terns may have declined as compared to pre-1980 estimates, we do note the possibility that the sea-birds nesting on Bonaire may be part of a meta-population that could shift breeding sites from among a set of islands including (W to E) Aruba, Curaçao, Bonaire, and the Venezuelan islands of Las Aves, Los Roques, and La Orchila. Unfortu-nately, such major shifts in breeding sites would likely be attributable to major nest predation events that trigger the colony to seek a new, safer location to breed. Predators on any of these islands could include rats and cats that are known to occur at some sites. At many locations, humans may still be taking eggs to sell for food as well. Ideally surveys of all tern nesting areas within the south Caribbean area should be carried out within the same season and over several years to assess whether birds here do indeed represent a metapopulation, the degree of movement of population segments among locations across years, and the overall number of breeding terns in the region. Less information is available on the status of the two plover species so it is more difficult to place our survey information in context. There are no estimates available for total population size of the cinnamominus subspecies of Wilson’s Plover (Wetlands International 2002), the subspecies that breeds along the northern coast of South America and nearby islands including Bonaire, nor are there any estimates of numbers on Bonaire, Curaçao, or Aruba (Voous 1983). Published estimates of total population size of the Snowy Plover population that breeds in the eastern USA, eastern Mexico, and the Caribbean put the total number of birds at 2 200 to 2 800 (Wetlands International 2002). Based on this

estimate, the number of Snowy Plovers breeding on Bonaire would approach 2% of this population and would suggest that the island supports a regionally important breeding concentration. The numbers on Bonaire are further interesting and potentially sig-nificant given that Snowy Plovers have not been confirmed as breeders on the coast of Central Amer-ica (Page et al. 1995), northern South America (Hilty 2003), or in the Lesser Antilles (Raffaelle et

al. 1998). Bonaire and the nearby islands of Aruba, Cura-çao, Las Aves, Los Roques, and La Orchila have the potential to be very important tern and plover breed-ing locations in a regional and global context. Bon-aire, because of its strong natural resource-based ecotourism economy and its history of park designa-tion and natural resource stewardship, is especially well suited to implementing a tern and plover con-servation strategy that could increase the numbers and productivity of breeding terns and plovers. In the USA, many seabird and plover conservation and management techniques have been developed and effectively implemented to increase, stabilize, or restore populations. Some of these techniques could certainly be employed on Bonaire to the benefit of tern and plover populations. In particular, we would recommend that Klein Bonaire be considered as a location to attempt to establish a protected tern col-ony using decoys, calls, and other social attraction methods (Kress 1998) ideally after ensuring that the island, now owned and managed by the National Marine Park, is rid of any invasive rats or cats.

ACKNOWLEDGMENTS We extend our thanks to the Buddy Dive Resort

and Carol Bradovchak for lodging and their friendly assistance during our stay on Bonaire. We are grate-ful to the staff of the Washington-Slagbaai National Park, especially Fernando Simal and George Thode, for access to the park, and to Catriona Glendinning of the Marine Park for arranging transportation and permission to access Klein Bonaire. We also wish to thank the CARMABI institute, particularly Al De-brot and Leon Pors, for assistance in mapping our surveys, and to Tineke Prins and an anonymous reviewer for comments that greatly improved the manuscript. Also, thank you to local birder Jerry Ligon for ongoing discussions about the birds of Bonaire.

LITERATURE CITED

AMERICAN ORNITHOLOGISTS’ UNION. 1998. Check-list of North American birds. 7th edition. Ameri-



can Ornithologists’ Union, Washington, D.C. 829 pp.

BUCKLEY, P. A., AND F. G. BUCKLEY. 2000. Breed-ing Common Terns in Greater West Indies: status and conservation priorities. Pp. 96-102 in Status and conservation of West Indian seabirds (E. A. Schreiber and D. S. Lee, eds.). Society of Carib-bean Ornithology, Special Publication No. 1.

HILTY, S. L. 2003. Birds of Venezuela. Princeton University Press, Princeton. 878 pp.

JACKSON, J. 2000. Distribution, population changes and threats to Least Terns in the Caribbean and adjacent waters of the Atlantic and Gulf of Mex-ico. Pp. 109-117 in Status and conservation of West Indian seabirds (E. A. Schreiber and D. S. Lee, eds.). Society of Caribbean Ornithology, Special Publication No. 1.

KRESS, S. 1998. Applying research for effective management: case studies in seabird restoration. Pp. 141-154 in Avian conservation (J. M. Marzluff and R. Sallabanks, eds.). Island Press, Washington, DC.

PAGE, G. W., J. S. WARRINER, J. C. WARRINER, AND P. W. C. PATON. 1995. Snowy Plover (Charadrius alexandrinus). In The birds of North America, no. 154 (A. Poole and F. Gill, eds.).

Academy of Natural Sciences, Philadelphia, PA, and American Ornithologists’ Union, Washing-ton, D.C.

RAFFAELE, H., J. WILEY, O. GARRIDO, A. KEITH, AND J. RAFFAELE. 1998. A guide to the birds of the West Indies. Princeton University Press, Princeton, NJ. 511 pp.

SCHREIBER, E. A., AND D. S. LEE (eds.). 2000. Status and conservation of West Indian seabirds. Society of Caribbean Ornithology, Special Publi-cation No. 1.

SCHREIBER, E. A.. 2000. Action plan for conserva-tion of West Indian seabirds. Pp. 182-191 in Status and conservation of West Indian seabirds (E. A. Schreiber and D. S. Lee, eds). Society of Caribbean Ornithology, Special Publication No. 1.

VOOUS, K. H. 1965. Nesting and nest sites of Com-mon Tern and Dougall’s Tern in the Netherlands Antilles. Ibis 107:430-431. (Abstract)

VOOUS, K. H. 1983. Birds of the Netherlands Antil-les. de Walburg Pers, Utrecht. 327 pp.

WETLANDS INTERNATIONAL. 2002. Waterbird popu-lation estimates. 3rd ed.. Wetlands International Global Series No. 12, Wageningen, The Nether-lands.



ENDANGERED PIPING PLOVERS (CHARADRIUS MELODUS) OVERWINTERING IN PUERTO RICO

ALLEN R. LEWIS1,5, ADRIANNE G. TOSSAS2, JOSÉ A. COLÓN3, AND BEATRIZ HERNÁNDEZ4

1Department of Biology, University of Puerto Rico, Mayagüez, PR 00681-9012; e-mail: [email protected];

2Department of Biology, University of Puerto Rico, Mayagüez, PR 00681-9012; e-mail: [email protected];

3PO Box 1656, Ciales, PR 00638-1656; e-mail: [email protected]; 4Pedro Cintrón 57, UTT, San Juan,

PR 00926; e-mail: [email protected] Abstract: The Puerto Rican Shorebird Network conducted monthly counts at 14 census sites from 2001-2003. Pip-ing plovers (Charadrius melodus) were found overwintering in restricted locations at three of the sites for multiple years and one was seen once at a fourth site. The number of birds wintering at these locations may be as few as five. Although birds were unmarked, their reappearance at particular sites in successive years suggests site fidelity. Two of the sites are beaches under pressure for development, which may reduce their suitability as wintering areas. Unde-tected Piping Plovers may winter sparsely throughout the Caribbean. Key words: Charadrius melodius, endangered species, migratory shorebird, overwintering, Piping Plover, Puerto Rico Resumen: CHORLO MELÓDICO (CHARADRIUS MELODIUS) UNA ESPECIE EN PELIGRO INVERNANDO EN PUERTO RICO. La Red Limícola Puertorriqueña llevó a cabo conteos mensuales en 14 sitios de censo desde 2001 hasta 2003. Se encontraron Chorlos Melódicos (Charadrius melodus) invernando en lugares específicos en tres de los sitios por múltiples años y uno fue visto una sola vez en un cuarto sitio. El número de aves invernando en estos lugares puede ser tan bajo como cinco. Aunque las aves no estaban marcadas, su reaparición en lugares específicos en años suce-sivos sugiere fidelidad al sitio. Dos de los sitios son playas bajo presión de desarrollo, lo que puede reducir su con-veniencia para la invernación. Chorlos Melódicos podrían estar invernando en bajas densidades a lo largo del Caribe sin ser detectados. Palabras clave: Charadrius melodus, Chorlo Melódico, especie en peligro, invernando, playero migratorio, Puerto Rico Résumé : LE PLUVIER SIFFLEUR (CHARADRIUS MELODUS), ESPECE EN DANGER, HIVERNANTE A PORTO RICO. Le réseau portoricain des limicoles a conduit des comptages mensuels de 2001 à 2003 sur 14 sites. Le Plumier siffleur (Charadrius melodus) a été trouvé en hivernage à des endroits isolés de trois des sites plusieurs années et une obser-vation isolé d’un individu est connue d’un quatrième site. Le nombre d’oiseaux hivernant pourrait être de seulement 5. Bien que les oiseaux n’aient pas été marqués, leur réapparition des années successives aux mêmes localisations isolées suggère une fidélité de site. Deux de ces localisations sont des plages menacées par le développement, et qui pourraient voir leur qualité de site d’hivernage réduite. D’autres Pluviers siffleurs non détectés pourraient hiverner de manière éparse ailleurs dans la Caraïbe Mots-clés : Charadrius melodus, espèce en danger, limicole migrateur, hivernage, Pluvier siffleur, Porto Rico

THE PIPING PLOVER (Charadrius melodus) is an endemic North American shorebird listed as endan-gered in both the United States and Canada (U. S. Fish and Wildlife Service 1985, COSEWIC 2005). Of the 50 species of shorebird nesting in North America it is one of five assigned highest priority in the U. S. Shorebird Conservation Plan (Brown et al. 2001). The distribution and status of the species is relatively well known due to the International Pip-ing Plover Census (IPPC) carried out for winter and breeding populations in 1991, 1996, and 2001 by U. S. and Canadian researchers (Haig et al. 2005). Pip-ing Plovers breed along the shores of lakes and riv-ers of the northern Great Plains in the U. S. and

Canada, along the barrier beaches of the Atlantic seaboard from Newfoundland to North Carolina, and in very small numbers around the Great Lakes. They overwinter along the sandy beaches of the southeastern U. S., the Gulf of Mexico, Cuba, Baha-mas, and in small numbers at other Caribbean loca-tions (Haig and Elliot-Smith 2004, Haig et al. 2005, Raffaele et al. 1998). One of the findings of the species census is that the winter distribution remains incompletely de-fined. The 2001 IPPC found in winter only half as many birds as were found during the breeding sea-son (2 389 vs 5 945; Haig et al. 2005, Ferland and Haig 2002). We speculate that some of the missing



birds are spread thinly over the many km of beach in the Caribbean where few observers are available to record them. Censuses undertaken for the 2001 IPPC found 55 Piping Plovers in Cuba and 35 in the Bahamas, but none in Puerto Rico. Piping Plovers have been reported from Puerto Rico as rare winter visitors (Raffaele 1989, Collazo et al. 1995), and sightings from two Christmas Bird Counts were used justifiably in the IPPC report as evidence of the presence of the species. Nevertheless, little is known about the regular use of Puerto Rico as a wintering site by this species. This note describes Piping Plovers overwintering at low density at three Puerto Rican Shorebird Network survey sites.

METHODS

The Puerto Rican Shorebird Network (PRSN) of the Puerto Rican Ornithological Society initiated monitoring of shorebirds at selected sites in 2001 as part of the International Shorebird Survey organized by the Manomet Center for Conservation Sciences. The network has grown to include 14 sites with a total transect length of 33 km distributed around the coast of Puerto Rico (Fig. 1) in a variety of habitats. Monthly censuses have been taken at most of the sites for up to three calendar years, equivalent to parts of four consecutive winter seasons. Censuses for each area are under the charge of a trained vol-unteer who retraces the same route each month and makes total counts of all species of shorebirds ob-served.

RESULTS At each of three PRSN survey locations (Cabo Rojo salt flats, Isabela, and Luquillo) Piping Plovers have been observed throughout the winter for two to four winter seasons (Table 1). A single sighting was recorded at a fourth survey site, Jobos, in January 2003. The total number of plovers using these sites may be as few as five, with one or two individuals at each site. The Cabo Rojo salt flats (Caribbean Islands Na-tional Wildlife Refuge) supported occasional Piping Plovers from 1985 to 1992 (Collazo et al. 1995). The site contained two Piping Plovers in the four consecutive seasons covered by our surveys (Table 1). The plovers inhabited low-energy sand beaches (little or no wave action), fields of coral rubble, and salt flat at the edge of a shallow, high salinity la-goon. Associated species of shorebirds included resident Snowy Plovers (Charadrius alexandrinus), Wilson’s Plovers (Charadrius wilsonia), and a vari-ety of migratory calidrids. The Luquillo site contained one Piping Plover in seasons two and four (Table 1). The plover inhab-ited high energy beach (heavy wave action) that was protected at some locations by a low strip of lithified sand dune (aeolinite). A band of vegetation separated the beach from adjacent upland areas. Associated species of shorebirds included Semipal-mated Plovers (Charadrius semipalmatus), Black-bellied Plovers (Pluvialis squatarola), Sanderlings (Calidris alba), and Least Sandpipers (Calidris

Fig. 1. Shorebird survey sites in Puerto Rico. Ellipses denote four sites where at least one Piping Plover was found during winter. Bullets denote four additional sites where the ocean beach or protected flat resembled utilized sites but no Piping Plovers were detected. The remaining sites were marsh, lagoon, and mangrove habitats where Piping Plovers were neither observed nor expected. City of San Juan is shown by a circle.

LEWIS ET AL. — CHARADRIUS MELODUS OVERWINTERING IN PUERTO RICO


minutilla). The location used by the plovers is an empty stretch of beach, not the intensively devel-oped recreation area, but it is not a refuge. Con-struction of a resort is under review for the site. The Isabela site contained one and occasionally two Piping Plovers in seasons two, three, and four (Table 1). The site was not examined in season one. When two plovers were found, they were always near each other and foraged together. In all three seasons one or two plovers were usually found rest-ing in a low hollow on the landward side of an aeo-linite outcrop that offered protection from heavy Atlantic surf and wind. Small lagoons lapped the landward side of the aeolinite and supported an al-gal lawn on the lowest aeolinite exposures in which the plovers fed at low tide. The plovers also foraged in the adjacent dry beach sand, and two birds, per-haps the same pair, were once found in dry sand 3 km from the usual site. Associated species of shore-birds included Wilson’s Plovers, Semipalmated Plovers, Black-bellied Plovers, Sanderlings, and Least Sandpipers. All sheltered on the aeolinite and foraged in the algal lawns as well as in wet areas formed higher on the rock by overwash. This site is on a 3 km stretch of beach that has been relatively inaccessible and has no human habitation. However, the beach is not part of a refuge and has recently come under heavy pressure for development.

DISCUSSION Piping Plovers have been in residence at the same

locations for months during consecutive winter sea-sons at Cabo Rojo and Isabela and less consistently at Luquillo. We have not seen evidence that these home ranges are defended, but the reuse of particu-lar sites leads us to speculate that the same individu-als are returning to the same wintering locations. Strong site fidelity within a season has been re-ported for Piping Plovers wintering in Texas (Drake et al. 2001), and between year nest-site fidelity is well known in this species (Wilcox 1959, Haig and Oring 1988). We conclude that Puerto Rico is part of the regular wintering range for this species. The sites used in Puerto Rico are beaches at the opposite ends of the spectrum of wave energy. This suggests that many locations in the Caribbean, in-cluding unstudied sites in Puerto Rico, might be appropriate overwintering sites for Piping Plovers. Unfortunately our census sites were not selected to be a representative sample of coastal habitats; they are sites known to have shorebirds, and they are convenient to reach for particular volunteers. There-fore, we cannot construct a defensible estimate of the total number of Piping Plovers overwintering in Puerto Rico. However, based on a total shoreline of 1,094 km (Earth Trends Country Profiles 2003), five birds in the 33 km census route, and recogni-tion that much of the shoreline of the island is far too developed to sustain the plovers, we can guess that the number is less than 50. The three beaches in Puerto Rico now known as over-wintering sites, as well as the Jobos Reserve where a single bird was

Location Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Cabo Rojo Isabela Luquillo Jobos

2001 2002 2003 2001 2002 2003 2001 2002 2003 2001 2002 2003

1 2 2 – 1 1 0 – 0 – 0 1

1 2 1 – 0 1 0 1 0 – 0 0

1 2 1 – 0 0 0 0 0 – 0 0

0 2 0 – 0 0 0 0 0 – 0 0

0 0 0 – 0 0 0 0 0 – 0 0

0 0 0 – – – 0 0 0 – 0 0

0 0 0 – – – 0 – 0 – 0 0

0 0 0 – 0 0 0 0 0 – 0 0

1 0 0 – 0 0 1 – 0 – 0 0

0 0 0 – 2 0 1 0 1 – 0 0

2 0 1 – 1 1 0 0 0 0 0 0

2 1 0 – 1 2 0 0 0 0 0 0

Table 1. Piping Plover sightings in Puerto Rico by month, year, and location. No Piping Plovers were de-tected in months indicated with a zero; no census was carried out in months indicated with a dash. The table depicts three calendar years per site and, consequently, at least part of four winter seasons.



observed, are characterized by relatively long stretches without development. Such beaches are disappearing from the island. The other four census sites (marked by bullets in Fig. 1) that are either salt flat or beach do not shelter the plovers. These sites have more development with nearby houses and dogs. Less intensively developed sections of Cuba, Hispaniola, and the Bahamas may have more birds. Some of the Piping Plovers missing from the 2001 IPPC winter census may be scattered over thou-sands of km of coastline in the Caribbean and the Bahamas. As construction-based economic development transforms beaches that are not part of any refuge system, the suitability of the beaches for the plovers may decline, and because of their strong site fidelity the plovers may be unable to respond flexibly. Car-ibbean beaches are everywhere under pressure. Continuous monitoring is essential to detect and understand changes in use of wintering grounds by the birds in response to the intensification of use of the sites by people, and we hope the results of this study will encourage others in the Caribbean to carry out similar efforts. The Caribbean emphasis in the 2006 winter census (S. Haig pers. comm.) may also spur additional interest in this important region.

