seabird monitoring field guide - caribbean seabirds fieldguide.pdf · 22 little camanoe 23 little...

Seabird Monitoring

Field Guide

A field guide to monitoring seabirds in the

British Virgin Islands, West Indies

Seabird Monitoring Field Guide

Why count seabirds....................................................2

What to count and where…........................................3-4

When to count............................................................5

How to count..............................................................6

Summer breeding seabirds.........................................7-10

Winter/asynchronous breeding seabirds...................11-13

Recording ............................. .....................................14

Sample recording form...............................................15

This field guide was produced as part of the Darwin Plus project

Using Seabirds for Caribbean Marine Planning. The project was led

by the University of Liverpool in partnership with the Royal

Society for the Protection of Birds (RSPB), Jost Van Dykes

Preservation Society and BVI National Parks Trust, with support

from the BVI Government’s Department of Conservation &

Fisheries.


Contents Why count seabirds

Citation: Soanes LM, Zaluski S, Bright JA & Green JA (2014) Seabird Monitoring

Field Guide: A field guide to monitoring seabirds in the British Virgin Islands.

Jost Van Dykes Preservation Society. BVI , West Indies.

3


Contents

2

Why count seabirds

The British Virgin Islands are home to 15 breeding seabird

species, with two populations reported as being of global

importance and 8 populations as regionally important.

As top marine predators, seabirds are an important indicator

of the health of the marine ecosystem as a whole. Regular

and repeatable counts are crucial to monitor populations,

assess their health and target conservation action

Map of British Virgin Islands (see table on next page for island names)

What to count and where?


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1 Anegada

2 Beef Island

3 Broken Jerusalem

4 Carrot Rock

5 Carval Rock

6 Cistern Rock

7 Cockroach Island

8 Cooper Island

9 Deadmans Chest

10 East Seal Dog

11 Eustatia

12 Fallen Jerusalem

13 George Dog

14 Ginger Island

15 Great Camanoe

16 Great Dog

17 Great Thatch

18 Great Tobago

19 Green Cay

Previously recorded breeding species on each of BVI’s

islands and cays. NOTE this list is not exhaustive, and

colonies move between years, particularly tern species

5

4 Seabird Monitoring Field Guide

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20 Guana Island

21 Jost Van Dyke

22 Little Camanoe

23 Little Jost Van Dyke

24 Little Thatch

25 Little Tobago

26 Marina Cay

27 Mosquito Island

28 Necker Island

29 Norman Island

30 Pelican Island

31 Peter Island

32 Prickly Pear

33 Round Rock

34 Salt Island

35 Sandy Cay

36 Sandy Spit

37 Scrub Island

38 The Indians

39 Tortola

40 Virgin Gorda

41 Watsons Rock

42 West Dog

43 West Seal Dog

When to count?

Yellow indicates months when breeding may occur, ticks indicate best time to survey, some asynchronous species will require two counts per year


J F M A M J J A S O N D

Brown booby

Magnificent

frigatebird

Red-billed

tropicbird

White-tailed

tropicbird

Brown pelican

Laughing gull

Sooty tern

Bridled tern

Royal tern

Roseate tern

Sandwich tern

Least tern

Brown noddy

Audubon’s

shearwater

7

BOAT-BASED COUNTS

Given the large number of cays to survey and the inaccessibility of

most within the British Virgin Islands, the easiest way to survey is by

boat

Circumnavigate each island slowly ideally between 06:00-10:00

or 15:30-18:00 to coincide with peak seabird activity

Record number of adults associated with the colony (e.g. landing

in colony, territorial behaviour displays, carrying fish)

Do not record those that appear just to be feeding close to or

flying past the island

LAND-BASED COUNTS

Actual counts of Apparently Occupied Nests will provide the most

accurate population counts, so where possible islands and cays should

be surveyed by foot and nests counted

Locate seabird nesting areas by circumnavigating islands by boat

Walk in a team of three (two surveyors and one recorder)

in parallel transects throughout the colony covering all suitable

looking habitat

Record contents of nests as:

1) Incubating adult

2) Egg

3) Young chick

4) Large chick

5) Fledged chick

It is NOT necessary to record adult numbers if you are thoroughly and

systematically recording nests.

When to count? How to count

Seabird Monitoring Field Guide 6

Summer breeding seabirds - common breeders

Photo: Louise Soanes

Photo: L. Soanes


Audubon’s shearwater

Rarely observed during daylight

Leaves and returns to breeding site during darkness

Nests in crevices in rocks, under boulders and cliff edges

Ideally all suitable habitat should be searched for nests

Incubating adults often respond to call “playback”

Play male and female call for 30s every metre in suitable

habitat and listen for responses for a further 30s

Incubating adults or chicks may also be seen by looking into

crevices or under boulders

Photo: Richard Brown Photo: Richard Brown

Adult with egg Chick

9

Summer breeding seabirds - common breeders

Photo: Alan Vernon

Photo: Lawrence Scott



Laughing gull

Nests are difficult to locate and are found

on the ground, often under bushes, or in

rocky outcrops

Brown Noddy

Nest on cliff edges, under boulders and

on top of vegetation

Bridled tern

Black upper body and white underparts

Only confused with similar sooty tern

which has not been reported breeding in

BVI (white eye stripe stops at eye on

sooty tern but extends beyond on bridled

tern)

