Breeding patterns of King Penguins on the Falkland Islands

Abstract

The breeding biology of the King Penguin (Aptenodytes patagonicus) has been investigated in detail at sites across its circum-subantarctic range, except at its most temperate location, the Falkland Islands. Aspects of the breeding biology of King Penguins, including timing of laying, brooding and fledging and the length of shifts during incubation and brooding, were studied in the Falkland Islands during the 2001–02 breeding season. The first peak in numbers of pre-nuptial moulting individuals occurred during October and eggs were laid from early November to mid-March. Incubation shifts lasted 10–18 days, and shifts undertaken during the 34-day brooding period were 4–9 days in duration. Foraging trips during the early crèching period were 4–16 days in duration. Chicks that hatched before 22 January reached a mean asymptotic body mass of 8.8 kg in April, while later-hatched chicks increased in mass until July but reached a significantly lower body mass of 7.7 kg. Survival of chicks over winter was high (89%), which may be associated with lower rates of avian predation and less severe weather conditions in the Falkland Islands compared with other breeding sites. Chicks began fledging in mid-November. Late breeders who laid in January and February had a high rate of breeding success. Further research is required at this most temperate colony to confirm the early timing of breeding and the high success rates of early and late breeding attempts.