ACKNOWLEDGMENTS We express our appreciation to our colleagues in the Puerto Rico Shorebird Network who have car-ried out monthly censes for the past 3 yr. Partici-pants include Sergio Colón, Cosme Lantigua, Luis Muñiz, Alberto Puente, José E. Rodríguez, Rafael Rodríguez, José Salguero, and José Sepúlveda. Their careful efforts have increased our understan-ding of patterns of movement of shorebirds through Puerto Rico. We also wish to recognize the efforts of the Manomet Center for Conservation Sciences for their organization and promotion of the Interna-tional Shorebird Surveys and to thank the U. S. Fish and Wildlife Service for logistic support.

LITERATURE CITED BROWN, S., C. HICKEY, B. HARRINGTON, AND R.

GILL (eds.). 2001. The U. S. shorebird conserva-tion plan. 2nd ed. Manomet Center for Conserva-tion Sciences, Manomet, MA.

COLLAZO, J. A., B. A. HARRINGTON, J. S. GREAR, AND J. A. COLÓN. 1995. Abundance and distribu-tion of shorebirds at the Cabo Rojo Salt Flats, Puerto Rico. Journal of Field Ornithology 66:424-438.

COSEWIC. 2005. Canadian species at risk. Com-mittee on the Status of Endangered Wildlife in Canada. Http://www.cosewic.gc.ca/eng/sct0/rpt/rpt_csar_e.cfm

DRAKE, K. R., J. E. THOMPSON, K. L. DRAKE, AND C. ZONICK. 2001. Movements, habitat use, and survival of nonbreeding Piping Plovers. Condor 103:259-267.

EARTH TRENDS COUNTRY PROFILES. 2003. Coastal and marine ecosystems: Puerto Rico. Http://earthtrends.wri.org/pdf_library/country_profiles/coa_cou_630.pdf

FERLAND, C. L., AND S. M. HAIG. 2002. 2001 Inter-national Piping Plover census. U. S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR. 293 pp.

HAIG, S. M., AND E. ELLIOTT-SMITH. 2004. Piping Plover. The birds of North America Online (A. Poole, ed.) Cornell Laboratory of Ornithology, Ithaca, NY. Http://bna.birds.cornell.edu/BNA/account/Piping_Plover.

HAIG, S. M., C. L. FERLAND, F. J. CUTHBERTY, J. DINGLEDINE, J. P. GOOSSEN, A. HECHT, AND N. MCPHILLIPS. 2005. A complete species census and evidence for regional declines in Piping Plov-ers. Journal of Wildlife Management 69:160-173.

HAIG, S. M. AND L. W. ORING. 1988. Mate, site, and territory fidelity in Piping Plovers. Auk 105:268-277.

RAFFAELE, H. A. 1989. A guide to the birds of Puerto Rico and the Virgin Islands. Princeton University Press, Princeton, NJ.

RAFFAELE, H. A., J. WILEY, O. GARRIDO, A. KEITH, AND J. RAFFAELE. 1998. A Guide to the birds of the West Indies. Princeton University Press, Princeton, NJ.

U. S. FISH AND WILDLIFE SERVICE. 1985. Determi-nation of endangered and threatened status for Piping Plover. Federal Register 50:50726-50734. Http://www.fws.gov/endangered/wildlife.html

WILCOX, L. 1959. A twenty year banding study of the Piping Plover. Auk 76:129-152.



FIVE NEW SPECIES OF BIRDS FOR ARUBA, WITH NOTES ON OTHER SIGNIFICANT SIGHTINGS

STEVEN G. MLODIINOW

4819 Gardner Avenue, Everett, WA 98203, USA; e-mail: [email protected]

Abstract: A trip to Aruba during mid-March 2005 produced five previously unrecorded species: Great Frigatebird (Fregata minor), Ring-necked Duck (Aythya collaris), Greater Ani (Crotophaga major), Red-eyed Vireo (Vireo

olivaceus), and Indigo Bunting (Passerina cyanea). Three other species were recorded only once previously. These species were from a diverse set of families and widely differing geographical origins. Also found were a number of passerines generally considered rare to casual in the southern Caribbean Basin. Aruba’s apparent attraction for such vagrants is not clear but may be related to its relatively westerly position and its scarce but easily accessible habitat increasing the observer’s ability to find such birds.

Key words: Aruba, Aythya collaris, Crotophaga major, distributional records, Fregata minor, new bird species, Passerina cyanea, Vireo olivaceus Resumen: CINCO NUEVAS ESPECIES PARA ARUBA Y NOTAS SOBRE OTROS AVISTAMIENTOS SIGNIFICATIVOS. Una expedición a Aruba a mediados de marzo del 2005 produjo cinco nuevos registros de especies: Fregata Grande (Fregata minor), Pato Cabezón (Aythya collaris), Greater Ani (Crotophaga major), Vireo de Ojo Rojo (Vireo oliva-

ceus), y el Azulejo (Passerina cyanea). Otras tres especies habían sido reportadas solo una vez con anterioridad. Estas especies pertenecen a un grupo diverso de familias y de muy diferentes orígenes geográficos. También se en-contró un cierto número de paserinas consideradas generalmente raras o casuales en el sur del Caribe. El atractivo aparente de Aruba para estos vagrants no está claro pero puede estar relacionado a su posición relativamente occi-dental y a sus dispersos, pero accesibles hábitats, que aumentan la probabilidad de los observadores de encontrar estas aves. Palabras clave: Aruba, Aythya collaris, Crotophaga major, especies de aves nuevas, Fregata minor, nuevos re-portes de especies, Passerina cyanea, reportes de distribución, Vireo olivaceus

Résumé : CINQ NOUVELLES ESPECES POUR ARUBA, AVEC DES NOTES SUR D’AUTRES OBSERVATIONS INTERESSAN-

TES. Un voyage à Aruba mi mars 2005 a permis d’observer 5 espèces nouvelles : la Frégate du Pacifique (Fregata

minor), le Fuligule à collier (Aythya collaris), l’Ani des palétuviers (Crotophaga major), le Viréo aux yeux rouges (Vireo olivaceus), et le Passerin indigo (Passerina cyanea). 3 autres espèces observées n’avaient été vues qu’une seule fois auparavant. Ces espèces étaient de diverses familles et d’origines géographiques très variées. D’autres espèces rares ou accidentelles dans le sud du bassin caraïbe ont aussi été notées. L’apparente attraction d’Aruba pour de tels erratiques n’est pas claire mais pourrait être liée à sa localisation relativement à l’ouest et par son habitat rare mais facilement accessible qui augmente les chances pour l’observateur de trouver de tels oiseaux. Mots-clés : Aruba, Aythya collaris, Crotophaga major, distribution des observations, Fregata minor, nouvelles espèces d’oiseaux, Passerina cyanea, Vireo olivaceus

CASEY BEACHELL AND I explored Aruba from 12 to 18 March 2005, our third such visit. During this time, we repeatedly visited the Bubali Bird Sanctu-ary, Tierra del Sol Golf Course, Spanish Lagoon, and flooded saltflats near Malmok, discovering five species of birds previously unrecorded from Aruba plus three species detected only once previously. The Bubali Bird Sanctuary and the lake at Tierra del Sol Golf Course provide the only significant perma-nent freshwater habitat on this arid island. Bubali was created in 1972 to handle sewage outflow from the island’s resorts and hotels. The resultant marsh is about 1 km long and 0.5 km wide, with most of the area covered by cattails (Typha spp.) and water lettuce (Pistia stratiotes). On the marsh’s west

shore, there is a line of broadleaf trees with a can-opy ranging mostly from 3-6 m in height. The golf course lake is Y-shaped and, when full, about 1 km long and 0.25 km wide. This lake provides muddy and grassy edges as well as a strip of Typha marsh. Presumably the level of the lake is dependent on run-off from the golf course and precipitation. Spanish Lagoon is a brackish 1 km cut into the is-land’s interior and is the most prominent mangrove swamp on Aruba. Finally, towards the north side of the island, there is a series of saltpans that have wa-ter only if there has been sufficient recent rainfall, and Aruba’s rainfall from September 2004 through January 2005 was substantially above normal Aruba (Meteorological Service Netherland Antilles and



Aruba 2004, 2005). During March 2005, almost all contained water fringed by muddy shoreline, but only the saltpan near Malmok was used regularly by shorebirds. Full descriptions of all birds reported herein are on file at the Zoological Museum of the University of Amsterdam.

FIRST RECORDS

GREAT FRIGATEBIRD (FREGATA MINOR) On 15 March 2005 an adult female Great Frigate-bird was seen at Ceroe Colorado, the southeast cape of the island. It was observed for 4-5 min as close as 50 m. The shape of the belly patch, complete dark chest band, and limited white on axillars eliminated other frigatebird species (James 2004, D. J. James, in litt). Great Frigatebird has not been previously recorded on the Aruba, Bonaire, or Curaçao (the ABC Islands), Venezuela, Trinidad and Tobago or the West Indies (Voous 1983, ffrench 1991, Hilty 2003). The Atlantic Ocean breeding population is limited to Trinidade Island and Martin Vas Rocks off Brazil (American Ornithologists’ Union 1998). In the North Pacific, Great Frigatebirds breed as far north as Mexico’s Islas Revillagigedo (Howell and Webb 1995) and have wandered as far north as the Farallon Islands, California (Richardson et al. 2003). Great Frigatebird has also been recorded once in the eastern United States in Oklahoma (Tomer et al. 1996). RING-NECKED DUCK (AYTHYA COLLARIS) On three occasions from 12-16 March 2005 we were able to study, at length, two female Ring-necked Ducks at the Tierra del Sol Golf Course. The distinctive head shape, bill pattern, and diag-nostic facial pattern were easily seen. This species winters regularly as far south as the Virgin Islands, but in the Lesser Antilles it is found less than once per decade (Raffaele et al. 1998), and there are but three records from Venezuela (Hilty 2003). Reuter and Prins (in prep.) list three records from Curaçao, including eight together during 1999, and one from Bonaire. There have been several records from Trinidad and Tobago (e.g., ffrench 1991, Hayes and White 2000, White and Hayes 2002). GREATER ANI (CROTOPHAGA MAJOR) Near noon on 13 March 2005 at Spanish Lagoon we observed two large birds that landed above us giving a croak-like call. They were large, glossy black, and had exceptionally long tails. We watched the birds from about 10 m for 2-3 min before they

flew off. The distinctive bill shape and white eyes were readily apparent. Greater Ani had not previ-ously been recorded on the ABC Islands nor the West Indies (Raffaele et al. 1998, Reuter and Prins, in prep.). In northern Venezuela, where fairly com-mon from late April to November, they occur mostly as migrants from Amazonia but are also found in smaller numbers during the remainder of the year (Hilty 2003). Greater Anis are a fairly com-mon resident in Trinidad and Tobago, where they inhabit mangrove swamps among other habitats (ffrench 1991). RED-EYED VIREO (VIREO OLIVACEUS) At Spanish Lagoon on 13 March 2005, we watched a vireo for approximately 4 min, observing the lack of a dusky “whisker” mark, bright red eyes, relatively bright green back, and strong facial pat-tern. Black-whiskered Vireo (V. altiloquus) was eliminated by the lack of a “whisker,” the relatively bright green back, the stronger facial pattern, and the relatively smaller bill. Yellow-green Vireo (V.

flavoviridis) would have had a larger bill, been more brightly colored, and lacked the dark upper border to the supercilium. It is surprising that this species had not been previously detected on Aruba, as mi-grant Red-eyed Vireos from North America are uncommon to fairly common in Venezuela (Hilty 2003), and there are at least six records from Bon-aire and three from Curaçao (Voous 1983, Reuter and Prins in prep.). Its similarity to the resident Black-whiskered Vireo may partly explain the lack of previous records. Given this individual’s bright red eyes, it was likely of the nominate North Ameri-can race, rather than one of the South American races which have browner eyes (Hilty 2003). INDIGO BUNTING (PASSERINA CYANEA) A brown Indigo Bunting (likely an immature fe-male) was noted 12 March 2005 in a weedy area bordering the sewage treatment plant at the Bubali Bird Sanctuary. Black-faced Grassquit (Tiaris bi-

color) was easily eliminated by shape and lack of olive hues. The relatively dull brown color and lack of prominent wingbars eliminated Lazuli Bunting (P. amoena), and Blue-black Grassquit (Volatinia

jacarina) would have been smaller with a sharper all black bill. In the West Indies Indigo Buntings are regular as far south as the Virgin Islands and San Andres, though they are rarely recorded in the Lesser Antilles (once in St. Martin, twice in Domin-ica, once in Barbados; McNair et al. 1999, Islam 2002, Brown 2005) and have been recorded but

MLODINOW — NEW OR SIGNIFICANT BIRD RECORDS FOR ARUBA


once in Venezuela and once on Trinidad and To-bago (ffrench 1991, Hilty 2003). Surprisingly, there are multiple records from Bonaire and Curaçao, sometimes involving small flocks, from early No-vember into late April (Voous 1983), and they are currently considered regular on Bonaire and Cura-çao (Reuter and Prins, in prep.). The lack of pre-existing records from Aruba may well be due to relatively poor ornithological coverage.

SECOND RECORDS

LITTLE EGRET (EGRETTA GARZETTA) An individual of this species was observed for 5 min at some distance, but in excellent light, from the observation tower at Bubali early in the morning of 12 March. The dark lores and two long filamen-tous head plumes without shaggy crest were noted. The bird associated with several Snowy Egrets (E.

thula), the yellow lores of which were easily seen. An individual of this species allowed close study at Tierra del Sol Golf Course 25-30 March 2003, pro-viding the ABC Islands’ first record (Mlodinow 2004). This Old World species was first recorded in the Western Hemisphere at Barbados on 16 April 1954 (Bond 1966). Its numbers have increased dra-matically in the Caribbean Basin since the 1980s, with breeding first noted at Barbados in 1994 and over 50 records from Trinidad and Tobago, mostly from January to April (Massiah 1996, Hayes and White 2001, Mlodinow et al. 2004). There are no records for Venezuela (Hilty 2003). The 12 March 2005 bird may well be the same one seen at Tierra del Sol two years earlier. LIMPKIN (ARAMUS GUARAUNA) On the evening of 12 March, we observed a Limpkin for 5-10 min as it stalked the lake’s edge at Tierra del Sol. Eventually, it flew to the marshy portion of the lake, and we were unable to relocate it that day or on further visits. This distinctive bird lacked the white spots on the back typical of A. g.

dolosus from North America, Central America, and the West Indies; rather, the pale streaking was lim-ited to the head and neck, typical of the nominate race from South America. Some local movement occurs in northern Venezuela, where it is most com-mon June to October (Hilty 2003). This species is an uncommon resident on Trinidad and Tobago (ffrench 1991). The only other record for the ABC Islands was from Ceru Colorado, Aruba, in Febru-ary 1975 (Voous 1983, Reuter and Prins, in prep.).

