O’woma O’woma OKORE, Chidinma AMADI


Ten different bird species were peculiar to the Umudike environment and of these eight were regular thus closely observed and identified. The other two species were scarcely available and may be regarded as visiting birds. The eight species identified were either Passerine or Non-Passerine. The northern grey-headed sparrow (Passer griseus) was one of the Passerine species encountered. The amount of time spent by the birds foraging varied significantly with group size. Pecking rate reduced with increased scanning time. Pecking rate of individuals increased with group size and reduced with increasing group size. Birds in fewer groups will gather food and move away quickly than with smaller groups, the movement characterized by small walks or hops. Scanning rate reduced with increasing group size and increased with reduced group size. Group size was the most determinant factor in determining the relationships between vigilance, hopping and feeding rates.


Full Text:



ALE, S. B. and BROWN, J. S. (2007). The contingencies of group size and vigilance. Evolutionary Ecology Research, 9: 1263 – 1276.

ARNAIZ-VILLENA, A., GOMEZ-PRIETO, P. and RUIZ DE VALLE. V. (2009). Phylogeography of Finches and Sparrows. Nova Science Publishers, Hauppauge, New York.

BARTA, Z., LENVAI, A. Z., LIKER, A. and BOKONY, V. (2004). Flock feeding in house sparrows. Proceedings of the Royal Society, 271: 2467 – 2472.

BECK, M. J. and GEORGE, T. L. (2000). Song post and foraging characteristics of breeding varied thrushes in Northern Western California. Condor, 102: 93 – 103.

BEDNEKOFF, P. A. and LIMA, S. L. (2002). Why are scanning patterns so variable? An overlooked question in the study of the anti-predator vigilance. Journal of African Biology, 33: 145 – 149.

BERTRAM, B. C. R. (1980). Vigilance and group size in ostriches. Animal Behavior, 28: 278 – 286.

BURROW, N. and DOMEY, R. (2001). Birds of Western Africa: Helm Identification Guides. Christopher Helm Publishers, London.

CLEMENS, J. L., BOAS, M. A., FRYS, E. A. and MORTZFELDT, S. A. (2001). Effects of predatory threats on songbird foraging behavior. Journal of Ecological Research, 11: 23 – 26.

CUETO, V. R. and LOPEZ DE CASENOVE, J. (2000). Foraging behavior and microhabitat use of birds inhabiting coastal woodlands in east central Argentina. Wilson Bulletin, 114(3): 342 – 345.

ESTEBAN, F. J., MEGAN, D. G., DOLAN, T., TISDALE, V. and GRAHAM, R. M. (2008). Visual fields of two ground foraging birds. Ibis, 150: 779 – 787.

FAYAT, P. (2003). Insect prey population changes in habitats with declining versus stable three-toed wood pecker (Picocoles tridactylus) populations. Ornithology, 80: 182 – 192.

GABBE, A. P., ROBINSON, S. K. and BRAWN, J. D. (2002). Tree species preferences of foraging insectivorous birds. Biology, 16: 462 – 470.

GIRALDEAU, L. A. and CARACO, T. (2000). Social Foraging Theory. Princeton University Press, Princeton, New Jersey, USA.

KRAUSE, J. and RUXTON, G. D. (2002). Living in Groups. Oxford University Press, Oxford.

JOHNSON, C. A., GIRALDEAU, L. A. and GRANT, J. W. A. (2001). The effect of handling time on interference among house sparrows foraging at different seed densities. Behavior, 138: 597 – 614.

LIKER, A. and BARTA, Z. (2002). The effect of dominance on social foraging tactic use in house sparrow. Behavior, 139: 1061 – 1076.

SCHULENBERG, T. S. (2010). Pin-tailed Whydah (Vidua macroura) Neotropical Birds. Cornell Laboratory of Ornithology, Ithaca.

STRONG, A. M. and SHERRY, T. W. (2000). Habitat-specific effects of food abundance on the condition of ovenbirds wintering in Jamaica. Journal of Ecology, 69: 885 – 895.

WHELAN, J. C. (2001). Foliage structure influences the foraging of insectivorous forest birds; an experimental analysis. Ecology, 82: 219 – 231.

WIKIPEDIA (2013). Northern Grey-headed Sparrow. grey-headed sparrow. Accessed October 12, 2014.


  • There are currently no refbacks.

A Publication of Department of Zoology and Environmental Biology, University of Nigeria, Nsukka, Enugu State, Nigeria.