CLUTCH ABANDONMENT - A STATE-DEPENDENT DECISION IN KING PENGUINS

When King Penguin Aptenodytes patagonicus males arrive on the breeding grounds to start courtship, their energy reserves must sustain them d uring a fast lasting about five weeks, including the first incubation shift. If the female is delayed in relieving the incubating male, he m ust make a state-dependent decision of how long to wait until abandoni ng the egg (i.e. breeding failure). This is ultimately a life-history trade-off between current reproduction and future survival, and includ es consideration of the size of his remaining energy reserves and his ability to replenish exhausted body reserves (foraging skills). Experi enced males that abandoned the egg weighed significantly less (9.49 kg ) at departure than relieved males (10.43 kg), but inexperienced males abandoned the egg at a nearly significantly higher body mass (10.27 k g) than experienced males. I conclude that experienced birds can compe nsate for lower body reserves by being more proficient foragers.