PHILADELPHIA VIREO (VIREO PHILADELPHICUS) Just after sunrise on 18 March, a vireo with a relatively small bill (when compared to Red-eyed or Black-whiskered) and bright yellow throat and chest approached within 3 m at Spanish Lagoon. It lacked wingbars and had a dark transocular stripe, a whit-ish supercilium, and a gray crown. A Tennessee Warbler (Vermivora peregrina) would have had a much finer bill, and would not have had the combi-nation of yellow underparts and blue-gray cap or a bright yellow throat and chest. Red-eyed, Black-whiskered, and Yellow-green Vireo were eliminated by the solidly yellow throat and chest plus the rela-tively small bill. A Brown-capped Vireo (V. leuco-

phrys) would have had a whiter throat, brown cap, and less distinct transocular stripe, while Warbling Vireo (V. gilvus) would also lack the solidly yellow throat and chest and would have had pale lores. Philadelphia Vireo is less than annual in the West Indies and is unrecorded from the Virgin Islands or Lesser Antilles (Raffaele et al. 1998). It has been recorded in South America only in Colombia (American Ornithologists’ Union 1998) and there are two prior ABC Island records, one from Spanish Lagoon on 13 January 2002 (Wells and Wells 2004) and one on Curaçao in April 2000 (Wells and Wells 2001).

ADDITIONAL RECORDS OF NOTE During our stay we also recorded a number of presumably unusual neotropical migrants, including 11 Northern Parulas (Parula americana), three Chestnut-sided Warblers (Dendroica pensylvanica), ten Cape May Warblers, a Black-throated Blue Warbler (D. caerulescens), nine Prothonotary War-blers (Protonotaria citrea), an Ovenbird (Seirus

aurocapillus), a Louisiana Waterthrush (Seiurus

motacilla), 13 Common Yellowthroats (Geothylpis trichas), and a Hooded Warbler (Wilsonia citrina). Prior to 2005, Aruba had two records of Chestnut-sided Warbler, three of Cape May Warbler, three of Black-throated Blue Warbler, twelve of Prothono-tary Warbler, six of Ovenbird, two of Louisiana Waterthrush, and six-plus records of Hooded War-bler (Voous 1983, Reuter and Prins, in prep.). Ob-servations from Bonaire and Curaçao show these vagrants occur at least equally often on these islands (Reuter and Prins, in prep.). Furthermore, Voous (1983) listed only ten ABC Island records of North-ern Parula and one of Common Yellowthroat, al-though both have subsequently been found regularly in small numbers on Aruba (J. Wells in litt,



Mlodinow pers. obs.). We found nine parulas during March 2003 and six during March 2004. Although we did not find any Common Yellowthroats during March 2003, five were detected at Bubali during March 2004. Of the above species, Northern Parula, Chestnut-sided Warbler, Black-throated Blue War-bler, and Common Yellowthroat are considered vagrants in nearby Venezuela, and Cape May War-bler, Ovenbird, Louisiana Waterthrush, and Hooded Warbler are listed as rare there (Hilty 2003). The status of these species is similar on Trinidad and Tobago (ffrench 1991). Only Prothonotary Warbler is uncommon to fairly common in Venezuela and Trinidad and Tobago (Hilty 2003, ffrench 1991). On our previous March trips to Aruba, we had been surprised by the relative abundance of what should be rare-to-accidental neotropical migrants based on these species’ abundance in the Lesser Antilles, Trinidad and Tobago, and Venezuela. This year furnished even more of these “rare” visitors than normal. It is not clear why Aruba (and Bonaire and Curaçao) seemingly attract so many more of these neotropical vagrants than other islands in the southern Caribbean or Venezuela. The relative lack of habitat may simply make it easier for observers to find them, especially when compared to mainland South America. Furthermore, the ABC Islands are located farther west than other southern Caribbean Islands, perhaps increasing the likelihood that spe-cies wintering predominantly in Central America and Mexico may stray there. Of the passerine va-grants noted above, Philadelphia Vireo, Chestnut-sided Warbler, Louisiana Waterthrush, Hooded Warbler, and Indigo Bunting have a predominantly Mexican / Central American winter distribution. Aruba is approximately 850 km west of Grenada, the nearest island in the Lesser Antilles, and 850 km east of Costa Rica, which is at the same latitude in Central America. Furthermore, this year’s success in particular may well have been related to the increased precipitation received from September 2004 through January 2005. During September, mostly related to the pas-sage of Hurricane Ivan to the north, Aruba received 256 mm of rain compared with the long-term aver-age of 35 mm, causing local flooding, a most un-usual event on Aruba (Meteorological Service Neth-erlands Antilles and Aruba 2004). A high level of rainfall persisted through December, with the Octo-ber through December precipitation total being 402 mm, well above the average of 200 mm (Meteorological Service Netherlands Antilles and Aruba 2004). Only in January did the heavy rainfall

begin to abate with 94 mm rather than the typical 62 mm and by February, precipitation levels had re-turned to normal (Meteorological Service Nether-lands Antilles and Aruba 2005). The island was clearly greener during March 2005 than during the previous two years, and the number of dragonflies and butterflies were well above what we’d experi-enced before. With increased precipitation, and ap-parently increased insect abundance, it would be easy to imagine that more fall migrants chose to winter on Aruba rather than move on to the South American mainland. Indeed, the increased storm activity during the fall migratory period may even have led to more birds being deposited on Aruba.

ACKNOWLEDGMENTS I owe a great debt of gratitude to Tineke Prins of the Zoological Museum of the University of Am-sterdam for her steady supply of data and for putting up with my badgering. I also owe her thanks for reviewing and improving this manuscript. Ruud van Halewijn reviewed and significantly improved an earlier version of this manuscript. Francisco Franken of the Department of Fisheries was kind enough to take me out to Aruba’s tern nesting colo-nies, thereby putting me in the right place at the right time to see the Great Frigatebird, and thanks to Castro Perez of the Department of Tourism for ar-ranging the entire matter. The identification of said frigatebird would have been impossible without the help of David James. I also owe thanks to Facundo Franken, Al Debrot, Adam Brown, and Hans Reuter for providing useful information. Finally, and per-haps above all else, thanks to the kind folks of Aruba in general, and those of the Bucuti Beach Resort in particular, for making our visits utterly enjoyable.

LITERATURE CITED AMERICAN ORNITHOLOGISTS’ UNION. 1998. Check-

list of North American birds. 7th ed. Allen Press Inc., Lawrence, KS.

BOND, J. 1966. Eleventh supplement to the Check-list of the birds of the West Indies. Academy of Natural Sciences, Philadelphia, PA.

BROWN, A. C., AND N. COLLIER. 2005. New and rare bird records from St. Martin, West Indies. Cotinga 25:52-58.

FFRENCH, R. 1991. A guide to the birds of Trinidad and Tobago. Cornell University Press, Ithaca, NY.

HAYES, F. E., AND G. WHITE. 2000. First report of the Trinidad and Tobago Rare Bird Committee.



Living World, Journal of the Trinidad and To-bago Field Naturalists’ Club 1999-2000:39-45.

HAYES, F. E., AND G. L. WHITE. 2001. Status of the Little Egret (Egretta garzetta) in Trinidad and Tobago. Pitirre 14:54-58.

HILTY, S. L. 2003. Birds of Venezuela. 2nd ed. Princeton University Press, Princeton, NJ.

HILTY, S. L., AND W. L. BROWN. 1986. A guide to the birds of Colombia. Princeton University Press, Princeton, NJ.

HOWELL, S. N. G., AND S. WEBB. 1995. A guide to the birds of Mexico and Northern Central Amer-ica. Oxford University Press, Oxford.

ISLAM, K. 2002. Second sight record of Indigo Bun-ting (Passerina cyanea) on Dominica. Pitirre 15: 77.

JAMES, D. J. 2004. Identification of Christmas Is-land, Great and Lesser Frigatebirds. Birding Asia 1:22-38.

MASSIAH, E. 1996. Identification of Snowy and Little Egret. Birding World 9:434-444.

MCNAIR, D. B., E. B. MASSIAH, AND M. D. FROST. 1999. New and rare species of Nearctic landbird migrants during autumn for Barbados and the Lesser Antilles. Caribbean Journal of Science 35:46-53.

METEOROLOGICAL SERVICE NETHERLANDS ANTIL-

LES AND ARUBA. 2004. Annual climatological report, 2004. Http://www.meteo.an

METEOROLOGICAL SERVICE NETHERLANDS ANTIL-

LES AND ARUBA. 2005. Climatological survey Aruba, January and February 2005. Http://www.meteo.an

MLODINOW, S. G. 2004. First records of Little Egret, Green-winged Teal, Swallow-tailed Kite,

Tennessee Warbler, and Red-breasted Blackbird from Aruba. North American Birds 57:559-561.

MLODINOW, S. G., W. E. DAVIS, JR., AND J. I. DIES. 2004. Possible anywhere: Little Egret. Birding 36:52-62.

RAFFAELE, H., J. WILEY, O. GARRIDO, A. KEITH, AND J. RAFFAELE. 1998. A guide to the birds of the West Indies. Princeton University Press, Princeton, NJ.

RICHARDSON, T. W., P. PYLE, R. BURNETT, AND P. CAPITOLO. 2003. The occurrence and seasonal distribution of migratory birds on Southeast Far-allon Island, 1968-1999. Western Birds 34:58-96.

REUTER, J. H., AND T. G. PRINS. In prep. Checklist of the birds of Aruba, Curaçao, and Bonaire, Netherlands Antilles.

TOMER, J. S., R. B. CLAPP, AND J. C. HOFFMAN. 1996. Fregata minor, Great Frigatebird, in Okla-homa. Bulletin of the Oklahoma Ornithological Society 29:34-35.

VOOUS, K. H. 1983. Birds of the Netherlands Antil-les. De Walburg Pers, Utrecht, Netherlands.

WELLS, J. V., AND A. M. CHILDS WELLS. 2001. First sight record of Philadelphia Vireo (Vireo

philadelphicus) for Curaçao, Netherlands Antil-les, with notes on other migrant songbirds. Pitirre 14:59-60.

WELLS, J. V., AND A. M. CHILDS WELLS. 2004. Photographic documentation of Philadelphia Vireo on Aruba. North American Birds 57:562-563.

WHITE, G., AND F. E. HAYES. 2002. Second report of the Trinidad and Tobago Rare Bird Commit-tee. Living World, Journal of the Trinidad and Tobago Field Naturalists’ Club 2002:51-56.



ANÁLISIS DE LAS RECUPERACIONES DE EJEMPLARES ANILLADOS DE GARZAS Y COCOS (CICONIIFORMES) EN EL PERIODO DE 1913 A 1998

DENNIS DENIS AVILA Y HECTOR M. SALVAT TORRES

Facultad de Biología, Universidad de La Habana; Calle 25 entre J e I, Vedado, Ciudad Habana, Cuba; email:

[email protected]

Resumen: La técnica de anillamiento y recuperaciones de aves migratorias es uno de los métodos más eficientes para obtener información sobre patrones de movimiento y parámetros demográficos en estas especies. Los miembros del orden Ciconiiformes presentan fuertes procesos dispersivos post-cría que oscurecen los patrones migratorios, sin embargo, se sabe que los humedales cubanos mantienen grandes poblaciones bimodales. El objetivo de este trabajo es analizar las recuperaciones de individuos de Ciconiiformes anillados en Norteamérica y recuperados en Cuba entre 1913 y 1998, a partir de la base de datos del Departamento de Pesca y Fauna de los EEUU (USFWS). En este periodo se recuperaron los anillos de 273 individuos de Ciconiiformes, de ocho especies. El análisis de los recobra-dos por década mostró un comportamiento ascendente en la primera mitad de siglo, con un marcado descenso a par-tir de la década de los 80. Las especies con mayor representación fueron el Guanabá de la Florida (Nycticorax nycti-

corax) y el Coco Prieto (Plegadis falcinellus). Los meses de mayor cantidad de recuperaciones correspondieron a la migración invernal, aunque se presentaron recuperaciones en meses intermedios. Las provincias con mayor número de recobrados fueron La Habana, Pinar del Río y Sancti Spiritus y los individuos provenían mayormente de New Jersey, Virginia y Carolina del Sur. Palabras clave: recuperación, anillamiento, Caribe, garzas, cocos, movimientos Abstract: ANALYSIS OF BANDED BIRD RECOVERIES OF HERONS AND EGRETS (CICONIIFORMES) DURING THE PE-

RIOD 1913 TO 1998. Banding of migratory birds is one of the most efficient tools used in gathering information on movements and demography. Members of the order Ciconiiformes exhibit strong post fledging dispersal movements that confound migrational patterns. The objective of this paper in to analyze recoveries of ciconiiform birds banded in North America and recovered in Cuba from 1913 to 1998, registered in the US Fish and Wildlife Service (USFWS) data base located in Laurel, Maryland. During this period, 273 individuals of eight species of ciconiiform birds were recovered. Numbers per decade demonstrate an increase in the first half of the century, followed by a decrease commencing in the 1980s. The species most represented were Black-crowned Night Heron (Nycticorax

nycticorax) and Glossy Ibis (Plegadis falcinellus). The months with the highest rate of band recovery corresponded to winter migration but there were recoveries outside of the migratory period as well. Provinces with the most recov-eries were La Havana, Pinar del Río, and Sancti Spiritus, and the individuals were banded mostly in New Jersey, Virginia, and South Carolina. Key words: banding, Caribbean, egrets and herons, ibises, movements, recoveries Résumé : ANALYSE DES DONNEES DE BAGUAGE D’ AIGRETTES ET DE HERONS (CICONIIFORMES) ENTRE 1918 ET 1998. L’analyse des données de baguages est l’un des outils les plus efficaces de collecte d’information sur les dé-placements et sur la démographie des oiseaux migrateurs. Les espèces de Ciconiiformes présentent un erratisme juvénile marqué qui complique la compréhension des schémas migratoires. Malgré cela, il est connu que les zones humides de Cuba présentent une distribution des populations nettement bimodale. L’objectif de cet article est d’ana-lyser les données de Ciconiiformes disponibles dans la base de données de l’USFWS bagués en Amérique du Nord, et obtenues à Cuba entre 1913 et 1998. Pendant la période étudiée, 273 individus de 8 espèces de Ciconiiformes ont été enregistrés. Le nombre d’individus par décade montre une augmentation pendant la première moitié du XXème siècle puis une diminution marquée depuis les années 1980. Les espèces les plus représentées sont le Héron bihoreau (Nycticorax nycticorax) et l’Ibis falcinelle (Plegadis falcinellus). Les mois comportant le plus de données correspon-dent à la migration hivernale mais certaines données concernent la période intermédiaire. Les provinces avec le plus de données sont celles de La Havane, Pinar del Rio, et Sancti Spiritus. Les oiseaux avaient été essentiellement ba-gués dans les états du New Jersey, de Virginie, et de Caroline du Sud. Mots-clés : aigrette, baguage, Caraïbe, contrôles, héron, ibis, déplacements, reprises


LA TÉCNICA DE ANILLAMIENTO y recuperaciones de aves acuáticas migratorias ha sido, históricamen-te, uno de los métodos más utilizados para la obten-ción de información acerca de los patrones de movi-

miento y de importantes parámetros demográficos en estas especies (Baillie 1995). Para la conserva-ción de las poblaciones de aves acuáticas se requie-re de una visión transcontinental, ya que es vital que


DENIS AVILA Y SALVAT TORRES — RECOBRADO DE GARZAS Y COCOS EN CUBA

los esfuerzos conservacionistas tengan en cuenta las zonas de residencia estacional de las poblaciones migratorias. Entre las aves acuáticas existe una dis-persión amplia y aleatoria de los juveniles desde los sitios de reproducción. Estos movimientos generales son bien marcados en el orden Ciconiiformes, y se ha pensado que sea un mecanismo utilizado para la colonización de nuevas áreas (Byrd 1978). Ya desde principios del pasado siglo, Townsend (1931) planteaba que las garzas norteamericanas presentan un patrón de migración excepcional, ya que migran hacia el norte después de la estación de cría, por un simple instinto heredado. En Norteamé-rica la dispersión post-nidada ocurre en todas las direcciones pero preferentemente hacia el sur-oeste. Estos movimientos que siguen a la reproducción pueden oscurecer los patrones de migración inver-nal en los Ciconiiformes, que son en su mayoría migratorios, y se mezclan anualmente con poblacio-nes residentes en las islas del Caribe. Numerosos estudios se han centrado en aspectos de la migración y áreas de invernada de estas espe-cies en el continente norteamericano (Coffey 1943, 1948, Dusi 1967, Browder 1973, Byrd 1978, Ryder 1978), sin embargo, en Cuba y otras áreas del Cari-be, se han publicado sólo trabajos puntuales que analizan las recuperaciones en algunos grupos como Anseriformes (Rodríguez 2004, Blanco y Sánchez 2005) o Phoenicopteriformes (Blanco et al. 2003). Byrd (1978) analizó 4 459 recuperaciones de garzas anilladas en el territorio de América del Norte, pero apenas hace referencia al área del Caribe. Mikuska et al. (1998) identificaron en Bahamas y el Caribe

11 sitios de invernada claves para las garzas migra-torias de Norteamérica, cinco de ellos en territorio cubano y para ello utilizaron datos de 851 recupera-ciones de anillos, aunque no brindan detalles especí-ficos en cada área. En Cuba no existen trabajos rela-cionados con este tema para las garzas (Ardeidae) y cocos (Threskiornithidae), aunque es conocido que humedales cubanos contienen grandes poblaciones bimodales de todas estas especies, y constituyen un refugio invernal de importantes cantidades de estas aves (Denis et al. 2003). En este trabajo se presenta un análisis detallado de las recuperaciones de las especies del orden Ci-coniiformes, anilladas en el continente norteameri-cano, entre los años 1913 y 1998. Los resultados aportan nuevos elementos relacionados con la mi-gración de estas aves, que pueden contribuir al desa-rrollo de programas y estrategias futuras dirigidas a la conservación de especies del orden y sus hábitats naturales.

