Supersize Me: Does Anthropogenic Food Change the Body Condition of Silver Gulls? A Comparison Between Urbanized and Remote, Non-urbanized Areas

Abstract

Urban populations of several gull species worldwide are increasing dramatically and this is often assumed to be a result of greater access to anthropogenic food obtained in urbanized environments. This research investigated the potential effects of an anthropogenic diet on the mass and body condition of Silver Gulls (Larus novaehollandiae) by comparing birds at a remote, non-urbanized site (Furneaux Island Group) with those at an urbanized (Hobart) site in Tasmania, Australia. The mass, size and body condition of gulls were independent of whether or not a bird was breeding, and independent of the stage in the breeding cycle. Male gulls from this urban environment were heavier and of greater body condition than the structurally identical, non-urban gulls, but no differences were detected between females.