Breeding Biology of the Yellow-legged Gull (Larus michahellis, Naumann, 1840): a Small Island Population in Southwestern Türkiye

Abstract

Urbanization and fisheries affected a rapid increase in seagull populations in western Mediterranean populations of the yellow-legged gull. The main reason is the increased food resources such as fisheries, big ports, and dumps. In this study, we aimed to understand and to compare the breeding biology of the yellow-legged gull in eastern Mediterranean. We studied on the small island in southwestern Türkiye between 2013 and 2015. All nesting sites were determined, marked, and monitored once a week. The breeding season has started in late February, nesting and laying eggs have started at the beginning of March, and they left the island in the second half of June after fledging. The incubation period is 29.17±2.85 days, only one clutch in a season and 2 or 3 eggs were laid in the nests. There was a slight increase in the number of pairs and nests between years but there is no significant difference in all parameters such as laying date, clutch size, hatching and fledging success in Pırasalı Island population and the rate of both hatching and fledging success are lower than western Mediterranean populations. While predation is the weakest factor for lower breeding success, intraspecific predation may be the factor but the main effect is the lower food abundance for the hatchlings.