MATERIALES Y MÉTODOS Los registros de recuperaciones de aves anilladas en Cuba se han obtenido históricamente a través de la colaboración de pescadores, cazadores y durante colectas científicas, y han sido recopiladas por el Laboratorio de Aves Migratorias de Cuba, pertene-ciente al Instituto de Ecología y Sistemática del Ministerio de Ciencia, Tecnología y Medio Am-biente. Estos datos se unieron a los enviados por los centros de anillamiento del Servicio de Pesca y Vi-da Silvestre de Estados Unidos (USFWS) y por el Servicio Canadiense de Vida Silvestre (CWS).

Tabla 1. Número y años de recobrados de los individuos por especie, del orden Ciconiiformes, recuperados en Cuba durante el período de 1930 a 1998.

Especie n Mínimo Máximo

Guanabá de la Florida (Nycticorax nycticorax) Garza Ganadera (Bubulcus ibis) Garcilote (Ardea herodias) Garzón (Ardea alba) Garza de Vientre Blanco (Egretta tricolor) Garza de Rizos (Egretta thula) Garza Azul (Egretta caerulea) Coco Blanco (Eudocimus albus) Coco Prieto (Plegadis falcinellus)

76 20 28 36 17 21 13 24 38

1914 1958 1932 1937 1931 1940 1938 1956 1958

1996 1991 1997 1998 1998 1996 1969 1984 1991

Años de Recobrados



RESULTADOS Entre 1913 y 1998 se recuperaron 273 individuos anillados del orden Ciconiiformes en Cuba, pertene-cientes a ocho especies (Tabla 1). El análisis de los recobrados por década mostró un comportamiento ascendente en la primera mitad de siglo, con un descenso a partir de la década de los 80 (Fig. 1). Esta tendencia refleja la importancia del anillamiento, que cobró fuerzas en década de los años 30 impulsado por organizaciones ornitológi-cas. Un comportamiento similar en el tiempo pre-sentaron las recuperaciones del orden Anseriformes, según mencionan Blanco y Sánchez (2005). La distribución espacial de las recuperaciones ha incluido todas las provincias de Cuba en proporcio-nes relacionadas a la extensión de su territorio y al área de humedales (Tabla 2). Las provincias con

mayor cantidad de recobrados son La Habana, Sancti Spíritus y Pinar del Río, mientras que Ciudad de la Habana fue donde menor cantidad de recobra-dos hubo. El número de recapturados para las tres provincias con mayor incidencia es de 119 para un 43,6 % del total. El bajo número de recapturas en Ciudad de la Habana puede ser debido a que las áreas de alimentación están reducidas al máximo por la urbanización. Las especies más representadas entre las recobradas son el Guanabá de la Florida (Nycticorax nycticorax) y el Coco Prieto (Plegadis

falcinellus). El caso del Coco Prieto es llamativo dado los cambios poblacionales marcados que ha experimentado la especie en las últimas décadas a nivel regional, y en especial, en las zonas arroceras de Cuba donde sus poblaciones se incrementaron de forma muy marcada desde la década del 80, al

0

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40

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1910-20 1921-30 1931-40 1941-50 1951-60 1961-70 1971-80 1981-90 1991-00

Década

No

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up

era

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Fig. 1. Número de individuos de Ciconiiformes, anillados en Norteamérica y recuperados en Cuba por década durante el período de 1913 a 1998.

Especie Ha CH M VC H PR Ca Ci SS IJ CA LT Gr SC Gu Total

N. nycticorax B. ibis A. herodias A. alba E. tricolor E. thula E. caerulea E. albus P. falcinellus

15 3 7 6 3 2 4 6 1

0 0 1 0 1 0 0 0 0

8 1 0 4 0 2 0 4 6

3 6 2 2 2 2 1 2 3

6 3 2 7 2 2 2 7 1

9 1 6 6 1 0 4 6 4

8 0 1 2 0 0 0 2 5

3 1 1 1 1 0 0 1 4

11 0 1 2 3 8 0 2 11

2 0 0 0 1 0 0 0 0

1 0 2 1 0 0 1 1 1

1 1 3 3 1 0 0 3 0

2 1 1 1 1 0 0 1 2

4 3 1 0 1 1 0 0 0

3 0 0 1 0 4 1 1 0

76 20 28 36 17 21 13 36 38

Tabla 2. Número de individuos de cada especie analizada del orden Ciconiiformes que han sido recuperados por provincias de Cuba, en el período de 1913 a 1998. Ha = Habana; CH = Ciudad de Habana; M = Matanzas; VC = Villa Clara; H = Holguín; PR = Pinar del Río; Ca = Camaguey; Ci = Cienfuegos; SS = Sancti Spiritus; IJ = Isla de la Juventud; CA = Ciego de Ávila; LT = Las Tunas; Gr = Granma; SC = Santiago de Cuba; Gu = Guantánamo.



punto en que se llegaron a detectar en algunos con-teos poblacionales las mayores cifras de todo el continente (Acosta 1998). En Cuba la dinámica estacional de capturas durante el período estudiado (por meses), muestra que el mayor número de recuperaciones de aves se produjo durante las épocas residencia invernal (171 individuos) comprendidas entre los meses de octu-bre hasta febrero (Fig. 2). Los meses con el valor máximo de recaptura fueron enero y febrero (40 y 41 individuos respectivas), lo que refleja la existen-cia en estos meses de una mayor concentración de individuos del orden en Cuba. Los meses de mayor cantidad de recuperaciones correspondieron a los meses migratorios, aunque la presencia de recupera-ciones en meses intermedios demuestra la mezcla que se produce entre las poblaciones por el hecho de que existan individuos que permanezcan luego de migrar (poblaciones bimodales). Usualmente estas aves que permanecen en las áreas de invernada son ejemplares jóvenes que no están listas para la repro-ducción, la edad promedio de los individuos recap-turados en los meses de junio a agosto fue de 21.8 ± 5.42 meses (n = 22) y para los individuos recaptura-dos en etapa migratoria fue de 28.9 ± 2.93 meses (n = 217; prueba de Mann-Whitney, U = 1851,5, P = 0,08). Estos resultados coinciden completamente con lo descrito por Blanco y Sánchez (2005) para los anátidos. La mayor cantidad de las garzas y cocos recobra-dos en Cuba se realizó entre los 4 y los 10 meses después de haberse anillados (46 %). Se recaptura-ron 39 individuos, equivalentes al 14 % de los reco-brados, que estuvieron anillados entre 10 meses y dos años y 13 (5 %) que se recuperaron más de 10

años después de haber sido anillados: tres Garcilotes (Ardea herodias), tres Garzones (A. alba), una Gar-za Ganadera (Bubulcus ibis), dos Garzas de Rizos (Egretta thula), y cuatro Guanabaes de la Florida. Todas estas especies pueden sobrevivir en vida libre entre 13 y 23 años, según datos de anillados (Clapp et al. 1982). Esta distribución de frecuencias en el tiempo de anilladas puede deberse a que estas aves son capturadas y marcadas en el momento de la reproducción (formación de colonias) y recaptura-das en la migración siguiente, sin haber transcurrido un año. El individuo con mayor tiempo entre anilla-do y recobrado fue un Garcilote (22 años y 9 me-ses). El conjunto de datos de recobrados, tanto de gar-zas como de cocos, en Cuba, sugiere que las migra-ciones tienen un mayor número de individuos pro-venientes de New Jersey, Virginia, Michigan, South Carolina, Mississippi y Ohio y en menor número, de Indiana, Wisconsin, South Dakota, Québec, Kansas, Rhode Island, Pennsylvania, North Dakota, Minne-sota, Maine, Illinois, Georgia, Delaware y Alberta (Tabla 3), aunque esto depende del esfuerzo de ani-llamiento anual en cada estado. Para las aves de los Estados con mayor número de recapturados en Cu-ba, Dusi (1967) sugiere que estas poblaciones mi-gran al sur y hacia el este a través de la Florida hacia Cuba o a lo largo de las Bahamas hacia Puerto Rico. Coffey (1943, 1948) sugirió que las colonias del Mississippi se movían hacia el sur durante la migración, siguiendo rutas de tierra desde el sur-oeste del Valle del Mississippi a través de Louisia-na, Texas y México y pasando a Cuba por la penín-sula de Yucatán. Los individuos de Ohio y Michi-gan, aparentemente, siguen la ruta del sur hasta el

0

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Ene Feb Mar Abr May Jun Jul Ago Sep Oct Noc Dic

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ob

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os

Fig. 2. Dinámica anual de la recuperación de individuos de garzas y cocos anillados en Norteamérica y recuperados en Cuba en el período comprendido entre los años 1913 y el 1998.



golfo y costa del Atlántico para invernar en áreas de Cuba, Jamaica, República Dominicana y probable-mente en otras islas de las Antillas Mayores y Menores (Byrd 1978). La Garza Ganadera (Bubulcus ibis) tiene altas tendencias dispersivas que hacen difícil la separa-ción entre dispersión y migración. Los juveniles después de la cría se dispersan rápidamente cubriendo distancias de 1 900 a 5 000 km. Al pare-cer su tendencia a volar en los grupos mixtos con garzas azules y de rizos, hace que explote los tres corredores principales del grupo: la vía oriental des-de Nova Scotia por la costa atlántica hasta el Mis-sissippi, el corredor central (del este de Kansas has-ta Panamá) y la ruta de la costa pacífica de Alaska hasta México (Byrd 1978). Frederick et al. (1996) analizan la información de

18 713 cocos blancos anillados en EUA entre 1926 y 1985 y sus recuperaciones y también describen la importancia de los humedales de Cuba en la migra-ción invernal de esta especie (17 recuperaciones). Su quinta recomendación de manejo fue, precisa-mente, la necesidad de coordinar esfuerzos con científicos y conservacionistas cubanos. Las investigaciones que involucran anillamientos y recapturas son sólo posibles gracias a la labor cooperativa integrada de muchas personas en un amplio rango geográfico y de tiempo. Si se recono-ce el hecho de que en Norteamérica y el Caribe, cerca del 20 % de las poblaciones de aves acuáticas está declinando (Wetlands International 2003) los estudios de este tipo, capaces de detectar y monito-rear cambios a gran escala son imprescindibles. Esto es un llamado a la aplicación de un enfoque a escala continental de las investigaciones y de la conservación de las aves acuáticas, independiente de barreras políticas y culturales.

AGRADECIMIENTOS Al Dr. Pedro Blanco que puso a nuestra disposi-ción la base de datos de recuperaciones en Cuba. Al LCAM por su autorización para realizar los anilla-mientos y por los anillos, y al Dr. J. A. Kushlan, que donó las pinzas de anillamiento. Al Wayne Arendt, Leopoldo Miranda y Oliver Komar por revisar el manuscrito. Se agradece el apoyo de la Sociedad de Ornitología del Caribe e Ideawild. Debe reconocer-se el esforzado trabajo de los estudiantes de la Uni-versidad de La Habana que, voluntariamente, traba-jaron en la campaña de anillamiento de flamencos y de garzas: Ronar López, Yadiley Estévez, José L. Ponce de León y Gisela M. López.

LITERATURA CITADA ACOSTA, M. 1998. Segregación del nicho en la co-

munidad de aves acuáticas del agroecosistema arrocero en Cuba. Tesis en opción al grado de Dr. en Ciencias Biológicas. Universidad de La Haba-na, Cuba. 110 pp.

BAILLIE, S. R. 1995. Uses of ringing data for the conservation and management of bird popula-tions: a ringing squeme perspective. Journal of Applied Statistics 22:967-987

BLANCO P. R., Y B. O. SÁNCHEZ. 2005. Recupera-ción de aves migratorias neárticas del orden An-seriformes en Cuba. Journal of Caribbean Ornit-hology 18:1-6.

BLANCO, P., B. SÁNCHEZ, P. DEL POZO, Y J. MORA-

LES. 2002. Recapturas del Flamenco Rosado (Phoenicopterus ruber) en Cuba durante el

Estado No. de Individuos

New Jersey Virginia Carolina Sur Michigan Mississippi Ohio Florida Maryland Alabama Ontario Massachussets Carolina Norte Illinois Quebec Georgia Wisconsin Delaware Rhode Island Pennsylvania Maine Minnesota Dakota Norte Kansas Alberta Indiana Dakota Sur

53 30 30 30 24 18 17 16 14 13 10 10 6 4 3 3 3 3 3 3 2 1 1 1 1 1

Tabla 3. Estados o provincias norteamericanas don-de fueron anillados los individuos anillados del orden Ciconiiformes capturados y recuperados en Cuba en el período de 1913 y 1998.



período de 1966 al 2000. Pitirre 15:31-33. BYRD, M. A. 1978. Dispersal and movement of six

North American ciconiiforms. Pp. 161-185 en Wading birds (A. Sprunt IV, J. Ogden, y S. Winckler, eds). National Audubon Society Res. earch Reports no. 7.

BROWDER, J. A. 1973. Long-distance movements of Cattle Egret. Bird-Banding 44:158-170.

CLAPP, R. B., M. K. KLIMKIEWICZ, Y J. H. KENNARD. 1982. Longevity records of North American birds: Gaviidae through Alcidae. Jour-nal of Field Ornithology 53: 81-208.

COFFEY, B. B., JR. 1943. Post-juvenal migration of herons. Bird-Banding 14:34-39.

COFFEY, B. B., JR. 1948. Post-juvenal migration of herons. Bird-Banding 49:1-5.

DENIS, D., M. ACOSTA, A. JIMÉNEZ, O. TORRES, Y A. RODRÍGUEZ. 2003. Las zancudas. Pp. 112-127 en Aves de Cuba (H. González, ed.). UPC Print, Vaasa, Finland.

DENNIS, J. V. 1986. European encounters of birds ringed in North America. Dutch Birding 8:41-44.

DUSI, L. J. 1967. Migration in the Little Blue Heron. Wilson Bulletin 79:223-235.

FREDERICK, P. C., K. L. BILDSTEIN, B. FLEURY, Y J. OGDENS. 1996. Conservation of large, nomadic populations of White Ibises (Eudocimus albus) in the United States. Conservation Biology 10:203-216.

GONZÁLEZ, H. 1996. Composición y abundancia de las comunidades de aves residentes y migratorias

en Cuba occidental y central durante el periodo migratorio. Tesis de Doctorado, Universidad de La Habana, Cuba. 93 pp.

GONZÁLEZ, H., J. SIROIS, M. K. MCNICHOLLS, P. B. HAMEL, E. GODÍNEZ, R. D. MCRAE, M. ACOSTA, D. RODRÍGUEZ, C. MARCOS, Y J. HERNÁNDEZ. 1990. Resultados preliminares de un proyecto cooperativo de anillamiento de aves en la Ciénaga de Zapata, Cuba, enero de 1988. Progress Notes, Canadian Wildlife Service no. 197.

MYKUSKA, T., J. A. KUSHLAN, Y S. HARTLEY. 1998. Key areas for wintering North American herons. Colonial Waterbirds 12:125-134

RODRÍGUEZ, A. 2004. Análisis de los patrones de migración de varias especies de anátidos en el neotrópico durante el periodo 1910-2004. Tesis en opción al grado de Master en Ciencias, Uni-versidad de La Habana, Cuba. 78 pp.

RYDER, R. A. 1978. Breeding distribution, move-ments, and mortality of Snowy Egrets in North America. Pp. 197–205 en Wading birds (A. Sprunt, IV, J. Ogden y S. Winckler, eds.). Na-tional Audubon Society Research Reports no. 7.

TOWNSEND, C. W. 1931. The post-Breeding north-ern migration of North American Herons. Pro-ceedings of the International Ornithological Con-gress 7:366-369.

