CHAPTER V
RESULTS
HABITAT CHARACTERISTICS OF VARIOUS SITES
A total of 97 random (available) plots were sampled in all the five sites.
Table 4 gives the summary of vegetation characteristics (available) at the five study
sites.
a. Habitat Characteristics in the circular plots
There was significa~~t variation among the five sites in all the habitat
parameters (P < 0.05) except SPNO (Table 4). Multiple comparison tests,
comparing site pairs showed that plantation had significantly more number of total
trees, more number of trees in DBH classes 1 and 2, lesser number of trees in DBH
class 3, and shorter trees with lower average canopy height than the natural forest
sites excepting the Peechi (Disturbed forest) site which also had shoiter trees and
lower canopy height. Basal Area (BA) was not significantly different for any site
pairs. Within the natural forest sites, Kombazha differed from Olakara in having
less number of trees in DBH class 2 and from all other sites in having taller trees
and higher average canopy height.
Overall, the natural sites were more similar to one another than to the
plantation site which differed in most variables.
Tab
le 4
H
abita
t Cha
ract
eris
tics
of t
he
Ran
dom
ly S
elec
ted
Plo
ts in
the
Fiv
e S
tud
y S
ites
(Mea
n. S
tand
ard
Dev
lat~
on an
d R
ange
) [V
alue
s sh
arin
g th
e sa
me
lette
r wit
h~
n Col
umns
are
not
sig
n~ftc
antly
dfffe
rent
(P <
0 0
5 - N
on-p
aram
etric
Mul
tiple
Com
paris
on T
est)]
P (K
mst
al-
Wal
lis 1
-way
<
0.0
01
n.s.
< O
.Ml1
< 0
.001
<
O.(X
I1
< 0
.02
< 0
.001
<
0.0
01
DB
H 3
0.4
(+O
.SI)
(0-1
) B
1.
7 (+
0.96
) (0
-3)
A
2.4
(1.2
9)
(1-5
) A
3.1
(+ 1.
51)
(0-6
) A
2.4
(+
1.43
) (0
-5) A
Spec
ies (n)
I'lm
tatiu
n (1
7)
Dis
turb
ed
Fore
st (i
8)
Ola
kara
(18)
Kom
bazh
a (2
4)
Vaz
hani
(20)
SPN
O
5.2
(t
1.42
)
(2-7
) 5.
1 (+
1.59
)
(2-8
) 4.6
(+
1.5)
(3-9
) 4.
7 (+
1.86
)
(1 -8
) 5.
1 (+
1.94
)
(2-9
)
TR
NO
16
.8(+
5.31
) (8
-24)
B
7.4 (
+2.7
0)
(3-1
2) A
6.8
(+2
.75)
(3
-15)
A
6.6 (
+2.8
7)
(1-5
) A
7.
0 (+
2.73
) (3
-12)
A
Bas
al A
rea
(Sq
Cm
sJ
6377
.08
(+20
11.7
0)
(261
2.M
-992
9.97
) A
63
39.0
8 (+
2399
.95)
(3
00h.
34-1
1179
.64)
A
8144
.36
(+32
29.4
9)
(353
6.44
-152
08.5
5) A
95
68.2
4 (+
4626
.58)
(2
868.
74-2
2052
.83)
A
6668
.70
(+29
89.4
3)
(211
3.92
-147
47.0
3) A
DB
H 1
11
.3 (
+5.3
5)
(2-1
8) B
3.5
(+2
.W)
(0-7
) A
2.4
(+2.
15)
(0-7
) A
2.0
(+2
.64)
(0
-12)
A
2.1
(+2.
02)
(0-8
) A
DB
H 2
5.
1 (t
2.62
) (2
-10)
A
2.2
(+2.
36)
(0-7
) B
C
2.0
(1 + 1
.5 1
(0-5
) B
1.5 (
+1.1
4)
(0-4
) C
2.5 (
t 1.54
) (0
-6)
BC
lT (m)
17.0
6 (+
3.06
) (1
2.96
-24.
38)
A
17.7
9 (+
3.39
) (1
0.97
-21.
95)
A
22.6
9 (+
2.71
) (1
8.29
-25.
91)
B 24
.12
(+3.
24)
(12.
19-2
7.43
) C
21
.69
(+4.
31)
(13.
72-3
2.00
) B
AVCANHT (m
) 12
.60(
+2.4
4)
(8.6
4-16
.78)
A
13
.31
(+2.
49)
(8.7
8-17
56)
A
17-8
5 (+
2.20
) (1
3.72
-22.
86)
B
19.3
2(+2
.86)
(1
2.19
-27.
43)
C
17.8
(+3
.49)
(1
2.19
-23.
47)
BC
b. Availability of Tree Speciea and treer in the various height and
condition classen
For the purpose of analysis, nine common tree species alone were
considered. All the others were combined into a 'miscellaneous' category and all
lianas were considered as a seperate category. The tree species availability in the
various sites are given in Fig.3. There were some variations in the tree species
composition among sites. Natural forest sites had no dominant tree species (225%)
but the plantation site was dominated by Bombm and Tecrona. Miscellaneous
species constituted over 20% of trees in both the habitats.
