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Foraging behaviour of the Near Threatened Grey-Headed Bulbul Pycnonotus priocephalus in Relation to Seasons and Breeding Stages


  • Wildlife Research and Conservation Trust, C/o Anupallavi, Chungathara P.O., Nilambur 679 334, Kerala, India


I studied the foraging behaviour and adaptive strategies of the Grey-headed Bulbul Pycnonotus priocephalus, an endemic species of the Western Ghats, India, in relation to seasons and reproductive stages in two tropical rainforest sites, Silent Valley National Park and Muthikkulam Reserve Forest, from 2002 to 2005 and 2012 to 2013. The species was recorded to use various foraging manoeuvres and food handling techniques, and was found to frequently use energy conserving manoeuvres and feeding techniques such as gleaning and gulping. There were significant differences in its foraging height and foraging tree use due to differential habitat selection during the breeding and non-breeding seasons. It showed plasticity in the foraging behaviour during the different reproductive stages. Its participation in mixed-hunting flocks during the local migratory phase (non-breeding season) seems to be an adaptive strategy to cope with resource competition and predation risks in a new and challenging habitat, which is in accordance with other studies on the flocking behaviour of tropical birds.


Behavioural Plasticity, Foraging Behaviour, Grey-Headed Bulbul, Mixed-Species Flocks, Pycnonotus Priocephalus, Western Ghats.

