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

I M

1

4-

aor

101

M

LA

TE

WE

T

0-

Em

V Cav

-

LA

TE

rn

UT

E W

ET

E

AR

LY

DR

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

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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

po

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.

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