Availability of trees in t l ie three height classes and the two condition classes
: a. fully live, and b, live with dead branches or fully dead are shown in Fig. 4 and 5
respectively for all the sites. Plantation had the smallest proportion of trees in the
tallest and partly deadldead category. Among the natural forest sites, Kombazha
had more trees in the tallest category while the disturbed forest had the least.
Vazhani had relatively low number of 'partly deadldead' hees.
Relative Abundance of Woodpeckers and other cavity nesting birds
In total, 27 diurnal cavity nesting bird species including eight woodpecker
species were recorded in all the sites combined (Appendix 1). Morphometrical
details of the eight woodpecker species are given in Table 5. Together with six owl
species and the occasional Malabar Grey Hombill (Tockus griseus) cavity nesters
constituted about 30% of the total resident avifauna of the study sites in forest
habitats (Pen. Obs.).
In 1991-92, a total of 21 species of cavity nesters including seven species of
woodpeckers w m seen in the disturbed forest hansect while the plantation m s e c t
had 23 species including eight woodpecker species (Table 6). Picur
Ta
ble
5
Mor
phom
etri
cal
det:
"s
of W
oodp
ecke
rs s
tudi
ed
1 N
sme
of
the
~~
ec
ics
l
Pygmy W
oodp
ecke
r (P
fco
rde
~
[mn
us]
nio
luce
nsi
s)
Mah
ratta
Woo
dpec
ker
(Pic
oid
es m
ahra
tren
sis)
Hea
rtsp
otte
d W
oodp
ecke
r (H
em
icir
cir
s c
an
en
re)
Yel
low
nape
d W
oodp
ecke
r (P
icu
r ch
loro
lop
hu
s)
Scal
ybel
lied
Woo
dpec
ker
(Pic
~rs
[m
yrm
eco
ph
on
eusj
xan
tho
pyg
aeu
s)
I Ruf
uous
Woo
dpec
ker
(Cel
eus
[Mic
rop
tern
irs]
bra
rhy
rru
s)
Gol
denb
acke
d W
oodp
ecke
r (D
ino
piu
m b
eng
hal
ense
)
Mal
herb
e's
gold
enba
cked
Woo
dpec
ker
(Ch
ryso
cola
pte
s 1u
crdi
r.s)
I Wei
ght (
gm
)l
1 :
Shor
t, 1
982,
and
:
Ali
and
Rip
ley,
198
3 1
M :
Mal
e an
d F
: F
emal
e
Su
mm
ary
of
the
B~
rd
C
ou
nts
I Tota
l Tra
nse
cl L
mg
fh \V
aIk
ed (
hm
s.)
To
tal N
um
be
r o
f Ca
vit
y N
est
ers
(W
oo
dp
eck
ers
)
I Tota
l Fu
mb
cr
of C
av
ity
Ne
stin
g S
peci
es
I Wo
od
pe
cke
r S
peci
es
I Woo
dp
eck
er
sig
hti
ng
pe
r h
ou
r (1
0 h
a)
I Pro
po
nio
n o
f\\o
od
pe
cke
rs
Sig
hti
ng
s
I Pro
po
rtio
n o
f B
arb
et S
igh
ting
s
I Prop
ort
ion
or
Pa
rake
en
Sig
htin
gs
I Prop
ort
ion
or O
the
r H
ole
-nest
ers
Sig
hlin
gs
Ra
tio
of S
eco
ndary
Ito
le-n
est
ers
to
Pri
ma
ry H
ole
ne
ste
rs
PL
P
lanta
llon.
DF
D
~stu
rbe
d Fore
st (P
ecc
h~
). O
K
Qla
kara
. K
O
Kom
bazh
a, V
A
Va7
ham
xanthopygaeus was not seen in the natural forest. More woodpeckers were seen in
the plantation than in the natural (disturbed) forest (Table 6; Appendix 2 and 3;
Fig.6). The number of woodpeckers seen month-wise between the two transects
was statistically significant (Mann-Whitney test, U = 61.5, p < 0.05).
The cavity nesting birds were grouped into four taxonornical classes :
Woodpeckers, Barbets, Parakeets and 'other secondary cavity nesters'. (Appendix 4
and 5; Fig. 7). There were significant differences in the overall composition of
cavity nesters at both sites ( ~ 2 = 64.268 df = 3, P < 0.001). In the plantation,
woodpeckers constituted almost twice the propomon of those in natural forest;
fewer 'other cavity nesting birds' were seen in the plantation. The composition of
the cavity-nesting groups showed sipificant month-wise variation in both sites ( ~ 2
= 68.972, df = 24, P < 0.001 for natural forest; ~2 = 107.809, df = 24, P < 0.001
for plantation). These cbanges were brought about mainly by the fluctuations in the
numbers of the frugivorous birds -parakeets and mynahs.