WETLANDS INTERNATIONAL. 2002. Waterbird popu-lation estimates. 3rd ed. Global Series no. 12. Wageningen, the Netherlands.


SECOND AND THIRD RECORDS OF WESTERN MARSH-HARRIER (CIRCUS

AERUGINOSUS) FOR THE WESTERN HEMISPHERE IN PUERTO RICO

CHRISTOPHER L. MERKORD¹, RAFY RODRÍGUEZ², AND JOHN FAABORG³

¹105 Tucker Hall, University of Missouri, Columbia, Missouri 65211, email: [email protected]; ²Calle del Río

# 21 Norte, Mayagüez, Puerto Rico 00680, email: [email protected]; ³110 Tucker Hall, University of Missouri,

Columbia, Missouri 65211, email: [email protected] Abstract: The Western Marsh-Harrier (Circus aeruginosus) is an Eurasian species rarely recorded in the Western Hemisphere. We document a female at the Laguna Cartagena National Wildlife Refuge in Puerto Rico from 14 Janu-ary to 30 March 2004 and an immature at the same locality from 11 January to 11 February 2006. These records represent the second and third for the Western Hemisphere and the first for Puerto Rico. Key words: Circus aeruginosus, distributional records, Puerto Rico, Western Marsh-Harrier Resumen: SEGUNDO Y TERCER REGISTRO DE AGUILUCHO LAGUNERO OCCIDENTAL (CIRCUS AERUGINOSUS) PARA EL HEMISFERIO OCCIDENTAL EN PUERTO RICO. El Aguilucho Lagunero Occidental (Circus aeruginosus) es una especie euroasiática raramente registrada en el hemisferio occidental. En este trabajo se documenta una hembra en el Refugio Nacional de Vida Silvestre Laguna Cartagena en Puerto Rico entre el 14 de junio al 30 de marzo del 2004, y un inmaduro en esa misma localidad entre el 11 de enero y el 11 de febrero de 2006. Estos registros representan el segundo y tercero para el hemisferio occidental y el primero para Puerto Rico. Palabras clave: Aguilucho Lagunero Occidental, Circus aeroginosus, Puerto Rico, registros de distribución Résumé : DEUXIEME ET TROISIEME OBSERVATIONS DE BUSARD DES ROSEAUX (CIRCUS AERUGINOSUS) POUR L’ HEMISPHERE OCCIDENTAL A PORTO RICO. Le Busard des roseaux (Circus aeruginosus) est une espèce européenne rarement observée dans l’hémisphère occidental. Nous fournissons des informations sur l’observation d’une femelle à Laguna Cartagena National Wildlife Refuge à Porto Rico du14 janvier au 30 mars 2004 et d’un immature au même endroit du 11 janvier au 11 février 2006. Il s’agit des deuxième et troisième observations pour l’hémisphère occiden-tal et les premières pour Porto Rico. Mots-clés : Busard des roseaux, Circus aeruginosus, distribution, Porto Rico

THE WESTERN MARSH-HARRIER (Circus aerugi-

nosus) is an Eurasian species rarely recorded in the Western Hemisphere. On 4 December 1994, a fe-male Western Marsh-Harrier was reported from Chincoteague National Wildlife Refuge, Virginia, USA (Shedd et al. 1998), but lack of photographic documentation led the American Ornithologists’ Union to relegate C. aeruginosus to the Appendix of the Check-list of North American Birds (AOU 2000). On 11 November 2002, another female Western Marsh-Harrier was found and photo-graphed at Grand Cul-de-Sac Marin on the island of Guadeloupe (Levesque and Malglaive 2004), pro-viding the first fully documented record. The spe-cies has shown some propensity to stray, with re-cords from several islands in the eastern Atlantic and the Seychelles in the Indian Ocean (Ferguson-Lees and Christie 2001). In this note we report the second and third records for the Western Hemi-sphere, both from Puerto Rico.

OBSERVATIONS On 14 January 2004, Chris Merkord, John

Faaborg, Wes Bailey, Courtney Kerns, and Kelly Gamble saw a female Western Marsh-Harrier (Circus aeruginosus) at the Laguna Cartagena Na-tional Wildlife Refuge in Puerto Rico. We observed the bird flying over the open water and surrounding marsh. Although it kept the numerous ducks in con-stant flight it never gave chase. Twice the bird landed in woody vegetation on the edge of the lake, perching just above the ground. We observed the bird at midday for approximately 15 minutes using Swarovski EL 8.5×42 binoculars, Leica binoculars, and a Bushnell Spacemaster 60mm spotting scope with a 22× wide angle lens. In flight the Western Marsh-Harrier gave the im-pression of a relatively long-winged, long-tailed raptor of uniform dark brown coloration. The bird’s flight was buoyant as it glided, swooped, and hov-ered with legs extended below. The rump was a lighter shade of brown, contrasting slightly with the darker back and tail. Although we could not see any barring on either side of the squared, apparently uniformly brown tail, the photos do show 4 to 5 dark bars on the underside of the tail (Fig. 1). One



observer remarked on a pale area at the base of the primaries on the underside of the wing. Whitish spots were evident at the proximal leading edge of the wing when viewed head-on, although we did not note the entire leading edge of the wings to be pale, as characteristic of females of this species. Most striking was the cream-colored crown extending from the bill to the nape, passing just above the eyes. A slightly less striking but still noticeable cream-colored throat contrasted with the dark mask through the eyes. Local birders reported a dark-rumped harrier in the area as early as 27 December 2003 (S. Colón pers. comm.). On 25 January 2004, Rafy Rodríguez observed a harrier matching our description at La-guna Cartagena and obtained video footage of the bird with a handheld digital video camera. Stills of that video are presented here (Fig. 1). Reports of a Western Marsh-Harrier at Laguna Cartagena conti-

Fig. 1. Female Western Marsh-Harrier (Circus aeruginosus) at Laguna Cartagena, Puerto Rico, 25 January 2004. Video stills by R. Rodríguez.

nued to 30 March 2004 (S. Colón pers. comm.). On 11 January 2006, John Faaborg and others saw a similarly-plumaged bird, again at Laguna Cartagena. Written descriptions and photographs by Rafy Rodríguez (Fig. 2), taken on 11 February 2006, show a darker overall coloration and lack of white on the leading edge of the wings, consistent with a juvenile Western Marsh-Harrier (Beaman and Madge 1998) and noticeably different than the adult female from the 2004 sightings. The 2006 sightings would thus appear to represent a separate individual from the 2004 sightings.

DISCUSSION The 2004 and 2006 sightings represent the second and third documented records, respectively, of C.

aeruginosus for the New World. Only two other species of Eurasian raptors have been reported from the Caribbean region. A specimen of a Eurasian

MERKORD ET AL. — CIRCUS AERUGINOSUS IN PUERTO RICO


MERKORD ET AL. — CIRCUS AERUGINOSUS IN PUERTO RICO

Fig. 2. Juvenile Western Marsh-Harrier (Circus aeruginosus) at Laguna Cartagena, Puerto Rico, 11 February 2006. Photos by R. Rodríguez.

Kestrel (Falco tinnunculus) was taken in Martinique on 9 December 1949 (Pinchon and Vaurie 1961), and one was photographed in Trinidad during 17 December 2003 to 1 January 2004 (Kenefick and Hayes 2006). A Black Kite (Milvus migrans) was found in Dominica on 19 April 1999 (Norton et al. 2003), and a second was found in the British Virgin Islands in mid-October 1999 (Mazar Barnett and Kirwan 2002). See Ebels (2002) for a summary of sightings of 42 other Palearctic species in the Carib-bean region.

ACKNOWLEDGMENTS We thank Javier Mercado and Matthew Anderson for help with identification and Wayne Arendt, Christopher Conner, Stacy Small, Jennifer White, and an anonymous reviewer for reviewing this manuscript.

LITERATURE CITED AMERICAN ORNITHOLOGISTS’ UNION. 2000. Forty-

second supplement to the American Ornitholo-gists’ Union Check-list of North American birds. Auk 117:847-858.

BEAMAN, M., AND S. MADGE. 1998. The handbook of bird identification: for Europe and the western Palearctic. Princeton University Press, Princeton, NJ.

EBELS, E. B. 2002. Transatlantic vagrancy of Palearctic species to the Caribbean region. Dutch Birding 24:202-209.

FERGUSON-LEES, J., AND D. A. CHRISTIE. 2001. Raptors of the World. Houghton Mifflin Com-pany, New York, NY.

KENEFICK, M., AND F. E. HAYES. 2006. Trans-Atlantic vagrancy of Palearctic birds in Trinidad and Tobago. Journal of Caribbean Ornithology 19:in press.

LEVESQUE, A., AND L. MALGLAIVE. 2004. First documented record of Marsh Harrier for the West Indies and the New World. North American Birds 57:564-565.

MAZAR BARNETT, J., AND G. M. KIRWAN. 2002. Published records from the literature: Caribbean. Cotinga 17:82-83.

NORTON, R. L., A. WHITE, AND A. DOBSON. 2003. West Indies & Bermuda. North American Birds 57:131-133.

PINCHON, P. R., AND C. VAURIE. 1961. The Kestrel (Falco tinnunculus) in the New World. Auk 78:92-93.

SHEDD, D. H., R. D. GETTINGER, B. L. SHEDD, AND F. R. SCOTT. 1998. First record of a Western Marsh Harrier (Circus aeruginosis) [sic] in Vir-ginia. Raven 69:56.



FIRST RECORD OF THE WESTERN REEF-HERON (EGRETTA GULARIS) FOR ST. VINCENT AND THE GRENADINES

MICHAEL R. PAICE

8d, Rochdale Way, Deptford, London, SE8 4LY, England; e-mail: [email protected]

Abstract: An immature dark-morph Western Reef-Heron (Egretta gularis), almost certainly of the nominate race E.

g gularis, was observed and photographed on Mustique Island, St. Vincent and the Grenadines, on 1 February 2004, representing the 15th record of Western Reef-Heron for the Western Hemisphere and the first for St. Vincent and the Grenadines. Key words: Ardeidae, distributional record, Egretta gularis, St. Vincent and the Grenadines, Western Reef-Heron Resumen: PRIMER REGISTRO DE LA GARCETA DIMORFA (EGRETTA GULARIS) PARA SAN VICENTE Y LAS GRANADI-

NAS. Un individuo inmaduro del morfo oscuro de Egretta gularis, casi seguramente de la raza nominal E. g. gularis, fue observada y fotografiada en Isla Mustique, San Vicente y las Granadinas el 1ero de febrero de 2004. Este repre-senta el registro número 15 de la especie para el hemisferio occidental y el primero para estas islas. Palabras clave: Ardeidae, Egretta gularis, Garceta Dimorfa, registro de distribución, San Vicente y las Granadinas Résumé : PREMIERE OBSERVATION DE L’AIGRETTE DES RECIFS (EGRETTA GULARIS) POUR ST. VINCENT ET LES GRENADINES. Une Aigrette des récifs immature de forme sombre (Egretta gularis), très certainement de la race no-minale E. g. gularis, a été observée et photographiée sur l’Ile Moustique, St. Vincent et les Grenadines, le 1er février 2004. Il s’agit de la 15ème observation pour l’hémisphère occidental et la première pour Saint Vincent et les Grena-dines. Mots-clés : Aigrette des récifs, Ardeidae, distribution, Egretta gularis, St. Vincent et les Grenadines

THE WESTERN REEF-HERON (Egretta g. gularis) occurs from the Red Sea to south-east India and in West Africa north to western Europe (Snow and Perrins 1998). The nominate race, E. g. gularis, breeds in West Africa, and E. g. schistacea breeds in East Africa eastward to India. Although both races regularly occur north to southern Europe (Dubois and Yésou 1995), the nominate race is con-sidered a very rare but increasing vagrant to the West Indies region, where it has been reported from St. Lucia (four records, one of two birds; Keith 1997), Barbados (seven records; Mlodinow et al. 2004), Trinidad (one in 1986, the first confirmed record for South America; Murphy and Nanan 1987), and Tobago (one in 2000-2002; Kenefick and Hayes 2006). A summary of Western Reef-Heron records in the Western Hemisphere through 2004 is presented by Mlodinow et al. (2004). In this note I document the first record of a Western Reef-Heron for St. Vincent and the Grenadines.

OBSERVATIONS

On 1 February 2004 I observed and photographed (Fig. 1) a dark heron on Mustique Island in the Grenadines from 14:25-14:55 hr and later, while accompanied by R. Touche and O. Touche, from 15:45-16:15 hr. The bird was observed on a rocky

reef off the sandy beach at Lagoon Bay West, mid-way down the west coast of Mustique Island, at its westernmost point. The bird was feeding using sev-eral techniques including the spectacular ‘umbrella’ wing shading action. The weather was warm with bright sunshine and a light breeze. The bird was observed in good light from about as close as 10 m through 8×40 binoculars and through a tripod-mounted 30× telescope.

The bird was approximately the same size as a Little Blue Heron (E. caerulea) that chased it during our observations. However, the bill appeared longer, straighter, and proportionately thinner, the head appeared smaller, and the neck appeared longer and thinner. The plumage was generally dark grey with a brownish tint on the back and downy white (or very pale grey) around the vent from behind the legs to the tail. The chin and throat were white, with the white extending from the base of the lower mandi-ble to beyond the eyes and for about the same dis-tance downward on the throat. The bill was greyish, not black, and lacked a dark tip as in E. caerulea. The grey lores blended without contrast with the grey upper head colour. The legs were black with bright lime-green feet, the lime-green colour ex-tending about 2.5 cm up the tarsi. The irides were white.


Fig. 1. Immature dark-morph Western Reef-Heron (Egretta gularis) at Mustique Island, St. Vincent and the Grenadines, 1 February 2004. Photos by M. R. Paice.

sphere, on Barbados, where a breeding colony be-came established with as many as 20 breeding pairs and a total population of about 80 individuals (Massiah 1996). Little Egrets also occur regularly on Trinidad and Tobago, with more than 50 records to date (Hayes and White 2001). They have also been found on St Lucia, Puerto Rico, Guadeloupe, Martinique, and Aruba (Mlodinow 2004, Mlodinow et al. 2004).

The Little Egret is white and is thus unlikely to be confused with a dark morph Western Reef-Heron, yet the existence of dark-morph Little Egrets has often been claimed (e.g., Brown et al. 1982, Dubois and Yésou 1995, Snow and Perrins 1998, van den Berg 1999, Borrow and Demey 2001). However, the genetic origin of the dark plumage in such birds is usually unknown and they are very rare (Kushlan and Hancock 2005). Furthermore, interbreeding between Little Egret and E .g. schistacea popula-tions has been reported in western India (Parasharya and Naik 1984) and interbreeding between Little Egret and E. g. gularis has been observed in eastern Spain (Dies et al. 2001). Suspected E. g. gularis × E. garzetta hybrids in eastern Spain were pale grey with variable amounts of white on the head, wings, and underparts, even in adults (Dies et al. 2001). Photographs of birds accepted as hybrids show this plumage range and a bill that is blacker and often thinner than that of E. g. gularis (de Juana 2002; see also the websites of the Dies brothers and Ricard Gutiérrez at www.rarebirdspain.net). Parasharya and Naik (1987) considered blue/grey lores and a black bill as evidence of Little Egret gene flow into the schistacea population.

Of the two races of E. gularis, schistacea exhibits more obvious and consistent structural differences from the Little Egret (Dubois and Yésou 1995). In the more westerly populations of schistacea (e.g., those in the Sinai and Israel), the white morph pre-dominates, comprising 80% or more of the popula-tion (Shirihai 1996, van den Berg 1999), whereas in gularis populations in Senegal, the Gambia, and Mauritania, less than 1% are white (Dubois and Yésou 1995). In comparison with Little Egret, Western Reef-Heron has a shorter tarsus in relation to its bill length, the bill is usually thicker, paler and slightly downcurved, and the legs are often paler. Although the bill of the heron at Mustique Island appeared rather slender and pointed and its legs appeared rather black as in a Little Egret or Little Egret × Western Reef-Heron, the lack of black bill colouration combined with the well defined white throat patch and lack of white plumage elsewhere

DISCUSSION The combination of a white throat and yellowish

green feet eliminate the similarly sized and similarly dark Little Blue Heron and Tricolored Heron (E.

tricolor) of the New World. The Little Egret occurs in Asia, Africa, and south-

ern Europe, and has been spreading north-west in Europe since ca. 1960 (Mlodinow et al. 2004). It was first recorded in the West Indies in 1954 (Bond 1966). An increase in sightings in the 1980s culmi-nated in the discovery by Martin Frost in December 1994 of the first breeding pair in the Western Hemi-

PAICE — EGRETTA GULARIS IN ST. VINCENT AND THE GRENADINES


PAICE — EGRETTA GULARIS IN ST. VINCENT AND THE GRENADINES

are more consistent with a dark-morph nominate Western Reef-Heron. The brownish tint on the back and pale belly indicate it was a juvenile.

