Kleptoparasitism in gulls Laridae at an urban and a coastal foraging environment: an assessment of ecological predictors

Spencer, Robert ORCID: https://orcid.org/0000-0003-0860-4717, Russell, Yvan I. ORCID: https://orcid.org/0000-0003-4608-4791, Dickins, Benjamin J. A. and Dickins, Thomas E. ORCID: https://orcid.org/0000-0002-5788-0948 (2017) Kleptoparasitism in gulls Laridae at an urban and a coastal foraging environment: an assessment of ecological predictors. Bird Study, 64 (1) . pp. 12-19. ISSN 0006-3657 [Article] (doi:10.1080/00063657.2016.1249821)

Preview

PDF - Final accepted version (with author's formatting) Download (293kB) | Preview

Abstract

Capsule: Kleptoparasitism in gulls occurred at a greater rate at an urban compared with a coastal site. Population density and prey size predicted the rate of kleptoparasitism at the urban site.
Aims: To investigate and assess the ecological variables associated with kleptoparasitism among gulls at urban and rural sites.
Methods: Field observations were conducted at Brancaster (coastal rural) and Billingsgate Market (urban) to examine differences in the rate of kleptoparasitism in mixed-species flocks of gulls. Four key variables (prey size, population density, season and species) were assessed as predictors of kleptoparasitism.
Results: Generalized linear models revealed significant effects on kleptoparasitism rate of site, population density and prey size, and two-way interactions between these main terms. Population density and prey size differed significantly between sites, but population density appeared to predict the rate of kleptoparasitism.
Conclusion: Kleptoparasitism may well aid invasion and increase the range of environments a gull can tolerate by helping them meet their energy needs in novel environments where normal foraging behaviours are difficult to implement.

Actions (login required)

View Item