In 1993, the mean number of woodpeckers seen per hour (10 ha.) in the four
vansects are given in Table. 6, Appendix 6 and Fig 8. The abundance of
woodpeckers in the plantztion (6.5hr.) was comparable with that of the previous
year (6.25h.). Though natural forest sites consistently had higher sightingsh.
there were no statistical differences among the sites (H = 0.5657 [Kruskal Wallis
Test] df = 3, n.s.).
There were no significant differences among sites when the cavity nesting
assemblage was divided into four taxonomical groups as earlier (Appendix 7, Fig 8;
~2 = 15.954, df = 9, n.s.). The proporlion of woodpeckers was highest in the
plantation. The ratio of secondary cavity nesters to primary cavity nesters
(woodpecken and barbets) was consistent for plantation in both the yean ( 1 84
in 1991-92 vs. 1.85 in 1993; Table 6). Apart from Olakara (1.83), all other natural
forest sites had ratios higher than the one in plantation, ranging from 2.12 to 2.66.
FORAGMG ECOLOGY
A total of 2915 foraging observations were made on the eight woodpecker
species. The sample sizes for a species ranged from 73 (Picus xanthopygaeus) to
747 (Dinopium bengholense) (Table 7).
a. Foraging Behaviour
Based on their predominant foraging behaviours, woodpeckers were
segregated into the following groups (Short, 1978; Fig. 9): on-specialists or
gleaners - Dinopium benghalense and Celetrs brachyurus (where gleaning
constituted more than 60% of foraging activity); Specialists - Picoides moluccemis,
Chry.~ocolapres lrrcrdrrs and Hrnrrcrrcus canente (where excavation and pecking
combined accounted for 85% or more of foraging behaviour) and intermediate or
opportunists -1'rcus xanthopygaeus, Prc~rs chlorolophrrs and Picoides mohrattenvrs.
P~cus xanthopygoeus, represented by fewer samples, spent more time on ground
and besides, was found only in plantation, hence is omitted from further detailed
analysis. Foraging behaviour for all species was more or less consistent in both
habitats (Fig.9).
b. Substrate Condition
Visual examination of the plotted data (Fig 10) reveals that there were
virtually no differences among species in the use of foraging substrate condition.
Seventy percent or more of foraging was done on live substrate by all species with
the exception of the Picoides mahrottemrs which foraged more (44%) on dead
substrates in the nahual forest. There were no major differences between the two
habitats.
Table 7
Foraging Data : Number of Obseriations
PY = 1'1coides molrrccen~is; MA = P, mahratlensis; H S = Hemicrrcus ranentr; YN
= Picus chlorolophus; SB = P, xanthopygaeus; RU = Celeus brachyurus; GB =
Dinopium benghaknse; MG = Chrysocolap~es Iricidus.
Species
PY
MA
HS
YN
SB
RU
GB
MG
Total
NF = Natural Forest: PL = Plantation.
NF
267
184
188
132
131
482
286
1670
PL
237
250
66
103
73
94
265
157
1245
Total
504
434
254
235
73
225
747
443
2915
c. Substrate Size
Birds differed in their use of foraging substrate size (Fig 11). While the
smaller woodpeckers - Hemicircus canente, Picoides moluccensis, Prcoides
mahrattensis and Picus chlorolophus foraged mostly on smaller substrates ( >
50%), the larger species - Chrysocolaptes lucidus, Dinopium benghalense and
Celeus brachyurus foraged on a combination of medium and large substrates. Pair-
wise chi-square tests for species with similar foraging behaviours showed
significant differences for most pairs (Table 8). Picoides moluccensis and
Hen~icrrcus cancnle were similar in their choices of foraging substrate in both
natural forest and plantation while Picordes mahraltensis and Picus chlorolophus
were similar in the plantation. Celeus brachyurus foraged on smaller substrates
when compared to the Dinoprum benghalense in both habitats.
d. Tree DBH
There were striking differences in the woodpeckers' use of DBH classes
between the two habitats. While all species tended to use trees with larger DBH in
natural forest in greater proportion (>50%), in the plantations, trees in the medium
and small classes were used more often (>75%) (Fig. 12). This was related to the
differences in the availability of trees in the two habitats. Chi-square test results are
given in Table 8 for the pair-wise comparisons. Use of trees in the three DBH
classes was more similar in the plantation among species-pairs than in the natural
forest, where most pairs showed significant differences. The two gleaners
(Dinoprum benghalense and Celeus brachyurus) did not differ in their choice of
trees in the natural forest while in the plantation, Celeus brachyurus foraged more
on trees with small DBH than llinopium benghalense. Both Picoides mahrortensis
and Chrysocolopres lucidus chose larger DBH class trees in greater proportion
(>75%) in natural forests and used fewer trees of the small DBH class (< 5%).