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  • Ali, S. & S.D. Ripley (1987): Handbook of the Birds of India and Pakistan. Compact edn. Oxford University Press, New Delhi.
  • Ali, S. (1932): Flower-birds and bird-flowers in India. J. Bombay Nat. Hist. Soc. 35(3): 573–605.
  • Balakrishnan, P. (2007): Status, distribution and ecology of the Greyheaded Bulbul Pycnonotus priocephalus in the Western Ghats, India. Ph.D. thesis, Bharathiar University, Coimbatore.
  • Balakrishnan, P. (2011): Breeding biology of the Grey-headed Bulbul Pycnonotus priocephalus (Aves: Pycnonotidae) in the Western Ghats. India. Journal of Threatened Taxa 3: 1415–1424.
  • Basha, S.C. (1999): Forest types of Silent Valley. Pp. 109–116. In: Manoharan, T.M., S.D. Biju, T.S. Nayar & P.S. Easa (Eds): Silent Valley Whispers of Reason. Kerala Forest Department, Thiruvananthapuram.
  • Bhatt, D. & A. Kumar (2001): Foraging ecology of Red-vented Bulbul Pycnonotus cafer in Haridwar, India. Forktail 17: 109–110.
  • BirdLife International (2014): Species factsheet: Pycnonotus priocephalus. Downloaded from < on 30/10/2014.>
  • Brennan, L.A. & M.A. Morrison (1990): Influence of sample size on interpretations of foraging patterns by Chestnut-backed Chickadees. Studies in Avian Biology 13: 187–192.
  • Chen, C. & F. Hsieh (2002): Composition and foraging behaviour of mixed-species flocks led by the Grey-cheeked Fulvetta in Fushan Experimental Forest, Taiwan. Ibis 144: 317–330.
  • Collar, N.J., M.J. Crosby & A.J. Stattersfield (1994): Birds to watch 2. The world list of threatened birds. BirdLife International, Cambridge.
  • Dobb s, R.T. & T.E. Martin (1998): Variation in foraging behavior among nesting stages of female red-faced warblers. Condor 100: 741–745.
  • Fishpool, L.D.C. & J.A. Tobias (2005): Family Pycnonotidae (Bulbuls). Pp. 124–253. In: del Hoyo, J., A. Eliott & D.A. Christie (Eds): Handbook of the Birds of the World. Vol. 10. Lynx Edicions, Barcelona.
  • Fontaine, J.J. & T.E. Martin (2006): Parent birds assess nest predation risk and adjust their reproductive strategies. Ecology Letters 9: 428–434.
  • Goodale, E., B.Z. Nizam, V.V. Robin, H. Sridhar, P. Trivedi, S.W. Kotagama, U.K.G.K. Padmalal, R. Perera, P. Pramod & L. Vijayan (2009): Regional variation in the composition and structure of mixed-species bird flocks in the Western Ghats and Sri Lanka. Current Science 97: 648–663.
  • Hutto, R.L. (1990): Measuring the availability of food resources. Studies in Avian Biology 13: 20–28.
  • Jullien, M. & J.M. Thiollay (1998): Multi-species territoriality and dynamic of neotropical forest understorey bird flocks. Journal of Animal Ecology 67: 227–252.
  • Krebs, J.R. & A. Kacelnik (1991): Decision making. Pp. 105–136. In: Krebs, J.R. & N.B. Davies (Eds): Behavioural Ecology: An Evolutionary Approach. Blackwell Scientific, Oxford.
  • Lack, D. (1971): Ecological isolation in birds. Blackwell Scientific Publications, Oxford and Edinburgh.
  • Levins, R. (1968): Evolution in Changing Environments. Princeton University Press, Princeton.
  • Lovette, I.J. & R.T. Holmes (1995): Foraging behavior of American Redstarts in breeding and wintering habitats: implications for relative food availability. Condor 97: 782–791.
  • Martin, T.E. (1987): Food as a limit on breeding birds: a life-history perspective. Annual Review of Ecology and Systematics 18: 453–487.
  • Martin, T.E. & J.R. Karr (1990): Behavioral plasticity of foraging manoeuvres of migratory warblers: multiple selection periods for niches? Studies in Avian Biology 13: 353–359.
  • Martin, T.E, J. Scott & C. Menge (2000): Nest predation increases with parental activity: separating nest site and parental activity effects. Proceedings of the Royal Society of London Series B, Biological Sciences 267: 2287–2294.
  • Milinski, M. & G.A. Parker (1991): Competition for resources. Pp. 137–168. In: Krebs, J.R. & N.B. Davies (Eds): Behavioural Ecology. An Evolutionary Approach. Blackwell Scientific, Oxford.
  • Moermond, T.C. (1990): A functional approach to foraging: morphology, behaviour, and the capacity to exploit. Studies in Avian Biology c13: 427–430.
  • Morrison, M.L., C.J. Ralph, J. Verner & J.R. Jehl Jr. (Eds) (1990): Avian foraging: theory, methodology, and applications. Studies in Avian Biology No. 13. Cooper Ornithological Society, California.
  • Munn, C.A. (1986): Birds that 'cry wolf'. Nature 319: 143–145.
  • Nair, P.V. & K. Balasubramanyan (1985): Long-term environmental and ecological impact of multipurpose river valley projects. KFRI Research Report 26. Kerala Forest Research Institute, Peechi.
  • Pianka, E.R. (1973): The structure of lizard communities. Annual Review of Ecology and Systematics 4: 53–74.
  • Remsen Jr., J.V. & S.K. Robinson (1990): A classification scheme for foraging behaviour of birds in terrestrial habitats. Studies in Avian Biology 13: 144–160.
  • Root, R.B. (1967): The niche-exploitation pattern of the Blue-gray Gnatcatcher. Ecological Monographs 37: 317–350.
  • Sakai, H.F. & B.R. Noon (1990): Variation in the foraging behaviours of two flycatchers: associations with the stage of the breeding cycle. Studies in Avian Biology 13: 237–244.
  • Sridhar, H., G. Beauchamp & K. Shanker (2009): Why do birds participate in mixed-species foraging flocks? A large-scale synthesis. Animal Behaviour 78: 337–347.
  • Stotz, D.F. (1993): Geographic variation in species composition of mixed species flocks in lowland humid forests in Brazil. Papéis Avulsos Zoologia 38: 61–75.
  • Sullivan, K.A. (1984): Information exploitation by downy woodpeckers in mixed-species flocks. Behaviour 91: 294–311.
  • Vijayan, V.S. (1975): Ecological isolation of Bulbuls with special reference to Pycnonotus cafer cafer and P. luteolus luteolus at Point Calimere, Tamil Nadu. Ph.D. thesis, University of Bombay, Bombay.
  • Zar, J.H. (1999): Biostatistical Analysis. 4th edn. Prentice-Hall, New Jersey.