EFFECTS OF WEATHER AND SEA-ICE ON THE REPRODUCTIVE PERFORMANCE OF THE ADÉLIE PENGUIN AT EDMONSON POINT, ROSS SEA

Abstract

The breeding biology of the Adelie 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 signifi cantly 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 creched per nest with eggs. The mean creching 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. Resume La biologie reproductrice du manchot Adelie (Pygoscelis adeliae) a ete etudiee a la pointe Edmonson, en Terre Victoria, pendant les saisons de reproduction de 1999, 2001 et 2003. Les conditions meteorologiques et les regimes des glaces de mer variaient considerablement, principalement en 2003 qui se distinguait par des glaces de mer etendues et persistantes, ainsi que des vents forts et des chutes de neige en decembre. Pendant l’incubation, la premiere sortie des femelles etait nettement plus longue qu’en 1999 et en 2001, ce qui causait un retard dans la date moyenne de depart des mâles pour la deuxieme sortie. Un grand nombre de poussins sont morts dans la periode qui suivait l’eclosion et le succes reproductif etait faible, correspondant a 0,3 jeune en creche par nid pourvus d’œufs. La date moyenne d’entree en creche etait, elle aussi, retardee par rapport aux dates enregistrees en 1999 et 2001. Le poids moyen des adultes elevant des jeunes etait moins eleve en 2003. Ce document laisse entendre que la capacite des manchots de supporter les evenements climatiques rudes pourrait etre reduite lorsque des evenements a long terme, tels que la persistance anormale des glaces de mer, ont affecte leur condition.