Home – Home – Jornals – Contemporary Problems of Ecology 2025 number 2

Our study is devoted to foraging strategies of sympatrically nesting Glaucous Gulls (Larus hyperboreus) and Vega Gulls (Larus vegae) in two locations on the Chaunskaya Bay of the East Siberian Sea. Both species of gulls nested both in colonies and single pairs, and their foraging methods were similar: scavenging, collecting, and active predation on eggs and chicks. Anthropogenic food sources were prioritized by both species. The second most important food source for Glaucous Gulls was birds, whereas for Vega Gulls it was isopods. Differences in diet between gulls breeding in colonies vs gulls breeding as single pairs were more substantial than differences in food spectrum between different species with the same nesting strategy. This pattern is especially prominent in with Vega Gulls. Single pairs of both species could not afford long foraging trips and foraged in the cloth vicinity of their nests, using other bird species as a prey (a stable available resource in the nesting habitat). Colonial gulls foraged mostly on landfills (a stable resource but located far away from the nesting sites).