6 -Y
k a 8 g S k ; =
2 : 2 B a A l 'B p - 2 5 9 B W P L .t! 3 B " 0 2 z e z b d ~ s.e 2 2 z L = 0 2 % u r n . a = ; 9 509 - U ' N 8 gE 7iz g g733 5 3 s 3 ? + L 0 2 5
.z a ¶ * Z 2 = m - 0 V l .5 2 = 5 7 5 Co r &
Table 8
Pair-wise comparisons* of Foraging Variables for Species with similar Foraging Behnviour [Chi-Square Tests]
*p values [min : p = 0.051
Natural Forest GB RU
MA - YN
MG - HS
PY - HS
PY - MG
PY = Picoides moluccensis; MA = P, mahrattensis; HS = Hemicircus canente; YN
= Picus chlorolophus; RU = Celelrs brachyurus; GB = Dinopium benghalense; MG
= Chrysocolaptes lucidus.
SUBSIZ <0.001
c0.02
<0.001
n.s.
<0.005
Plantation
DBH n.s.
<0.01
<0.001
<O.OO~
<0.03
GB - RU MA - YN
MG - HS
PY - HS
PY - MG
TRHT <0.001
n.s.
n.s.
<O.OOI
<0.05
<0.001
n.s.
<0.001
n.s.
<0.005
FORHT n.s.
n.s.
n.s.
<O.OOI
<0.005
n.s.
n.s.
n.s.
<0.001
<0.001
<0.007
n.s.
n.s.
<0.03
n.s.
<0.02
n.s.
<0.001
<0.005
n.s.
e. Tree Height
As in the case of DBH, there were differences in the tree height classes used
between the two habitats which was related to the availability (Fig 13) : all species
in natural forest used taller trees in comparison to the relatively medium-sized trees
used in the plantations. Pair-wise comparisons show that the gleaner and specialist
pairs differed significantly while the opportunist pair showed no significant
differences in either habitats (Table 8). Celeus brachyurus foraged on small and
medium sized trees consistently in both habitats.
f. Foraging Height
With the exception of the Picordes moluccemi's, all other species foraged at
low and medium heights in both habitats (>75%). However, woodpeckers in the
plantations tended to feed at lower heights in comparison with the natural forest
sites. Both the gleaners were found feeding at low heights consistently in both the
habitats (Fig 14). Species-pair comparisons showed no statistical differences
between the two species. Picordes mol~rccemrs foraged higher in both habitats and
was different from both the species in the specialist forager category (Table 8). The
pair in the opportunist category foraged at similar heights.
g. Tree Species
All woodpeckers used tree species in similar proportions in both the habitats
(Fig 15,16). Kendall's Co-efficient of concordance (W) was 0.652, P < 0.001 in
natural forest and 0.723, P < 0.001 in plantation. In the natural forest, TermimIia
panicula~a, followed by Grewia tilaefolia were the most frequently used trees while
T e c l o ~ grandis was the least used. In the plantatioh Tectona grandis, followed by
Bombm ceiba were the major trees used for foraging while Grewia filaefolia was
the least used. Acoides moluccensis foraged more on Bombax spp, at both sites.
Except in the case of Picoides moluccensis and
Hemicircs canente (in natural forest sites), all other woodpeckers used tree
species in proportion to their availability (Table 9).
h. Foraging Macro Habitat
A total of 267 bird-centered plots were sampled in all five sites together. To
get an overall idea of the foraging habitats of the eight species of woodpeckers, the
data was pooled from all the sites.
Kruskal Wallis one-way ANOVA tests of the total foraging habitat data
parameters from all the sites (Table 10) showed significant differences for only
three parameters : TRNO, DBHl and DBH3. The non-parametric multiple
comparison tests showed significant differences among species pairs only in the
two DBH variables. Prc~rs xanthopygaeus differed from Chtysocolaptes lucidus,
Plcoides moluccenrr,~ and Pictis chlorolophus in its preference for sites with more
small sized trees (DBH class I ) and from the Dlnoprrtm henghalensrs and Picoides
moluccenrrs in having less number of large trees (DBH 3 class). Celerrs brachyunrs
also differed from Picordes molrtccenrrs in its preference for sites with small sized
trees (DBH class 1). No significant differences could be detected in the TRNO in
any of the species pairs.
Data from plantation was excluded to determine the foraging site choice of
woodpeckers in natural habitat. Further, the natural forest sites differed among
themselves in three variables (DBH 2, Tallest Tree and Average canopy height) and
so these variables were eliminated. Data on the two species (Celeuc brachyurus and
Picus xanthopygaeus) that had sample sizes of less than 20 were discarded. Data
on the remaining six species, foraging in natural forest sites along with the available
habitat data were tested for differences. Results of Kruskal-Wallis test is given in
Table 11. Of the five variables considered only two
Table 9
Tree Species Used (for foraging) Vs. Availability
(:, = Spearman's Rank Correlation Coefficient; p = 0.05)
( Species
PY
MA
HS
Yh'
SB
RU
(Significant Value indicates that the use is related to Availability)
Natural Forest r I P
PY = Picoides moluccensis; MA = P, mahrar~ensis; H S = Hemicircus canente; YN = Picus ch1orolophus; SB = P, xanthopygaeus; RU = Celeus hrachyutus; GB = Dinopium benghulense; MG = Chrysocolap~es lucidus.
