Fish in the diet of the Antarctic shag Phalacrocorax bransfieldensis at Laurie Island, South Orkney Islands

Abstract

The analysis of 29 stomach contents collected from a colony close to Pirie Peninsula, South Orkney Islands, from 2 January to 18 February 1995, showed that fish were by far the most important prey of the Antarctic shag Phalacrocorax bransfieldensis, followed by octopods, decapods and gammarids. The fish Notothenia coriiceps constituted the bulk of the diet; however, its importance decreased by the end of the study when Lepidonotothen nudifrons was the most important prey. The composition of the stomach contents varied throughout the breeding season according to changes in the chicks' energetic demands; as chicks grew older the adults increased the mass of the loads carried to the nests, preying on larger fish, a phenomenon also observed at the South Shetland Islands.