HABITAT Y THROUGH AN INDICATOR SPECIES- Pycnonotus caferS.L. Rajakaruna, S.wickramasingheFaculty of Applied sciences, Rajarata University of Sri Lanka,Mihinthale

Foraging Ecology of Red vented Bulbul (Pycnonotus cafer), in university premises and near by

forest patch, in Mihinthale , Sri Lanka.

S.L. Rajakaruna, S.wickramasingheFaculty of Applied sciences, Rajarata University of Sri

Lanka,Mihinthale.

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

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)

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.

ObjectivesTo 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.

Study siteThis 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.

Faculty of Applied Sciences

Mihintale forest

Sri Lanka, North central province

Study site

1:18000

Mihintale forest

Mihintale Divisional Secretariat

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

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

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

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).

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

Special observationThey prefer the unripe fruit of Ficus

caulocarpa Refuse the ripe fruit of the same treeWhen fruits were plucked, opened and

observed ,fig wasps were present in the unripe fruit

Utilization of plants

Azadirachta indica Bauhinia racemosa

Utilization of plants

Schleichera oleosa Drypetes sepairia

Niche occupancy of Red vented BulbulHeight classes

A: 0mB: 0-2mC: 2.1-4mD: 4.1-6mE: 6.1-8mF: 8.1-10mG: 10.1-12mH: <12m

Niche occupancy of Red vented Bulbul

FEDCBA

33.33

55.56

77.78

100.00

Observations

Sim

ilari

ty

HEIGHT CLUTER WITH OTHER BEAHVIORS (JANUARY)Height clusters with different behaviours (January)

H G F E D C

•Two major clusters•H,G.F•C,D,E• Occupancy similarity in 2 major clusters 33.33%•H,G classes occupancy similarity 100%•H & G differs from F in 55.56%

H,G - RestingF- RestingE- Feeding, Preening and RestingD- Feeding , PreeningC- preening

DDCCHGGBBFFEEAA

36.55

57.70

78.85

100.00

Observations

Sim

ilari

ty

HEIGHT CLUTER WITH OTHER BEAHVIORS IN FEBRUARYHeight clusters with different behaviours (February)

•Two major clusters •Occupancy similarity 36.55%•A,E, F similarity is higher •B,G,H similarity is higher•C,D similarity is higher

A- FeedingE- FeedingF- FeedingB-Preening G-FeedingD-Roosting

HFEDGCBA

59.64

73.09

86.55

100.00

Observations

Sim

ilari

ty

DendrogramSingle Linkage, Euclidean Distance

Height clusters with different behaviours (March)

•Similarity 59.64%•Occupancy of the H height class is less similar to other classes.

A- FeedingB-FeedingC-FeedingE- FeedingF-Feeding, RestingH-Resting•Two major clusters

End of the rainy season and the Beginning of the breeding season

ConclusionNiche 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)

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 preferenceConsumed most frequently insects (59%),Then fruits ( 21.9%)

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.

Conclusion contd…

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.

Special Thanks to….Dr. Asanga WijethungaMr. Duminda S. B. DissanayakeMr. Aruna Senevirathne Mr. Supun WellappuliarachchiMr. Adrian Gabriel Mr. Ravi Muthukrishna Mr. Lasith Rajakaruna

Thank you!