Plantation r P
I ! I i . ! ! ! ! ! I
turned out significant : SPNO and BA. Multiple comparison tests showed that
Hemicircus canente differed from Picus chlorolophus and the random habitat in
having more number of tree species in its foraging plots, while in the case of Basal
Area (BA), there were no significant differences among the species-pairs.
i. Seasonal differences in Foraging Behaviour and Microhabitats
Due to sample size constraints, analysis of seasonal differences in foraging
was reshicted to four species. The minimum sample size, for each season was at
least 30 foraging observations (except in case of Chrysocolapres lrrcrdus in the
plantation) for these species. The species also represent the three foraging
behaviour categories as defined in the Foraging BehaGour section, above. Figures
17-30 gives details of these seasonal patterns and Table 12 summarizes results of
the statistical tests. There were no differences in foraging behaviour, substrate
condition and DBH size used in any of the species in natural forest sites while in
plantation, substrate size and condition remained constant in all seasons. Larger
sized substrates were used less frequently in the dry season by Dinopium
benghalense and Chrysocolap!es Irrciciu in the natural forest (Fig. 19). In the
plantations, both the Picordcs species gradually decreased the use of trees of
medium DBH classes and increased their use of trees in the smaller and larger
classes in the dry season (Fig. 22). In both the habitats, all species tended to forage
on taller trees in the d ~ y season, although this was not statistically significant in the
case of Chrysocolapres lucrdrts in the plantation (Fig. 23,24). In the natural forest,
woodpeckers tended to forage less frequently at lower heights as the dry season
progressed with corresponding increase in the use of medium and top height classes
(Fig. 25). Such a clear pattern was not seen in the plantation though generally there
was an increase in the frequency of foraging at the top height class (Fig. 26).
Seasonal variations were seen in the use of tree species at both sites (Fig. 29 and
30); though these were not found to be statistically
. .o
. f a
M
m
WE
W
ET
E
IRL
V O
RV
-
LA
TE
Dn
V
sm-
- --
t 40
.-
2m-
LA
TE
WE
T
EA
SIL
Y D
IW
-
LA
TE
Dr
n
am
- .oI
- sm
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1
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aor
101
M
LA
TE
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T
0-
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V Cav
-
LA
TE
rn
UT
E W
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E
AR
LY
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V
.--
LIT
E O
m
FIG
UR
E 2
1
Sea
son
al p
atte
rns
in t
he use
of
Iree
s in
th
e th
ree
DB
H c
lass
es b
y fo
ur
spec
ies
of woodpeckers
for
fora
gin
g in
the Natural
For
est.
T
he
siz
e c
lass
es are:
Sm
all (
7.6
2 -
22.8
6 c
m.)
; Medium (
22.8
7 -
38
.10
cm.)
and ( 1 3
8.1
1 c
m.)
. The
thre
e se
aso
ns are: L
ate Wet -S
epte
mb
er to
Nov
emb
er;
Ear
ly D
ry -
Dec
emb
er to
Feb
ruar
y a
nd
Lat
e Dry - March t
o M
ay.
-- --
I,,, ..-
I- ..-
cs- -1
..-a
."".0rnrnl ..P
100,* .w
=.
Ud
V1
I1
.m
. .D
I
f I M
1
LA
TE
WE
T
I5M
I.V
D
OI
.- L
AT
E D
RI
1 --
L
AT
E W
ET
E
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V O
R1
-
LA
TE
DR
l
; I
40s
nn
LIT
€
ll
~~
EIR
LV
DR
V
.- L
AT
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IC
I
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n l
or
-
FIG
UR
E 2
7
Sea
son
al p
atte
rns in
th
e use o
f fo
ragin
g techniques
by woodpeckers in
th
eNat
ura
l F
ore
st The three seasons
are:
Late
Wet
- September to
Novem
ber
, Early Dry -
Dec
emb
er to F
ebru
ary and L
ate Dry - March to
May.
Table 12
Seasonal Variation in Foraging Parameters [Chi-Square Tests results - P Value 5 0.051
PY = Picoides moluccensis; MA = P. mahrarrensis; GB = Dinoplum benghaleme;
MG = Chrysocolaptes lucidus.
Natural Forest
P Y
MA
GB
MG
Plantation PY
MA
GB
MG
FOBEH
n.s.
n.s.
n.s.
n.s.
DBH TRIIT SUSIZ FORHT SUCON
n.s.
n.s.
<0.01
<0.001
<0.001
<0.001
<0.001
<0.001
n.s.
<0.05
n.s.
n.s.
<0.001
(0.05
<0.001
n.s.
n.s.
n.s.
n.s.
n.s.
n.s.
n.s.
n.s.
n.s.
<0.001
n.s.
n.s.
<0.03
n.s.
n.s.
n.s.
n . ~ .
<0.001
<0.001
n.s.
n.s.
n.s.
n.s.
n.s.
n.s.
