Social factors in population regulation of the Silver Gull, Larus novaehollandiae Stephens

Abstract

Intraspecific hostility in the silver gull, Larus novaehollandiae, occurs at the individual level in relation to all its activities. The degree of dispersion that results varies from close range during resting to various distances in different feeding situations and territorial colonialism during breeding. It is suggested that the factor primarily responsible for limiting colony size is food supply within foraging range, and that feeding rights gained through hostility between individuals, not competition for nesting sites, determine which birds can breed.