Food preference of the Black-headed Gull Chroicocephalus ridibundus differs along a rural–urban gradient

Abstract

Capsule Black-headed Gulls along a rural–urban gradient chose a food type most associated with their immediate environment, and showed differences in their response to provisioned food, with more urban birds quicker to respond.Aims To determine whether Black-headed Gulls prefer natural versus anthropogenic food along a rural–urban gradient and so determine whether they select prey primarily according to familiarity.Methods Gulls were allowed to choose between provided anthropogenic and natural foods in 11 locations along a rural–urban gradient. Twenty tests were carried out in each location and the preference and time taken for the birds to select food recorded.Results Black-headed Gulls preferred food types most likely to be found in their immediate environment. Birds in more urban environments were quicker to respond to artificially provisioned food. Across environments, Black-headed Gulls showed the capacity to learn by decreasing the time taken to respond to artificially provisioned food, both within and between sessions.Conclusion While there were differences in preference, it is unlikely that Black-headed Gulls were moving freely between rural and urban habitats to satisfy specific nutritional demands. Instead we conclude that juveniles adapt their foraging behaviour to their wintering habitat, which they are likely to select largely stochastically.