<0.001
(0.04
C0.02
n.s.
significant except in the case of the Picoides mahrattensis in the natural forests
(Table 13).
j. Inter-Sexual Differences
Sexes of Dinopium benghalense and Chrysocolaptes lucidrrs were compared
for differences in foraging parameters, habitat-wise (Appendix 8 - 13). There were
no differences in either species in both habitats in any of the parameters except
substrate condition in Chtysocolaptes l~rcidus in natural forest sites, where the
females used relatively more dead substrate than males.
Tree species used by sexes of both species in the two habitats were similar
(Appendix 14). Results of the Spearman's rank cor~elation tests to see if there was
any association between the tree species used by the males and females turned out
significant at the P level of < 0.05 indicating an association.
k. Miscellaneous Observations
The associations of foraging woodpeckers with mixed foraging flocks and
family parties is summarized, season-wise, in Fig.31.32. The association with
mixed foraging flocks reduced considerably during the late dry season for all
species. There was no such clear pattern in case of associations with family parties.
Agg~essive interactions between woodpeckers (inter- and intra-) were not common
(Table 14). Only 29 instances of such interactions were recorded during the 18
months of observations, dominated by three species namely Picordes mahratrenris,
Dinopium benghalense and Chrysocolaptes lucidus.
Nesting Ecology
A total of 63 nests of all eight species together were located during the study
period. This includes 20 'old' nests (18 Ch~socolaptes lucidus and 2
Table 13
Seasonal Variation in the usage of Tree Species by Foraging Woodpeckers
(Significant p Value indicates that there are no seasonal differences in the use of trees for foraging)
(Kendall's Coefficient of Concordance (w); p = 0.05)
PY = P~coides moltrccenris; MA = P, mahrarrensrs; GB = Dinopr~rm benghalenre; MG = Chrysocolaptes lucidus.
I species
PY
MA
GB
MG
Natural Forest W
0.86
0.61
0.93
0.78
' Plantation P
< 0.01
11,s.
< 0.005
< 0.05
W
0.86
0.91
0.80
0.87
P
< 0.01
< 0.005
< 0.05
< 0.01
-h(e
yy
01 q
3~
em
- a
lq
pue lc
lelu
qad
01 J
aq
lua
jaa
- ha
L1n
q
:laq
maA
oN
01 ~a
qm
ald
as
- jafi
al
q :a
m su
oseas a
aq
aq
L -su
oseas a
wl
aq)
UI s
atm
d
Kp
um
j VIM
uo!le!3o
sse u!
pu
n03 s
lam
sla
~3
ad
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om
~o
sa!3ads u
aila
s a
yl q
a~
qm
6
3u
an
ba
~j ar\!)e
lal a
ql
Table 14
Frequency of Aggressive Interactions among
Foraging Woodpeckers over 18 months
PY = Picoides moluccensis; M A = P, mahrattensis; H S = Hemrcrrclis canenre; YN
= Picus chlorolophus; RU = Celerrs brachyrnrs; GB = D~noprrtm benghaleme; MG
= Chrysocolapres lucidus.
- Subordinate +
Dominant 3.
PY
MA
HS
YN
SB
RU
GB
MG
PY
I
M A
.
G B
-
I - -
HS
.
- - . - -
MG
.
2
RU
-
YN
* - . - . . - .
4 3 2 - . - - .
. . I . . . - . .
- - . . - . - - - 2 . 2 3 3 1 -
. - . . . - . a
SB
.
Celeus brachyurus), a nest of Celeus brachyums that was used in both the
years and another of the same species that was located on the same tree but in a
different Cremarogaster ant nest. Hemicircus canente and Picus chlorolophus are
represented by the least number of nests (2 and 3 respectively) while for the others,
the number ranged from 6 to 19. Of the 63 nests, 16 were located in the plantations
and the rest in natural forest habitat.
a. Nesting Phenology
December to hlay appears to be the principal nesting season for woodpecker
species at the Peechi-Vazhani sanctuary (Fig. 33) as most of the nests were found
in this period. Ch~.~ocoluptes Itiodi~s alone appears to be having an extended
nesting season during the South-west monsoon period. However, only one active
nest was seen during the study (July-Sept) and the phenology for this species was
based on this nest and sightings of juveniles with dark iris colouration, which
followed and were fed by adult birds. These juveniles were sighted from September
to November and February to April in different localities. Presumably, the birds
also breed in December - January. On one occasion, a pair of Hemicircus canenre
was seen moving around with a juvenile, which they fed, in late December. On
another instance a pair of Plcordl- niahrarrensrs was seen feeding chicks at nest in
late December. It is therefore possible that some individuals may nest earl~er than
the peak breeding season.
b. Nest Characteristics [Table 151
Four species of u oodpeckers (Dinopium benghalense, Celetcs brachyunrs,
Plcoides mahrarrensis and Pictts chlorolopus) nested both on bunk and branches
while Chrysocolaptes lucidtis nested exclusively on the trunk. The remaining three
species nested exclusively on the branches. Pooling all the nests (except Celeus
brachyutus nests), 24 o f the 56 nests (42.9%) were excavated on branches and 32
(57.1%) on trunks.
