Prolonged foraging trips and egg desertion in little penguins (Eudyptula minor)

Penguins share incubation duties between the male and female of a pair. The one left on the nest must fast while its partner is foraging at sea. Nest attendance patterns during the incubation period reflect the way time is al located between the conflicting demands of incubation and foraging. We cond ucted daily nest checks for little penguins (Eudyptula minor) at two locali ties in New Zealand (Motuara Island in the Marlborough Sounds and Oamaru, O tago) in the 1998/99 breeding season and found significant variation in nes t attendance between the two areas. Penguins breeding at Motuara Island mad e significantly longer foraging trips and were in poorer body condition tha n those breeding at Oamaru. Foraging trip durations were significantly corr elated with the body condition of birds at both areas: the poorer the condi tion, the longer the foraging trip durations. The increased risk of egg des ertion observed at Motuara Island is probably a consequence of the prolonge d foraging trips that limit the time available for incubation.