IN FLIGHT

Laughing gull Brown noddy Bridled tern

8

Photo :Henry Cook

Photo: Blundelwood

Photo: Katseye116 Photo: MJ Anderson Photo: Peter HiIl

Photo: James Kimani

Photo: Len Blumin

Roseate tern

Red legs

Black bill with red base

Long, forked tail

Length 36 cm

Sandwich tern

Black bill with yellow tip

All black forehead

Length 38 cm

Royal tern

Largest of terns

Orange bill

Shaggy crest

Length 50 cm

Least tern

Smallest breeding tern

Yellow bill

White above eye

Yellow legs

Length 23 cm

Summer breeding seabirds - common breeders Summer breeding seabirds - occasional/rare

Photo: Scott Hecter

Royal (orange bill) &

sandwich (black bill)


Photo: Scott Hecter

Photo: Lisa Lawley

11

Common tern

Similar to roseate tern but lacks deeply

forked tail and has more red on bill

Cayenne tern

Yellow bill and black crest

Gull-billed tern

Thick black bill i Black head

IN FLIGHT

Summer breeding seabirds - common breeders Summer breeding seabirds - occasional/rare

Photo: Paul Ritchie


Roseate Common Sandwich

Least Gull-billed

Royal (left) cayenne

(middle) and sandwich

Royal (non-breeding)

Photo: Paul Ritchie

Photo: Eric Houlii

Photo:USFWS

Common

Photo: Bob Devlin

Photo: J.N Stuart

10

Photo: Chrisine Fusco Photo: Haskor

Magnificent frigatebird

Breed year-round (with peaks Oct-Jan)

Sensitive to disturbance! Birds eat unattended eggs and chicks

Take series of photographs of the colony from a vantage point

on top of the ridge of Great Tobago

Open photographs on computer, mark and count apparently

occupied nests as any adult bird seen sat at colony or any

unattended chick.

Winter/ asynchronous breeding seabirds

Photo:



Photo: Susan Zaluski

Photo: Susan Zaluski Photo: Susan Zaluski


Female Breeding male

Juvenile Flying female

13

Tropicbirds

Breed year-round

Nest under boulders, in

crevices and cliff edges

Nests can often be

identified by smell or

alarm call

Red-billed tropicbird

Distinguished by red bill

and mostly white upper

parts

White tailed tropicbird

Yellow bill & bold black wing markings

For boat-based counts record birds entering cliff face during

hours of peak daily activity (from 15:30 to 17:30)


Photo: K Mccormack

12



Photo: tinyfishy

Photo: Farah Mukhida Photo: Nancy Pascoe Photo: Bonxie88

Red-billed adult Red-billed chick White-tailed adult

Brown Pelican

Count adults and chicks

A nest can contain 1-3 chicks, but can

be hard to distinguish, record total

number of chicks then report breeding

pairs as a:

minimum (if every nest had 3

chicks) and

maximum (if every nest had 1

chick)

Brown Booby

Nests on ground

Adults have brown upperparts and white underparts

Chicks white or fluffy white and brown, immature all brown

Recording data Winter/asynchronous breeding seabirds


Photo: photomatt28

Photo: Alan Vernon

Photo: Susan Zaluski Photo: Susan Zaluski Photo: Susan Zaluski

Brown booby adult Chick Juvenile

Breeding adult

Adult in flight

15

Recording data Winter/asynchronous breeding seabirds


See example recording form on back page

Use one form per species per site

Remember to write the date and site on all forms!

Record stage of breeding where possible to help plan timing

of future surveys.

For more details on seabird monitoring methods see the

EPIC Seabird Breeding Atlas (www.epicislands.org).

For previous BVI seabird surveys see McGowan et al. 2006.

Endangered Species Research 2 15-20

Contact details for Jost Van Dykes Preservation Society:

Email: [email protected]

Tel: 284 540 0861

Front cover image: Magnificent frigatebird chick by Susan Zaluski, other photos are those

freely available (when acknowledged) from Flicker (https://www.flickr.com/) under the Crea-

tive Commons license, or by local staff from the BVI (Susan Zaluski and Nancy Woodfield-

Pascoe

14

Date: Site:

Surveyors: Recorder:

Species:

Boat-based Counts: Record number of adult birds flying around/

associated with each cay (e.g. territorial behaviour, landing on, flying

close to, carrying fish to etc.

Number of adults associated

with cay

Land-based Counts: Record contents of nest whenever possible, if too

much disturbance occurs from walking in colony count number of

flushed adults in air instead.

Incubating adult

Nest with eggs

Nest with small chicks (naked or downy)

Nests with large chicks (some or all adult

feathers)

Number of flushed adults

Additional notes (e.g. Record empty or

predated nests, GPS locations etc)

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