PI' Y.Ol:T S.h'ST INCII. EXCV.
I ; R y . r t 'r .:*r:r*..:+I. I'.' ' v:.l:.r..:*****x*I'***s:xatII:
I N C I ' . ~ r + * : k * a * * i * * r x * r ESCY. r a . r ~ ~ j : * * ~ t * ~ * * * r
Ncs1111g phenology of woodpeckers. EXC\' E\cavat~ng of I ~ c ~ I - c ~ ~ I I ) , lNCn = lncubat~llg of e a s ;
Y SST - Young al nest. Y .OUT = Young outside nest
The spccles codes are. PY =f' lcu/d~s n~olrrcccm~s; MA = P. mahrarremrJ; HS = Hi,m/orc~~.r co~rrn~c, YN = Ants clrl ~lr~plirrs; SB = I'/ctr.r xanrhop~jiocus
KU = ('cleus ~V~CIIYI~RI~; GB I )~nop~um he11~11aknrc; MG = Chrysorolop~e.~ hcidrcs.
The nesting substrates were live in 30 nests (53.6%) and dead in case of 26
(46.4%) nests. Further, six (20%) of the nests on live substrates had broken tops or
fungal conks near the nest holes, while 22 nests (85%) on dead substrates were
characterized by presence of fungal conks broken tops and lack of bark on nest
branch (Table 16). Picorcies moluccensis, Hemicircus canenre and I'rcus
chlorolophus nested exclusively on branches which were also weak (indicated by
the presence of fungal conks, broken tops and lack of bark). Nests of
Ch ysocolopres lucidus were all excavated on live boles of trees.
Nest heights ranged from 2.13 m to 15.24 m (Fig.34). Picus xanthopygaeus
had the lowest mean height (5.8m) while Prcordes moluccensis had the largest (10.0
m). Nest heights, when compared using Kruskal Wallis one-way ANOVA showed
significance at p < 0.02. The multiple comparison test did not indicate any
difference for species pairs. Nest heights were not correlated to body size
(Spearman Rho [ r ] = -0.32). Diameter at nest height ranged from 7.62 cm to 50.8
cm. (Fig.35). Plcordes n~ol~rccensls had the lowest mean value (12.6 cm) while
Chrysocolaptes lrtcrd~rs had the largest (39.3 cm). DNH was positively correlated to
the body weight : r = 0.96 (Spearman's Rho; P < 0.01). DNH for Chrysocoloptes
lucrdrrs were significantly larger than those for the Hemicirctrs canenre and the two
species of P i ~ o , ~ l e s . DNH for Plcordes mc~lrrccensis was significantly smaller than
for Dlnopium bcngholenre.
Overall there were only two (3.2%) nests opening upwards. Half of the
remaining nests - 30 (48.4%) - were vertical and these nests opened horizontally
and the same number of nest enhances opened downwards.
The nest-hole orientation appears to be random (Fig.36), though fewer holes
an oriented between tile azimuth 316 degree to 90 degree. There was
Table 16
Condition of Nesting Substrates of Woodpeckers
Species (n)* L ive Live with 1 I Dead with
PY = Prcordcs molrrccenris; MA = P, mahrattenrrs; H S = Hemrcrrclrs canente; YN
- I'/cus chlorolophus; RU = ('eleus braclyrrnrs, GB = Drnoprum benghalense; MG
= Chrysocolaptcs lucrdus.
Broken top1 Fungal Bract
1 n = Number o f nests.
Dead Broken topMo barklFungus
NE
ST
HE
IGH
T (
m.)
-
-
--
-
---
-.
-- I
0
I 1
I I
I 1
I I
PY
M
A
HS
Y
N
SB
R
U
GB
M
G
WO
OD
PE
CK
ER
S
PE
CIE
S
FIG
UR
E 3
4
-
Hei
ghts
at
wh
ich
woo
dp
eck
er n
ests
wer
e lo
cate
d. T
he
figu
re s
how
s th
e m
axim
um
, min
imw
n and m
ean
values.
m
vl
The s
pec
ies c
od
es are:
PY
= P
icoid
es m
olu
ccen
sis;
MA
= P
. m
ah
m~
tem
is; HS =
Hem
icir
rus
can
enre
; YN =
Pic
rcr
chlo
rolo
ph
us;
SB
= P
icu
s xan
&opyg
aeu
s ; R
U =
Cel
eur bru
chyu
rus;
G
B =
Din
opiu
m b
engh
ule
nse
; MG
= C
h~
soco
lap
,res lu
cidu
s.
considerable variation among individual species. For the Chrysocolaptes lucidus
alone, which had larger sample sizes the results showed that nearly half (47.37%)
ofthe nests were facing South-West (Fig.37).
