The impact of avian predator-scavengers on King Penguin Aptenodytes patagonicus chicks at Marion Island

While ashore King Penguins Aptenodytes patagonicus are fed upon by a guild of five predator-scavenger seabirds. During the winter (April-October) male Southern Giant Petrels Macronectes giganteus killed an estimated 6430 (11.2%) of Marion Island's King Penguin chicks, although most birds only scavenged in the colonies. The rate of predation varied, with peaks in April-May and in September. The proportion of successful attacks was 22.7%. There was a strong correlation between colony size and the rate of accumulation of chick corpses. Kelp Gulls Larus dominicanus and Lesser Sheathbills Chionis minor also scavenged penguin corpses but Northern Giant Petrels M. halli and female Southern Giant Petrels rarely entered the colonies. During the summer predation was mainly by Sub-Antarctic Skuas Catharacta lonnbergi which took eggs and small chicks.