Shalini Rajakaruna, Rajarata University of Sri Lanka. International Forestry and Environment Symposium 2011 Annual Symposium organized by Department of Forestry and Environmental Science, University of Sri Jayewardenepura, Nugegoda, Sri Lanka http://fesympo.sjp.ac.lk/

1. HABITAT Y
THROUGH AN
Foraging Ecology of Red vented Bulbul
INDICATOR
(Pycnonotus cafer), in university premises and near by
SPECIES-
forest patch, in cafer
Pycnonotus
Mihinthale , Sri Lanka.
S.L. Rajakaruna,
S.wickramasinghe
Faculty of Applied
sciences,
S.L. Rajarata
Rajakaruna, S.wickramasinghe
University of Sri
Faculty of Applied sciences, Rajarata University of Sri
Lanka,Mihinthale
Lanka,Mihinthale.

2. Red vented bul bul (Pycnonotus cafer)
Morphology
-Short crest giving the head a
squarish appearance
-Body is dark brown with a scaly
pattern
-The rump is white
-The vent is red
-The black tail is tipped in white

3. Habitats
-Dry scrubs
-Open forests
-Plains and cultivated lands
Food
-Fruits
-Petals of flowers
- Nectar
- insects and occasionally geckos.
-They have also been seen feeding
on the leaves of Medicago sativa..
(Dinesh Bhatt and Anil
Kumar,2001)

4. The research problem.
 The Red vented Bulbul is one of the most common birds.
 Has a wide distribution
 Found in all types of habitats
 Omnivorous bird who represents the foraging behaviors
of many birds.
 But no evidence about the ecological role of this bird in
the dry zone of Sri Lanka.

5. Objectives
 To identify the foraging behavior of Red vented
Bulbul in the study site.
 To determine the recourse use and extent of
partitioning while foraging.
 To analyze the impact of the foraging behavior red
vented Bulbul on the vegetation.

6. Study site
 This study was confined to the faculty premises of
Faculty of Applied Sciences Rajarata University of Sri
Lanka which is at the periphery of the Mihinthale
sanctuary. (LAT 8° 19' 60" N / LON 80° 31' 0" E)
 It is within the dry zone of Sri Lanka
 Annual rainfall is less than 1000mm
 Average temperature 33-35 0c.

7. Study site
Sri Lanka,
North central
province
Faculty of Mihintale forest
Applied
Sciences
Mihintale Divisional
Secretariat
Mihintale
forest
1:18000

8. Methodology
 Observations were taken along transect of 300m in
length and 50m width
 Scan sampling method was used to observe the
foraging behavior
 No counts were made during heavy rains

9. Methodology contd…
 For each foraging attempt, microhabitat details such
as,
-height above the ground
-substrate from which food is taken and
-the plant species used for feeding
were recorded

10. Methodology contd…
 Mainly the frequencies of pecking and swallowing
were observed
 other activities as preening, resting, roosting, and
social behavior also were concerned
 Vegetation analysis was done to identify the plants
preferred by Red vented Bulbul

11. Results and discussion
 Food preference
Bulbuls are dominant or important frugivores and seed dispersers of open
secondary vegetation throughout tropical and subtropical Asia (Lever 1987,
Corlett 1998).

12. Insect association with the fruits consumed by
Red vented Bulbul
Fruiting tree Presence or Absence of
insects
Grewia flavescens NO
Bauhinia racemosa YES
Azadirachta indica YES
Areca triandra NO
Ficus caulocarpa (unripe) YES
Lantana camara NO

13. Special observation
 They prefer the unripe fruit of Ficus caulocarpa
 Refuse the ripe fruit of the same tree
 When fruits were plucked, opened and observed ,fig
wasps were present in the unripe fruit

14. Utilization of plants

15. Azadirachta indica Bauhinia racemosa

16. Utilization of plants

17. Schleichera oleosa Drypetes sepairia

18. Niche occupancy of Red vented Bulbul
 Height classes
 A: 0m
 B: 0-2m
 C: 2.1-4m
 D: 4.1-6m
 E: 6.1-8m
 F: 8.1-10m
 G: 10.1-12m
 H: <12m

19. Niche occupancy of Red vented Bulbul
Height clusters with different behaviours (January) •Two major clusters
HEIGHT CLUTER WITH OTHER BEAHVIORS (JANUARY)
•H,G.F
33.33 •C,D,E
• Occupancy similarity in 2
major clusters 33.33%
55.56
•H,G classes occupancy
S im ila r it y
similarity 100%
•H & G differs from F in
55.56%
77.78
H,G - Resting
F- Resting
100.00
AH BG C
F D
E ED F
C E- Feeding, Preening and
Observations
Resting
D- Feeding , Preening
C- preening

20. •Two major clusters
Height clusters with different behaviours (February) •Occupancy similarity
HEIGHT CLUTER WITH OTHER BEAHVIORS IN FEBRUARY
36.55%
•A,E, F similarity is
36.55
higher
•B,G,H similarity is
higher
57.70 •C,D similarity is
S im ila r it y
higher
78.85
A- Feeding
E- Feeding
F- Feeding
100.00 B-Preening
A A E E F F B B G G H C C D D
Observations G-Feeding
D-Roosting

21. •Similarity 59.64%
Height clusters with different behaviours
Dendrogram
•Occupancy of the H
(March) Single Linkage, Euclidean Distance height class is less similar
to other classes.
59.64
A- Feeding
B-Feeding
73.09 C-Feeding
S im ila r it y
E- Feeding
F-Feeding, Resting
H-Resting
86.55
•Two major clusters
 End of the rainy
100.00 season and the
A B C G D E F H
Observations Beginning of the
breeding season

22. Conclusion
 Niche occupancy
 All the height classes have been used for feeding
except H (<12m)
 Mostly for feeding – E (6.1-8 m)
 Mostly for Resting – H(<12m)
 Mostly for preening- B(0-2m), C(2.1-4m),D(4.1-6)
 The height class preferred the most by Red vented
Bulbul is
E, (6.1-8.m)

23. Conclusion contd…
 Plant preference
 Red vented Bulbuls show a heights preference in
Asadirachta indica for feeding.
 Scleichera oleosa for resting.
 Drypetes sepairia for roosting.
 Food preference
 Consumed most frequently insects (59%),
 Then fruits ( 21.9%)

24. Conclusion contd…
 There is no considerable adverse impact of Red
vented Bulbul foraging behavior on the vegetation in
the study site.
 As the important plants in the study site, for the
survival of birds have been identified, the findings of
this study can be used for the habitat refreshment of
the ecosystem too.

25. Recommendations…
 To increase the duration of the study to increase the
accuracy.
 To compare the niche occupancy of Red vented
Bulbul with the niche occupancy of other species of
Bulbuls.
 To carry out the same study in an undisturbed forest
patch and compare the two sites.

26. Special Thanks to….
 Dr. Asanga Wijethunga
 Mr. Duminda S. B. Dissanayake
 Mr. Aruna Senevirathne
 Mr. Supun Wellappuliarachchi
 Mr. Adrian Gabriel
 Mr. Ravi Muthukrishna
 Mr. Lasith Rajakaruna

27. Thank you!