Nest hole diameters (the larger one in case of oval-shaped nests) ranged
from 3.18 cm to 15.24 cm. (Fig.38). These were positively correlated with
woodpecker body weight (Spearman's Rho [r ] = 0.86; P < 0.01). DNH and nest
hole diameter sizes were also positively correlated (Spearman's Rho [r] = 0.86; P <
0.05). Nest holes of Chrysocolaptes l~rcidrrs were significantly larger (p < 0.001)
than those of the two I'icoides species (Non-parametric Multiple Comparison Test).
The shape of the nest hole entrances was not consistent in majority of the
species, except in Picoldes mol~tccensrs, Chrysocolaptes lucrdrrs and Hemicirctrs
conenre, which was circular in the first species and oval in the latter two species.
Overall, there was not much difference in the frequency of either (Round = 48.4%
vs Oval = 5 1.6%).
c. Nest tree Characteristics (Table 17)
The sixty two nests were located on 17 species of trees (Fig 39). Among
these, li.rmrnalra pnicrrlara was the most frequtj~tly used having ten nests of five
woodpecker species, This was followed by Terramelcs nudjlora - 9 nests (all
Chrysocolapres lucidus), Tecrona grandis (a), Bombax spp. (7), and Grewra
tilaejolia (7). Fourteen of the nineteen nests (73.7%) of Chrysocolapres lucidus
were located on the two tree species : Telrameles nudiflora and Bornbar insigne.
Nest tree heights ranged from 4.8m to 28.96 m (Fig.40). Kruskal-Wallis test
results to see if there were differences in choice of t m s among the woodpecker
FIGURE 37
Onentatlon of Chrysocolopres lucrdtrs nest camnes Each polnt represents a nest
TR
EE
HE
IGH
T(M
1
- -
0
--
I
1
I I
PY
MA
H
S
YN
SB
R
U
GB
M
G
WO
OD
PE
CK
ER
SP
EC
IES
F
IGU
RE
40
Hei
gh
ts of tr
ees
sele
cted
for n
esti
ng b
y w
ood
pec
ker
s.
Th
e m
axim
um
, min
imu
m a
nd
mea
n v
alu
es a
re g
iven
.
The s
pec
ies
cod
es am: PY =
Pic
oid
es m
olu
ccem
t; M
A =
P.
mah
mft
emis
; HS
= H
em
icim
-m
e;
YN =
Pic
us
chlo
rolo
pIln
rs; S
B =
PIC
US
xa
nth
opyg
aeeu
r ; RU
=
Cel
eus
bm
chyu
-;
GB
= D
inopiu
m b
engh
ale
nse
; MG
= C
hry
soco
lapte
s lu
cidu
s.
species were highly significant (P < 0.001). Chrysocolaptes llrcidus nested on taller
trees than Picus xanrhopygaeus and Picoides mohrarrensis. The relation of nest
height versus tree height differed from species to species. Picoides moluccensis
showed very high correlation (Spearman Rho, r = 1.0), Dinopium benghalense
showed moderate positive correlation (0.68), while Prcus xanrhopygae~rs, Picoides
mahratlensis and Chrysocolapres lucidrts no correlation (0.18; 0.125 and -0.02
respectively).
There was considerable variation in the range of DBH of nest trees used by
each woodpecker species (Fig.41). Nest trees of Chrysocolapres lircrdus were
significantly larger than those used by Prcordes mahrattensis and Picus
xatrthopygaeus (Non-parametric Multiple Comparison Test; P < 0.05). Nest tree
condition was consistent : only one of the 62 nest trees (1.6%) was dead. All the
others were on live trees. Most nests were located > lOOm from water and few
were located away from clearings (Table 17). There was a tendency for
disproportionate use of trees with larger DBH and height though these were
available in smaller proportion (Fig.42, 43).
d. Nest Site Characteristics (Table 18)
Nest s i ~ ~ s of Ch~socolapte.~ 1ucrd11.s differed significantly from the nest
sites of Prcus xanthopygoeus, being located in more mature forests having more
trees in larger height and DBH classes, with more basal area and greater average
canopy heights. Prcordes mahrarrensrs nests were located in areas with shorter
stahlre t m s and differed significantly from those of Chrysocolaptes lucidus in both
the parameters invloving tree heights. Nest-sites of Picoides moluccensis also
differed from those of Chrysocolapres Iltcid~cs in having significantly lower average
canopy height values. Other species exhibited no significant differences in their
nest-site characteristics. There was, as noted in the earlier sections, considel.ablr
variation within the species in most of the variables.
! I
80 i I
M
40
-
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LL
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ED
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IAL
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11-1
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PLA
NTA
TIO
N
FIG
UR
E 53
Kel
at~v
e freq
uenc
y O
~O
~C
II
II
~I
IC
~
and
use
of r
rces
Ibr
rle$
tlllg
by w
oodl
~cch
ers 11
1 rl
~e
tl~r
ee tree
I~
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t cl
asse
s In
the
two
hab~
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Dat
a fr
om a
ll sp
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e po
oled
The
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ght c
lass
es a
re-
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all (
5 9
m );
Med
ium
( 9.
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5 m )
and
Tal
l ( 2
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.).
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