The food and feeding ecology of Adélie penguins (Pygoscelis adeliae) and Chinstrap penguins (P. antarctica) at Signy Island, South Orkney Islands

摘要: Adelie Pygoscelis adeliae and Chinstrap P. antarctica penguins are important consumers of Southern Ocean marine resources. The stomach contents adult at Signy Island, South Orkney Islands, were analysed quantitatively throughout the chick-rearing period. They consisted almost exclusively Antarctic krill Euphausia superba, Adelies eating 35–63% by number 23–28% weight juvenile Chinstraps 72–87% 90–95% mature krill, as well small amounts offish amphipods. Interspecific dietary differences may partly be attributable to starting breeding one month before but, they persist when both simultaneously rearing chicks, two species also forage in somewhat different areas. Krill data from net hauls indicate a substantial overlap size taken scientific, probably commercial, operations penguins. Chicks fed c. 300 g food 0–5-0-8 times per day, chicks without sibling being most frequently. Chicks often late afternoon, estimates swimming speed feeding frequency adults feed quite extensively night.