Does access to high-quality pelagic prey increase the breeding success of Kelp Gulls Larus dominicanus in the Antarctic Peninsula?

SILVA MP, M FAVERO, S COPELLO & R BASTIDA

MARINE ORNITHOLOGY

Año: 2001 vol. 28 p. 81 - 84

1018-3337

An analysis of the diet of the Kelp Gull Larus dominicanus during the chick-rearing period at a colony in northern Gerlache Strait, Antarctic Peninsula showed that Antarctic Krill Euphausia superba made up 20% by mass of the diet of the adults and 66% by mass of the chicks’ diet. Fish constituted a low proportion of total prey, both in pellets and chick regurgitations, whereas the importance of limpets in adult pellets was similar to results from other studies in Antarctica. Chick regurgitations show substantial differences in the diet at the study site with other localities. Our data on breeding success were in accordance with localities farther south in Antarctica where Kelp Gull chicks are fed offshore prey. Antarctic Krill may represent a substantial resource for Kelp Gulls in some localities as those reported here; the abundance of this resource during the chick-rearing period, associated with low levels of predation by skuas and with favourable local climatic conditions, could be linked with very high reproductive success in the study area.Larus dominicanus during the chick-rearing period at a colony in northern Gerlache Strait, Antarctic Peninsula showed that Antarctic Krill Euphausia superba made up 20% by mass of the diet of the adults and 66% by mass of the chicks’ diet. Fish constituted a low proportion of total prey, both in pellets and chick regurgitations, whereas the importance of limpets in adult pellets was similar to results from other studies in Antarctica. Chick regurgitations show substantial differences in the diet at the study site with other localities. Our data on breeding success were in accordance with localities farther south in Antarctica where Kelp Gull chicks are fed offshore prey. Antarctic Krill may represent a substantial resource for Kelp Gulls in some localities as those reported here; the abundance of this resource during the chick-rearing period, associated with low levels of predation by skuas and with favourable local climatic conditions, could be linked with very high reproductive success in the study area.