This sighting provides the 15th record of Western Reef-Heron for the Western Hemisphere and the first for St. Vincent and the Grenadines. The in-creasing number of sightings of Western Reef-Heron in the Caribbean during the last few decades suggests that this species may well follow the Little Egret in colonising the Caribbean.

ACKNOWLEDGEMENTS I thank Rodney and Ouda Touche for accompany-

ing me to see this bird and for sharing my interest in the birds of the island. I also thank Geoff Hilton and colleagues at the RSPB, and John Archer for com-menting on the photographs, and Nick Bertrand, Steven Mlodinow, William Murphy, and my father, E. S. Paice, for commenting on the text. I thank the staff at the British Library in London and at the London Natural History Museum Library, Tring, for being so helpful. I especially thank Basil Charles and Dana Gillespie and their charity, the Mustique Blues Festival, for making my visits to Mustique possible. The Mustique Blues Festival promotes the education of disadvantaged St. Vincent children through the Basil Charles Foundation.

LITERATURE CITED BOND. J. 1966. Eleventh supplement to the Check-

list of the birds of the West Indies. Academy of Natural Sciences, Philadelphia, PA.

BORROW, N., AND R. DEMEY. 2001. Birds of West-ern Africa. Christopher Helm, London.

BROWN, L. H., E. K. URBAN, AND K. NEWMAN. 1982. The birds of Africa. Vol. 1. Academic Press, London.

DE JUANA, E. 2002. Observaciones de aves raras en España. Ardeola 49:141-171.

DIES, J. I., J. PROSPER, AND B. DIES. 2001. Occa-

sional breeding by Western Reef Egret in eastern Spain. British Birds 94:382-386.

DUBOIS, P. J., AND P. YÉSOU. 1995. Identification of Western Reef Egrets and dark Little Egrets. British Birds 88:307-319.

KEITH, A. R. 1997. The birds of St Lucia West In-dies. British Ornithologists’ Union Checklist no. 15. London.

KENEFICK, M., AND F. E. HAYES. 2006. Trans-Atlantic vagrancy of Palearctic birds in Trinidad and Tobago. Journal of Caribbean Ornithology 19:in press.

KUSHLAN, J. A., AND J. A. HANCOCK. 2005. The herons. Oxford University Press, Oxford.

MASSIAH, E. 1996. Identification of Snowy Egret and Little Egret. Birding World 9:434-444.

MLODINOW, S. G. 2004. First records of Little Egret, Green-winged Teal, Swallow-tailed Kite, Tennessee Warbler, and Red-breasted Blackbird from Aruba. North American Birds 57:559-561.

MLODINOW, S. G., W.E. DAVIS, JR., AND J.I. DIES. 2004. Possible anywhere: Little Egret. Birding 36:52-62.

MURPHY, W. L., AND W. NANAN. 1987. First con-firmed record of Western Reef-Heron (Egretta

gularis) for South America. American Birds 41:16-27.

PARASHARYA, B. M., AND R. M. NAIK. 1987. Changes in the soft part coloration of the Indian Reef Heron, Egretta gularis (Bosc) related to age and breeding status. Journal of the Bombay Natu-ral History Society 84:1-6.

SHIRIHAI, H. 1996. The birds of Israel. Princeton University Press, London.

SNOW, D. W., AND C. M. PERRINS. 1998. The birds of the Western Palearctic. Concise ed. Vol. 1. Oxford University Press, Oxford.

VAN DEN BERG, A. B. 1999. Dark-morph egret in Morocco in April 1997. Dutch Birding 21:8-15.


STATUS OF THE AMERICAN OYSTERCATCHER (HAEMATOPUS

PALLIATUS) IN ST. VINCENT AND THE GRENADINES

FLOYD E. HAYES1, MICHAEL R. PAICE2, TONY BLUNDEN3, P. WILLIAM SMITH4, SUSAN A. SMITH4, GRAHAM WHITE5, AND MARTIN D. FROST6

1Department of Life Sciences, University of the West Indies, St. Augustine, Trinidad and Tobago; e-mail:

[email protected]; current address: Department of Biology, Pacific Union College, 1 Angwin Ave., Angwin,

CA 94508, USA; 28d, Rochdale Way, Deptford, London, SE8 4LY, England; e-mail: [email protected]; 314 White Hill Ecchinswell, Nr Newbury, Berkshire, RG20 4UF, UK; e-mail: [email protected]; 415917 NE Union Rd.

#69, Ridgefield, WA 98642,USA; e-mail: [email protected]; 5Waterloo Estate, Carapichaima, Trinidad and

Tobago; e-mail: [email protected]; 6Featherbed Lane, St. John, Barbados; e-mail: [email protected] Abstract: The American Oystercatcher (Haematopus palliatus) was first reported from the Grenadine islands of St. Vincent and the Grenadines in 1950 by James Bond, who merely stated that it “evidently breeds in the Grenadines (Tobago Cays)” but provided no further information. We report recent sightings of: up to five oystercatchers at Be-quia during 13-22 March 1993, one on 5 August 1999, and one on 25-27 June 2004; up to five at Mustique during January-February 1997, 1998, and 2001-2006; two at Petit Nevis on 5 August 1999; up to two at Mayreau on 25 May 1998, 27 December 2001, and August 2002; and three at Battowia on 26 June 2004. These observations provide evidence that either small numbers of non-breeding birds regularly visit the Grenadines or a small population may breed in the Grenadines. Key words: American Oystercatcher, Battowia, Bequia, Haematopus palliatus, Mayreau, Mustique, Petit Nevis, status, St. Vincent and the Grenadines Resumen: ESTATUS DEL OSTRERO (HAEMATOPUS PALLIATUS) EN SAN VICENTE Y LAS GRANADINAS. El Ostrero (Haematopus palliatus) fue registrado por primera vez para las islas Granadinas de San Vicente y las Granadinas en 1950 por James Bond, quien solamente señaló que “evidentemente cría en las Granadinas (Islas Tobago)” sin proveer más información. En este trabajo se registran recientes avistamientos de hasta cinco ostreros en Bequia du-rante el 13 – 22 de marzo de 1993, uno el 5 de agosto de 1999, otro entre el 25-27 de junio del 2004, hasta cinco en Mustique durante enero y febrero de 1997, 1998 y entre 2001-2006; dos más en Petit Nevis el 5 de agosto de 1999, hasta dos en Mayreau el 25 de mayo de 1998, el 27 de diciembre del 2001, y agosto del 2002, y tres en Battowia el 26 de junio de 2004. Estas observaciones proveen evidencias de que un pequeño número de aves visitan regular-mente las Granadinas o de que una pequeña población puede estar criando en ella. Palabras clave: Battowia, Bequia, estado, Haematopus palliatus, Mayreau, Mustique, Ostrero, Petit Nevis, San Vicente y las Granadinas Résumé : STATUT DE L’HUITRIER D’AMERIQUE (HAEMATOPUS PALLIATUS) DANS ST. VINCENT ET LES GRENADINES. L’Huitrier d’Amérique (Haematopus palliatus) a été observé pour la première fois dans les iles Grenadines de St. Vincent et les Grenadines par James Bond en 1950. Celui-ci mentionnait juste que « il niche manifestement dans les Grenadines (Tobago Cays) » sans fournir plus d’information. Nous rapportons ici des observations récentes de, jus-qu’à 5 huitriers à Bequia du 13 au 22 mars 1993, une le 5 août 1999 et une autre du 25 au 27 juin 2004 ; jusqu’à cinq à Moustique en janvier et février 1997, 1998 et de 2001 à 2006 ; deux à Petit Nevis le 5 août 1999 ; jusqu’à deux à Mayreau les 25 mai 1998, 27 décembre 2001 et août 2002 ; et trois à Battowia le 26 juin 2004. Ces observations révèlent que, soit un petit nombre d’oiseaux non nicheurs visite régulièrement les Grenadines ou alors qu’une petite population pourrait y nicher. Mots-clés : Battowia, Bequia, Haematopus palliatus, Huitrier d’Amérique, Mayreau, Mustique, Petit Nevis, statut, St. Vincent et les Grenadines

IN THE CARIBBEAN REGION, the American Oystercatcher (Haematopus palliatus) breeds lo-cally along the Atlantic coast of North America from Florida to the Yucatan Peninsula, the Baha-mas, Greater Antilles, northern Lesser Antilles, and along the north coast of South America (Nol and

Humphrey 1994, American Ornithologists’ Union 1998, Raffaele et al. 1998). In the Grenadine islands of St. Vincent and the Grenadines, which are sel-dom visited by birders or ornithologists, the status of the American Oystercatcher remains poorly known and is the subject of this note.



RECENT OBSERVATIONS In March 1993, Blunden visited Bequia for 12 days and briefly visited Mustique twice. In the eve-ning of 13 March, five birds were noted in Spring Bay, Bequia, where they appeared to be roosting on exposed rocks. Presumably the same group of birds was heard after dark at the same locality on 22 March. At L’Anse Chemin, west of Bequia Head, Bequia, one was heard calling and another seen eating a shellfish on 16 March; presumably these individuals were different than the ones at Spring Bay. In January and February 1997, Paice spent 19 days in Mustique and observed two at North Point on 4 February 1997. Paice returned to Mustique for 17 days in January and February 1998, and ob-served two fly past Pasture Bay on the east coast on 27 January, three at North Point on 1 February, three at South Point on 4 February, and two at La-goon Bay West on the west coast on 6 February. On 25 May 1998, while traveling past the north-western tip of Mayreau aboard the St. Vincent mail-boat, the Smiths observed a pair along the shoreline. These were the only birds seen by them during 4 days on Bequia, 2 days on Union Island, and their passage of several islands in the Grenadines, includ-ing Canouan. During a 6 day visit to Bequia in August 1999, White found a single bird along the rocky coast between Friendship Bay and the Fishing Depot op-posite Petit Nevis on 5 August 1999. About 2 hr later, two were seen foraging on a rocky shelf on the northeast side of Petit Nevis; one of the two may have been seen earlier on Bequia. During a 15 day visit to Mustique in January and February 2001, Paice observed one on the west side of Cape Lookout, on the north coast, on 25 January, two at Britannia Bay on the west coast on 28 January, two at North Point on 3 February, and

HISTORIC STATUS The American Oystercatcher was not mentioned in early chronicles of ornithologists visiting St. Vin-cent and the Grenadines (Wells 1902, Clark 1905, Bond 1936, Devas c. 1943), suggesting that it was either absent or overlooked. The first account of its occurrence appears to be that of Bond (1950:38), who briefly stated that it “evidently breeds in the Grenadines (Tobago Cays)” but provided no further details. The presumed breeding of American Oystercatcher in the Grenadines was mentioned repeatedly by the American Ornithologists’ Union (1957, 1983, 1998), but inexplicably the species was not listed by Raffaele et al. (1998) for St. Vin-cent and the Grenadines. None were seen during extensive ornithological field work within the archi-pelago by Joseph Wunderle (pers. comm.) during the mid-to-late 1970s.

Fig. 1. American Oystercatcher (Haematopus pallia-

tus) at Lagoon Bay West, Mustique, 28 January 2003. Photo by M. R. Paice.

Table 1. Monthly summary of the maximum number of American Oystercatchers (Haemaotopus palliatus) observed on each island of the Grenadines.

Island Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Bequia Battowia Mayreau Mustique Petit Nevis

– – – 2 –

– – – 5 –

5 – – – –

– – – – –

– – 2 – –

1 3 – – –

– – – – –

2 – 1 – 2

– – – – –

– – – – –

– – – – –

– – 2 – –

HAYES ET AL. — HAEMATOPUS PALLIATUS IN THE GRENADINES



Fig. 2. Map of the Grenadine islands of St. Vincent and the Grenadines, with arrows indicating localities of recent American Oystercatcher (Haematopus palliatus) sightings.

three at South Point on 6 February. While traveling aboard the yacht Hurricane on 27 December 2001, Hayes observed a pair at Monkey Point, Mayreau, which flew eastward over Saline Bay and then returned to Monkey Point. These were the only birds seen during brief visits by boat to Bequia, Canouan, Mayreau, Tobago Cays, Union Island, and Palm Island on 23, 27, and 28 December 2001. During 2002-2006, Paice returned repeatedly to Mustique during January and February, spending 16 days on each occasion. In 2002, one was seen at Lagoon Bay West on 23 and 27 January, one flying south at Britannia Bay on 29 and 31 January, and two flying south at Britannia Bay on 4 February. In 2003, three were at Lagoon Bay West on 28 January (Fig. 1). In 2004, two were at Lagoon Bay West on

28 January and one on 7 February, and five were at Lovell, at the north end of Britannia Bay, on 8 Feb-ruary. In 2005, one was on a rocky islet off L’Anse-coy Bay, on the north coast. In 2006, two were seen at Lovell/Britannia Bay on 18 and 19 January, and one on 22 January. Two were seen on the rocky islet off L’Ansecoy Bay, on the north coast on 21 Janu-ary and one on 27 January, and two were seen on Wilkes Island (another tiny rocky islet) off the west coast towards the southern end of Mustique on 26 January. In August 2002, Wayne Burke (pers. comm.) saw one at the northern tip of Mayreau. In 2004, Frost and Wayne Burke observed one on St. Elairs, a cay at the mouth of Friendship Bay, Bequia, on 25 June, and one on Semples Cay off Bequia on 27 June. On 26 June, Frost and Burke observed three on the

Bequia

Petit

NevisIsla à

Quatre

Battowia

Baliceaux

Mustique

Petit

Mustique

SavanPetit

Canouan

Canouan

Mayreau

UnionPalm

Petit St.

Vincent

Tobago

Cays



north side of Battowia and one (possibly one of the three) on the south side. A visit by Frost to Tobago Cays and Mayreau on 20 and 21 January 2006 failed to produce any.

DISCUSSION In the northern Lesser Antilles, small oyster-catcher populations apparently breed locally and may be increasing in St. Martin, St. Bartholomew, Guadeloupe, and St. Lucia (Benito-Espinal 1990, Leck and Norton 1991, Keith 1997). Our observa-tions of up to five birds on multiple islands of the Grenadine islands of St. Vincent and the Grenadines (Fig. 2) at various months of the year with no appar-ent seasonal pattern (Table 1), provide evidence that either small numbers of non-breeding birds regu-larly visit the Grenadines from an unknown source population (northern Caribbean or northern South America) or a small population may breed in the Grenadines, potentially comprising the southern-most breeding population in the Lesser Antilles. Given the increasing anthropogenic threats to the marine and littoral ecosystems of the Grenadines (Anonymous 1991), a thorough survey of breeding seabirds and shorebirds in the islands is urgently needed.

ACKNOWLEDGMENTS We thank E. Nol and J. Wunderle for reviewing

an earlier version of the manuscript. F. E. Hayes was funded by a travel grant from the University of the West Indies. M. R. Paice thanks Basil Charles and Dana Gillespie and their charity, the Mustique Blues Festival, which promotes the education of disadvantaged St. Vincent children through the Basil Charles Foundation, for making visits to Mustique possible. We thank W. Burke for provid-ing an unpublished observation, J. C. Eitniear for providing a pertinent reference, and A. Levesque and F. Providence for comments on the status of American Oystercatcher in Guadeloupe and St. Vin-cent, respectively.

LITERATURE CITED AMERICAN ORNITHOLOGISTS’ UNION. 1957. Check-

list of North American birds. Lord Baltimore Press, Baltimore, MD.

AMERICAN ORNITHOLOGISTS’ UNION. 1983. Check-list of North American birds. 6th ed. American Ornithologists’ Union, Washington, DC.

AMERICAN ORNITHOLOGISTS’ UNION. 1998. Check-list of North American birds. 7th ed. American Ornithologists’ Union, Washington, DC.

ANONYMOUS. 1991. St. Vincent and the Grena-dines: environmental profile. Caribbean Conser-vation Association, St. Michael, Barbados.

BENITO-ESPINAL, E. 1990. Oiseaux des Petites An-tilles. Editions du Latanier, St-Barthelemy.

BOND, J. 1936. Birds of the West Indies. Academy of Natural Sciences, Philadelphia.

BOND, J. 1950. Check-list of birds of the West In-dies. Academy of Natural Sciences, Philadelphia.

CLARK, A. H. 1905. Birds of the southern Lesser Antilles. Proceedings of the Boston Society of Natural History 32:203-312.

DEVAS, R. P. C. 1943. Birds of Grenada, St. Vin-cent and the Grenadines (British West Indies). Advocate Co., Ltd., Barbados.

KEITH, A. R. 1997. The birds of St. Lucia. British Ornithologists’ Union Check-list No. 15.

