Health status indices of Kelp Gull populations in South Africa

Abstract

ABSTRACT Kelp Gulls Larus dominicanus are widespread globally due to their ability to exploit a wide variety of resources and foraging habitats inland, in coastal areas and offshore. However, the increasing availability of anthropogenic diet items might potentially impact the health of their populations. We investigated body condition and parasite loads of incubating adult Kelp Gulls and their chicks at seven South African breeding colonies with varying proximity to landfills. Adult body condition indices did not differ significantly among colonies during the incubation period but were on average highest at one of the urban colonies, Strandfontein, which is next to a large landfill site in Cape Town. The only blood parasite identified was Haemoproteus spp. Prevalence overall was low, but significantly higher in adults than in chicks. Yeast cells (Candida spp.) were identified in faecal smears and coincided with higher body condition index values in incubating adults. Our results suggest that urban landscapes currently have little impact on these aspects of gull health, at least on individuals in good enough condition to breed.