15 research outputs found
Response of young and adult birds to the same environmental variables and different spatial scales during post breeding period
An invasive gull displaces native waterbirds to breeding habitats more exposed to native predators
A 1-year, placebo-controlled, double-blind house-dust-mite immunotherapy study in asthmatic adults
Kleptoparasitism in gulls Laridae at an urban and a coastal foraging environment: an assessment of ecological predictors
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