LECK, C. F., AND R. L. NORTON. 1991. An anno-tated checklist of the birds of the U. S. Virgin Islands. Antilles Press, Christiansted, St. Croix.

NOL, E., AND R. C. HUMPHREY. 1994. American Oystercatcher (Haematopus palliatus). In The birds of North America, no. 82 (A. Poole and F. Gill, eds.). Academy of Natural Sciences, Phila-delphia; American Ornithologists’ Union, Wash-ington, DC.


WELLS, J. G. 1902. Birds of the island of Carriacou. Part I. Water birds. Auk 19:237-246.



HISPANIOLAN LIZARD-CUCKOO (COCCYZUS LONGIROSTRIS) TETHERED BY COMMON GREEN SNAKE (UROMACER CATESBYI)

THOMAS H. WHITE, JR.

Department of Zoology, North Carolina State University, Raleigh, NC 27695; current address: U.S. Fish and

Wildlife Service, Rio Grande Field Office, PO Box 1600, Rio Grande, Puerto Rico 00745; e-mail:

[email protected] Abstract: Entanglement of birds by snakes is rarely reported. On 15 July 1998, a Hispaniolan Lizard-Cuckoo (Coccyzus longirostris) was encountered tethered to a small sapling by common green snake (Uromacer catesbyi), which apparently was the intended prey of the cuckoo, in Parque Nacional del Este, Dominican Republic. Key words: Coccyzus longirostris, ensnarement, green snake, Hispaniolan Lizard Cuckoo, Uromacer catesbyi Resumen: UN PÁJARO BOBO MAYOR (COCCYZUS LONGIROSTRIS) ENTRAMPADO POR UNA SERPIENTE VERDE COMÚN (UROMACER CATESBYI ). El entrampe de aves por serpientes es raramente registrado. El 15 de julio de 1998, un Pájaro Bobo Mayor (Coccyzus longirostris) fue encontrado sujeto a un pequeño arbusto por una serpiente verde común (Uromacer catesbyi), la cual aparentemente era una presa pretendida por el pájaro, en el Parque Nacional del Este, República Dominicana. Palabras clave: Coccyzus longirostris, entrampe, serpiente verde, Arriero de la Española, Uromacer catesbyi

Résumé : PRISE AU PIEGE D’UN TACCO D’HISPANIOLA (COCCYZUS LONGIROSTRIS) PAR UN SERPENT VERT ARBORI-

COLE (UROMACER CATESBYI). L’enchevêtrement d’oiseaux avec des serpents est rarement observé. Un Tacco d’His-paniola (Coccyzus longirostris) a été trouvé le 15 juillet 1998 dans le Parc National del Este, en République Domini-caine, attaché à un arbuste par un serpent vert arboricole (Uromacer catesbyi), qui était probablement sa proie. Mots-clés : Coccyzus longirostris, prise au piège, serpent vert, Tacco d’Hispaniola, Uromacer catesbyi

ALTHOUGH BIRDS have been reported ensnared or entangled in a variety of items, this occurs most often with plants. For example, over 12 species of small Passerines have been found entangled in seed heads of burdock (Arctium minus; McNicholl 1988,1994). Lincoln (1931) reported entanglement in string or nesting material as the cause of 11 (0.9%) of 1,136 documented avian mortalities. In Mississippi, Samano et al. (1998) reported the fatal ensnarement of four endangered Red-cockaded Woodpeckers (Picoides borealis) and a Yellow-bellied Sapsucker (Sphyrapicus varius) in mesh snake traps used to prevent snake predation at Red-cockaded Woodpecker nest sites. In Costa Rica, Graham (1997) reported the fatal entanglement of hermit hummingbirds (Phaethornis spp.) in spider webs. There has been at least one reported instance of a bird entangled by a snake. In Arkansas, Me-shaka et al. (1988) reported an immature Red-shouldered Hawk (Buteo lineatus) that was stran-gled by a black rat snake (Elaphe o. obsoleta) it had captured until both were rescued. Here I report the ensnarement of a Hispaniolan Lizard-Cuckoo (Coc-

cyzus longirostris) by a common green snake (Uromacer catesbyi).

OBSERVATIONS On 15 July 1998, while conducting radiotel-emetry of Hispaniolan Parrots (Amazona ventralis) in Parque Nacional del Este, Dominican Republic, I encountered an adult Hispaniolan Lizard-Cuckoo struggling vigorously with a 0.5-m long Uromacer

catesbyi, which the cuckoo had partially ingested. As I approached, the cuckoo attempted several times to take flight. However, before dying the snake had tightly coiled approximately 5 cm of its tail around a small sapling. Because the cuckoo apparently could neither disgorge nor dislodge the now-dead snake, the bird was effectively tethered to the tree. I easily captured the frantically struggling cuckoo by hand and carefully extracted the snake, of which 5 cm had been swallowed, from the cuckoo. It appeared that the head of the snake, being slightly broader than the anterior portion of the body, was primarily the cause of the entrapment as I distinctly felt friction while extracting it. I examined the cuckoo for apparent external injuries and found none. No blood was observed in the bird’s mouth nor did the bird’s throat appear injured from the encounter. I then photographed the cuckoo and, when released, it immediately flew away.


LITERATURE CITED ABREU, D., AND K. A. GUERRERO (eds). 1997.

Evaluacion ecológica integrada Parque Nacional del Este, República Dominicana. Tomo 1: Recur-sos terrestres. The Nature Conservancy, Arling-ton, VA.

GRAHAM, D. L. 1997. Spider webs and windows as potentially important sources of hummingbird mortality. Journal of Field Ornithology 68:98-101.

LINCOLN, F. C. 1931. Some causes of mortality among birds. Auk 48:536-546.

MCNICHOL, M. K. 1988. Bats and birds stuck on burdock. Prairie Naturalist 20:157-160.

MCNICHOL, M. K. 1994. Additional records of birds caught on burdock. Ontario Birds 12:117-119.

MESHAKA, W. E., S. E. TRAUTH, AND C. FILES. 1988. Elaphe obsoleta obsoleta (black rat snake). Antipredatory behavior. Herpetological Review 19:84.


SAMANO, S., D. R. WOOD, J. COLE, F. J. VILELLA, AND L. W. BURGER. 1998. Red-cockaded Wood-peckers ensnared in mesh snake traps. Wilson Bulletin 110:564-566.

DISCUSSION I am unsure of exactly how long the cuckoo had been held in such manner. However, it certainly was not present when I had passed the same site 2 hr earlier. Although it is unknown whether the cuckoo would have died as result of this incident, the pres-ence of mongooses (Herpestes javanicus), feral cats (Felis silvestris catus) and the hot, dry climate of the area (Abreu and Guerrero 1997) certainly placed the bird in dire jeopardy under the circumstances. This appears to be the first reported case of a preda-tory bird actually tethered to a tree by its intended prey. According to Raffaele et al. (1998), birds of this genus (Coccyzus spp.) commonly consume small reptiles such as snakes, and events of this na-ture may constitute a previously unknown, albeit rare, potential source of mortality for these birds.

ACKNOWLEDGMENTS I thank W. J. Arendt, W. K. Hayes, and S. C. Latta for reviewing an earlier version of this note, North Carolina State University and the U. S. Fish and Wildlife Service for financial and logistic sup-port during the time that these observations were made, and F. Brammer and K. G. Smith for pointing out pertinent references. Special thanks are also due Parque Nacional del Este for study area access, and also to Jesus Almonte and Jose Luis Hernandez for assistance in the field.

WHITE — COCCYZUS LONGIROSTRIS TETHERED BY A SNAKE



FIRST RECORD OF AUDUBON’S WARBLER (DENDROICA CORONATA AUDUBONI) IN JAMAICA

GARY R. GRAVES

Department of Vertebrate Zoology, MRC-116, National Museum of Natural History, Smithsonian Institution,

P.O. Box 37012, Washington, D. C. 20013-7012, USA; e-mail: [email protected]

Abstract: I observed and photographed an “Audubon’s” Warbler (Dendroica coronata auduboni) in Kingston, Jamaica, in December 2005. This is the first well-documented record of the auduboni population complex of the Yellow-rumped Warbler (Dendroica coronata) in Jamaica and the Caribbean. Key words: “Audubon’s” Warbler, Caribbean, Dendroica coronata auduboni, Jamaica, Yellow-rumped Warbler Resumen: PRIMER REGISTRO DE LA BIJIRITA DE AUDUBON (DENDROICA CORONATA AUDUBONI) EN JAMAICA. Se observó y fotografió una Bijirita de Audubon (Dendroica coronata auduboni) en Kingston, Jamaica, en diciembre del 2005. Este es el primer registro bien documentado del complejo poblacional auduboni de la Bijirita Coronada (Dendroica coronata) en Jamaica y el Caribe. Palabras clave: Bijirita Coronada, Bijirita de Audubon, Caribe, Dendroica coronata auduboni, Jamaica

Résumé : PREMIERE OBSERVATION DE PARULINE D’AUDUBON (DENDROICA CORONATA AUDUBONI) EN JAMAÏQUE. J’ai observé et photographié en décembre 2005 une Paruline « d’Audubon » (Dendroica coronata auduboni) à King-ston en Jamaïque. C’est la première observation bien documentée d’un individu du complexe d’espèce auduboni de la Paruline à croupion jaune (Dendroica coronata) en Jamaïque et dans la Caraïbe. Mots-clés : Paruline “d’Audubon”, Caraïbe, Dendroica coronata auduboni, Jamaïque, Paruline à croupion jaune

THE AUDUBONI GROUP of populations of the Yel-low-rumped Warbler (Dendroica coronata) breeds in western North America from British Colombia south through the mountains of the western United States to Durango, Mexico (American Ornitholo-gists’ Union 1957, Dunn and Garrett 1997). The auduboni group winters commonly in the western United States from California, Arizona, and New Mexico southward through western and highland Mexico and sparsely south to Honduras. Individuals with auduboni plumage characteristics occur casu-ally in eastern North America south to Florida. The only previous report of auduboni in the Caribbean was an inadequately documented sight record from Providenciales, Turks and Caicos Islands (Aldridge 1987). In this note I photographically document the first record for the Caribbean in Jamaica. On 19 December 2005, I observed and photo-graphed an “Audubon’s” Warbler (Dendroica coro-

nata auduboni) in Hope Botanical Gardens, King-ston, Jamaica (18°01.34’N, 76°44.95’W; WGS-84). The warbler, which appeared to be a male in first basic plumage, was studied through binoculars (Zeiss, 10×40) at close range (6-8 m) in good morn-ing light for about 5 min (08:45-08:50 hr). The war-bler was similar in appearance to a male “Myrtle” Warbler (Dendroica c. coronata) observed earlier

that morning, but differed in possessing a bright yellow throat and in lacking a pale supraloral streak and superciliary (Fig. 1). The warbler’s distinctive call note was sharper than those of nearby “Myrtle” Warblers. The photo-documentation represents the first record of the auduboni population complex of the Yellow-rumped Warbler (Dendroica coronata) in Jamaica. Brian Schmidt, Ricardo Miller, and I relocated and photographed the “Audubon’s” Warbler at close range (6-10 m) for more than 1 hr on 20 De-cember (08:30-09:30 hr). It associated closely with several “Myrtle” Warblers, part of a mixed-species flock that frequented three enormous trees (Enterlobium cyclocarpum) growing on the mowed lawn. This introduced tree is seasonally deciduous and the pinnately-compound foliage preferred by the warblers was beginning to abscise. In addition to the “Audubon’s” Warbler and “Myrtle” Warbler, the loosely organized flock included Northern Pa-rula (Parula americana), Magnolia Warbler (D.

magnolia), Cape May Warbler (D. tigrina), Black-throated Blue Warbler (D. caerulescens), Yellow-throated Warbler (D. dominica), Prairie Warbler (D.

discolor), Palm Warbler (D. palmarum), and Ameri-can Redstart (Setophaga ruticilla). Schmidt and I returned with Catherine Levy and several other


Fig. 1. “Audubon’s” Warbler in Hope Botanical Gardens, Kingston, Jamaica, 20 December 2005. Photos by Brian K. Schmidt. See pdf file for color.

observers on 21 December and watched the warbler forage in the Enterlobium trees for another 2 hr (07:30-09:30 hr). The species composition of the flock was unchanged from the previous morning but the number of “Myrtle” Warblers had increased significantly (four to 15 individuals) suggesting the overnight arrival of migrants. The number of “Myrtle” Warblers in the area dwindled to two indi-viduals by the morning of 22 December and the “Audubon’s” Warbler could not be located. “Myrtle” Warblers exhibit an irruptive abundance pattern in Jamaica and are rare or absent in King-ston during many winters (e.g., 2003-2004). The correlative evidence suggests that the auduboni in-dividual was associated with the pulse of “Myrtle” Warblers that passed through the Kingston area in mid-December 2005.

ACKNOWLEDGMENTS I thank Catherine Levy and Susan Koenig for comments on the manuscript, Brian Schmidt for photographing the bird, and the James Bond and Alexander Wetmore funds of the Smithsonian Insti-tution for support.

LITERATURE CITED

ALDRIDGE, B. M. 1987. Sampling migratory birds and other observations on Providenciales Islands B. W. I. North America Bird Bander 12:13-18.

AMERICAN ORNITHOLOGISTS’ UNION. 1957. Check-list of North American birds. 5th ed. American Ornithologists’ Union, Baltimore, MD.

DUNN, J. L., AND K. L. GARRETT. 1997. A field guide to the warblers of North America. Hough-ton Mifflin Company, Boston, MA.

GRAVES — DENDROICA CORONATA AUDUBONI IN JAMAICA


GREATER ANTILLEAN GRACKLE (QUISCALUS NIGER) PREYS ON ANOLIS GRAHAMI

GARY R. GRAVES

Department of Vertebrate Zoology, MRC-116, National Museum of Natural History, Smithsonian Institution,

P.O. Box 37012, Washington, D. C. 20013-7012, USA; e-mail: [email protected]

Abstract: A female Greater Antillean Grackle (Quiscalus niger) was observed to dismember and consume a large male Anolis grahami in Kingston, Jamaica. The entire dismemberment sequence lasted 57 minutes. The large size of the anole indicates that the geographically-widespread grackle may be capable of preying on all size classes of the seven Jamaican Anolis species, with the possible exception of adult male Anolis garmani, the largest species on the island. This observation also suggests that individual grackles may exhibit handedness. Key words: Anolis grahami, Caribbean, Greater Antillean Grackle, Jamaica, predation, Quiscalus niger Resumen: EL CHICHINGUACO (QUISCALUS NIGER) DEPREDANDO ANOLIS GRAHAMI. Una hembra de Chichinguaco (Quiscalus niger) fue observada desmembrando y consumiedo un gran macho de Anolis grahami en Kingston, Ja-maica. La secuencia completa duró 57 minutos. El gran tamaño del lagarto indica que esta ave, ampliamente dis-tribuida es capaz de depredar todas las tallas de las siete especies de Anolis de Jamaica, con la posible excepción de los machos adultos de Anolis garmani, la mayor de las especies de la isla. Esta observación también sugiere que Quiscalus individuales pueden tener lateralidad. Palabras clave: Anolis grahami, Caribe, Chichinguaco, depredación, Jamaica, Quiscalus niger

Résumé : LE QUISCALE NOIR (QUISCALUS NIGER) EST UN PREDATEUR DE ANOLIS GRAHAMI. Une femelle de Quis-cale noir (Quiscalus niger) a été observée en train de démembrer et de consommer un grand mâle d’Anolis grahami

à Kingston en Jamaïque. La durée complète du démembrement a été de 57 minutes. La grande taille de cet anolis confirme que ce quiscale à large aire de répartition est capable de capturer toutes les classes de taille des sept espèces d’Anolis jamaicains, à l’exception, peut-être, du mâle adulte de l’Anolis garmani, la plus grande espèce de l’île. Cette observation suggère aussi que des individus de quiscales peuvent montrer une certaine adresse “manuelle”. Mots-clés : Anolis grahami, Caraïbe, Jamaïque, prédation, Quiscalus niger, Quiscale noir

