Effects of weather and sea-ice on the reproductive performance of the Adélie penguin at Edmonson Point, Ross Sea
The breeding biology of the Adélie penguin (Pygoscelis adeliae) was studied at Edmonson Point, Victoria Land, during the 1999, 2001 and 2003 breeding seasons. Weather and sea-ice regimes varied notably, especially in 2003, which was characterised by extensive and persistent sea-ice and strong winds with snowfalls in December. First incubation trips by females were significantly longer than in 1999 and 2001, which in turn delayed the mean departure date of males on the second incubation trip. A high number of chicks died during the post-hatching stage and the breeding success was low with 0.3 chicks crèched per nest with eggs. The mean crèching date was also delayed compared to dates recorded in 1999 and 2001. The average weight of adults rearing chicks was lower in 2003. It is suggested in this paper that the ability of penguins to cope with severe short-term weather events could be reduced when longer-term events, such as anomalies in the persistence of sea-ice, have affected body condition.