AVIAN PREDATION may exert strong selection on body size and behavior of Anolis lizards in the Car-ibbean (Schoener 1979), yet the guild of anole predators on each island and the size range of anoles taken by particular avian species are virtually un-known (Lack 1976, Wunderle 1981). Athough a few dietary studies of anole predators have been con-ducted (Wetmore 1916, McLaughlin and Roughgar-den 1989, Gassett et al. 2000), predation data typi-cally accumulate as anecdotes such as the one I re-port here. On 11 February 2004, Brian Schmidt and I ob-served a female Greater Antillean Grackle (Quiscalus niger) consume a large male Anolis gra-

hami in Hope Botanical Garden, Kingston, Jamaica (18o01.30’N, 76o44.89’W; WGS-84). The geo-graphically-widespread grackle is known to feed on a wide range of animal and plant foods (Gosse 1847, Wetmore 1916). Although a comprehensive dietary study of Jamaican populations has yet to be conducted, grackle stomachs (n = 74) examined in Puerto Rico contained earwigs, beetles, weevils,

cicadas, stinkbugs, mole crickets, grasshoppers, crickets, lepidopteran caterpillars, wasps, ants, ticks, and snails, as well as fruit, seeds, and corn (Wetmore 1916). Vertebrate remains included frogs (Leptodactylus sp. and Eleutherodactylus sp.), small anoles (Anolis sp.), and ameiva lizards (Ameiva

exsul). Our Jamaican observation was noteworthy for

several reasons. First, it suggests that the Greater Antillean Grackle is capable of preying upon all size classes of the seven Jamaican Anolis species with the possible exception of adult males of the largest species, A. garmani. Secondly, the observa-tions provide insight on the behavioral techniques used by grackles to dismember large, tough prey items. Finally, the anecdote suggests that individual grackles may exhibit handedness. The bulk of this report addresses the behavioral aspects with a par-ticular emphasis on the sequence of events. The grackle emerged from a palm grove and car-ried the anole in its bill to a low tree overhanging the main road through the garden. The grackle was



thought to be a female because it had glossy plum-age but lacked the distinctive keeled tail characteris-tic of males. The anole was limp and undamaged except for an obvious head wound, which I assumed was inflicted by the grackle. The grackle held the anole against the branch with its left foot and vigor-ously grasped and then wrenched and pulled frag-ments of skull, muscle, and then the fleshy tongue, through the anole’s gaping mouth, leaving the skin of the cranial region flaccid. The grackle then crushed and mashed the anole’s forelimbs by run-ning them back and forth through its mandibles, and afterwards grasped and jerked, but failed to detach, the anole’s toes. The procedure was repeated on the hind limbs without visible success. The distal half of the anole’s tail was then torn free and crushed by passing it back and forth through the grackle’s man-dibles before it was swallowed. The grackle paused a few seconds while the tail fragment settled in its stomach and then grasped and jerked large pieces of flesh from the tail stump. The grackle flipped the anole several times and picked tissue from its neck region until the orange dewlap was torn half away. The grackle then pene-trated the visceral cavity by pecking and enlarging the anole’s cloacal opening. After extracting and consuming the intestines, the grackle made another unsuccessful attempt to tear away the forelimbs and pectoral girdle. The grackle was hidden from view behind foliage for several minutes. When it reap-peared, the skin of the anole’s back exhibited a large tear. In short order, the grackle consumed the remaining viscera and began ripping away the trunk musculature. The hind limbs were ripped free from the inside and skinned down to the metatarsals by pulling on the free end of the limbs. The vertebral column was completely stripped of loose muscle tissue and then dropped to the ground. The remain-der of the carcass was torn in two pieces. The skinned hind limbs of the anole dangled from a long strip of skin held by the grackle’s left foot, whereas the anole’s pectoral girdle and forelimbs were held to the perch with its right foot. During the observa-tion period, the grackle made several short flights (1-2 m) with the anole in its bill. Although the grackle’s right foot appeared to be fully functional, the bird invariably anchored the anole with its left foot, which seemed to indicate handedness (Vince 1964, Clark 1973, Knox 1983). In one of the more noteworthy maneuvers, the grackle grasped the dangling skin with its bill and pulled the suspended hind limbs toward the tree limb, anchored the loop of skin with its left foot,

and then grasped the hind limbs directly with its bill. Only a dozen or so species of birds have been previously recorded pulling suspended food up to a perch (Thorpe 1963, Heinrich 1995). The grackle picked some additional bits of flesh from the hind limbs but finally left the remnants of skin and bone wrapped around the branch. The pectoral girdle and forelimbs were then dropped, perhaps inadvertently, because the grackle tilted its head and peered down-ward toward the scrap. The grackle paused only momentarily before it began searching a nearby clump of Tillandsia in the canopy. The entire dis-memberment sequence lasted 57 minutes. Based upon measurement of the recovered fore-limbs, the snout-vent length of the anole was ~70 mm (body mass, ~9-12 g), which is near the maxi-mum size recorded for male Anolis grahami

(Schoener and Schoener 1971). This indicates that female grackles (body mass; 0 = 76.0 ± 4.5 g, n = 11; S. Koenig, unpubl. data) are capable of preying on all size classes of the small to medium-sized Anolis species (grahami, opalinus, valencienni,

lineatopus, sagrei, reconditus) known from Jamaica (Rand 1967, Schoener and Schoener 1971). On the other hand, male grackles (body mass; 0 = 107.7 ± 8.0 g, n = 11; S. Koenig unpubl. data) may be able to prey on the largest Jamaican species, A. garmani, with the possible exception of adult males (snout-vent length ~ 110 mm).

ACKNOWLEDGMENTS

I thank James Schulte for confirming the identity of the anole with cytochrome b gene sequence data (Genbank accession number DQ353945), Susan Koenig for providing body mass data for grackles, Brian Schmidt for field assistance, and William Hayes, Catherine Levy, and Douglas McNair for comments on the manuscript. Research permits were granted by National Environment and Plan-ning Agency, Kingston.

LITERATURE CITED CLARK, G. A. 1973. Holding food with the feet in

passerines. Bird-Banding 44:91-99. GASSETT, J. W., T. H. FOLK, K. J. ALEXY, K. V.

MILLER, B. R. CHAPMAN, F. L. BOYD AND D. I. HALL. 2000. Food habits of Cattle Egrets on St. Croix, U. S. Virgin Islands. Wilson Bulletin 112:268-271.

GOSSE, P. H. 1847. The Birds of Jamaica. Bentley, Wilson and Fley, London.

HEINRICH, B. 1995. An experimental investigation of insight in Common Ravens (Corvus corax).

GRAVES — QUISCALUS NIGER PREYS ON ANOLIS GRAHAMI


Auk 112:994-1003. KNOX, A. G. 1983. Handedness in crossbills Loxia

and the Akepa Loxops coccinea. Bulletin of the British Ornithologists’ Club 103:114-118.

LACK, D. 1976. Island biology, illustrated by the land birds of Jamaica. University of California, Berkeley.

MCLAUGHLIN, J. F. AND J. ROUGHGARDEN. 1989. Avian predation on Anolis lizards in the north-eastern Caribbean: an inter-island contrast. Ecol-ogy 70:617-628.

RAND, A. S. 1967. The ecological distribution of the anoline lizards around Kingston, Jamaica. Bre-viora 272:1-18.

SCHOENER, T. W. 1979. Inferring the properties of

predation and other injury-producing agents from injury frequencies. Ecology 60:1110-1115.

SCHOENER, T. W. AND A. SCHOENER. 1971. Struc-tural habitats of West Indian Anolis lizards I. Lowland Jamaica. Breviora 368:1-53.

THORPE, W. H. 1963. Learning and instinct in ani-mals. Methuen and Company, London.

VINCE, M. A. 1964. Use of the feet in feeding by the Great Tit Parus major. Ibis 106:508-529.

WETMORE, A. 1916. Birds of Porto Rico. United States Department of Agriculture Bulletin 326:1-140.

WUNDERLE, J. M. 1981. Avian predation upon Ano-

lis lizards on Grenada, West Indies. Herpetolo-gica 37:104-108.

GRAVES — QUISCALUS NIGER PREYS ON ANOLIS GRAHAMI

Puerto Rican Parrot (Amazona vittata) Drawing by Tirtsa Porrata-Doria


PRIMER REGISTRO SOBRE LA REPRODUCCIÓN DEL OSTRERO AMERICANO (HAEMATOPUS PALLIATUS) EN CUBA

ERNESTO HERNÁNDEZ PÉREZ

Refugio de Fauna “Lanzanillo-Pajonal-Fragoso”, Empresa Nacional para la Protección de la Flora y la Fauna,

Cuba Resumen: Se documenta por primera vez la presencia de una pareja de Ostreros Americanos (Haematopus pallia-

tus) criando en el archipiélago cubano. La observación tuvo lugar en cayuelo del Mono, ubicado en el Refugio de Fauna Lanzanillo-Pajonal-Fragoso, provincia Villa Clara. La pareja se encontró activa desde el día 18 Abril 2005, y mostró conductas de distracción ante depredadores frente a los investigadores. El día 29 Junio 2005 se encontró un pichón volantón, de 460 g de peso, largo total 370 mm, ala extendida 340 mm, largo del tarso 64 mm y largo del pico 69 mm. Palabras clave: Cuba, Haematopus palliatus, Ostrero Americano, reproducción

Abstract: FIRST BREEDING RECORD OF THE AMERICAN OYSTERCATCHER (HAEMATOPUS PALLIATUS) IN CUBA. We document the first breeding record of a pair of American Oystercatchers (Haematopus palliatus) in Cuba. Our ob-servations occurred in Cayuelo del Mono, Lanzanillo-Pajonal-Fragoso Wildlife Refuge, in Villa Clara province. The pair was seen from 18 April 2005, displaying antipredator behavior when approached by the research team. On 29 June 2005, we found a fledgling with body mass of 460 g, total length of 370 mm, wing length of 340 mm (flattened and straightened), tarsus of 64 mm, and culmen of 69 mm. Key words: American Oystercatcher, breeding, Cuba, Haematopus palliatus Résumé : PREMIÈRE OBSERVATION DE NIDIFICATION DE L’HUÎTRIER D’AMÉRIQUE (HAEMATOPUS PALLIATUS) À CUBA. Nous avons observé le premier couple nicheur d’Huîtrier d’Amérique (Haemotopus palliatus) de Cuba. L’ob-servation a été faite à Lanzanillo-Pajonal-Fragoso Wildlife Refuge, dans la province de Villa Clara. Le couple a été vu du 18 avril 2005, adoptant un comportement d’éloignement des prédateurs quand il était approché par l’équipe de recherche. Nous avons trouvé le 29 juin 2005, un oisillon de 460 g, de longueur totale de 370 mm, avec une lon-gueur d’aile de 340 mm (aplatie et étendue), un tarse de 64 mm et un bec de 69 mm. Mots-clés : Cuba, Haematopus palliatus, Huîtrier d'Amérique, nidification

EL OSTRERO AMERICANO (Haematopus palliatus) es uno de los 11 representantes de la familia Hae-matopodidae (Hockey 1996). En el Caribe se consi-dera localmente común en las Bahamas, Puerto Ri-co, Islas Vírgenes y Guadalupe (Raffaele et al. 1998). En Cuba se reconoce como un residente in-vernal muy raro, con tres observaciones documenta-das en las localidades de Coco, Paredón Grande y las ciénagas de Zapata, en los meses de septiembre, octubre y enero, respectivamente (Garrido y Kirk-connell 2000). El 18 de abril de 2005, durante las actividades de monitoreo de aves marinas realizada por el personal del Refugio de Fauna Lanzanillo-Pajonal-Fragoso, se observó una pareja de Ostrero en Cayuelo del Mono. Este pequeño cayo de 89 m de largo y 60 m de ancho, es un montículo de piedra plano (1 m sobre el nivel del mar) que aflora a unos 1 500 m al Este-nordeste de Punta del Pino, Cayo Pajonal. Su vegetación es muy escasa, solo un árbol de Mangle Prieto (Avicennia germinans) y vegetación halófita que crece sobre la roca caliza. Esta localidad consti-

tuye un sitio de nidificación de la Gaviota Monja (Sterna anaethetus), la Gaviota de Sándwich (S.

sandvicensis) y la Gaviota Común (S. hirundo), así como del Títere Playero (Charadrius wilsonia). Durante los tres días de expedición la pareja de ostreros se mantuvo en la localidad, mostró conduc-tas de distracción de depredadores cuando los espe-cialistas recorrían el cayuelo; específicamente, vola-ron alrededor del cayuelo mientras emitían un fuerte silbido, para luego posarse en sitios más apartados. Debido al comportamiento de la pareja y al mes en que fue observado (abril, que coincide con la etapa reproductiva de la especie), se consideró la posibilidad de que criaran en el cayuelo y se proce-dió a localizar e identificar el nido. Se halló un nido con tres huevos que, inicialmente se atribuyó al Ostrero, pues no se encontró otra ave en el lugar. En la segunda visita (2 de junio del 2005), se comprobó que el nido pertenecía a una pareja de Títere Playe-ro. En esta fecha ya habían comenzado a nidificar la Gaviota de Sándwich y la Gaviota Común, por lo que las tareas de búsqueda del nido de Ostrero



yen a esta especie dentro de las aves nidificantes en el territorio (Garrido y Kirkconnell 2000, Blanco et

al. 2001). La observación de una pareja de Ostrero en Cayuelo del Mono y el posterior hallazgo del pichón, adiciona una especie más a la lista de aves de orilla nidificantes de Cuba.

AGRADECIMIENTOS Este trabajo forma parte de los resultados del pro-yecto para el estudio de las Aves acuáticas y de lito-ral, llevado a cabo en el Refugio de Fauna Lanzani-llo-Pajonal-Fragoso. Reconocimientos especiales a los participantes de las expediciones René E Torres Sierra, Nelson E Montenegro Calderón, Raúl Fer-nández Rodríguez, Michael Fernández, José R Lar-go Pérez, Iván Nápoles Pérez, Jorge A Gonzáles Acosta, Osmani Sardá Reyes, Alberto Gutiérrez Carvajal y Tomás Camacho Truit.

LITERATURA CITADA BLANCO, P., S. PERIS, Y B. SÁNCHEZ. 2001. Las

aves limícolas (Charadriiformes) nidificantes de Cuba: distribución y reproducción. Centro Iberoa-mericano de la Biodiversidad, Alicante, España.

GARRIDO, O. H., Y A. KIRKCONNELL. 2000. Field guide of the birds of Cuba. Cornell University Press, Ithaca, NY.

GUNDLACH, J. 1893. Ornitología Cubana. Catalogo Habana, Impresa La Moderna, Habana.

HOCKEY, P. A. R. 1996. Family Haematopodidae (oystercatchers). Pp. 308-325 en J. del Hoyo, A. Elliot, y J. Sargatal (eds.), Handbook of the birds of the World. Vol. 3. Hoatzin to auks. Lynx Edi-cions, Barcelona.

RAFFAELE, H., J. WILEY, O. GARRIDO, A. KEITH, Y J. RAFFAELE. 1998. A guide to the birds of the West Indies. Princeton University Press, Prince-ton, NJ.

fueron pospuestas temporalmente para no afectar al resto de la comunidad de aves que crían en el ca-yuelo. En una tercera visita, el 29 Junio 2005, se localizó en el extremo este del cayuelo un pichón volantón de Ostrero. El ave se encontró oculta en el diente de perro, muy cercano al rompiente de las olas. Fue capturada y se le realizaron mediciones morfométri-cas, obteniéndose como resultado un peso de 460 g, largo total 370 mm, ala extendida 340 mm, largo del tarso 64 mm y largo del pico 69 mm. En este estado de desarrollo presentó una coloración marrón claro en el dorso y blanco en la región ventral, el pico rojo oscuro por encima, anaranjado ó rojo pálido por debajo con el extremo distal negro, patas rosado claro y el aro orbital sin el rojo intenso que presen-tan los adultos. En los humedales cubanos las especies que com-ponen al grupo de las aves de orilla son numerosas y abundantes durante el periodo no reproductivo, pero hasta el momento solo se conocía de seis espe-cies que utilizan el territorio nacional como área de cría: Jacana spinosa, Himantopus mexicanus, Cha-

radrius alexandrinus, C. wilsonia, C. vociferus y

Catoptrophorus semipalmatus (Blanco et al. 2001). No se conoce ninguna referencia bibliográfica pre-via que confirme la nidificación del Ostrero en Cu-ba; sin embargo, algunos autores realizaron obser-vaciones sobre este aspecto. Por ejemplo, Gundlach (1893) realizó la siguiente anotación referente a la reproducción de la especie en Cuba: “Habiendo visto la especie en los distintos meses del año, julio, septiembre, enero, etc., supongo que anidará en los cayos, pero nada he podido observar sobre su propa-gación”. Por otro lado, Raffaele et al. (2000) inclu-yó a Cuba como uno de los posibles sitios de repro-ducción de la especie en las Antillas Mayores. Con-trario a estas dos referencias, las publicaciones re-cientes realizadas por ornitólogos cubanos no inclu-

HERNÁNDEZ PÉREZ — REPRODUCCIÓN DEL HAEMATOPUS PALLIATUS EN CUBA

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the significance of bonaire, netherlands antilles, as a breeding

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