King penguin Aptenodytes patagonicus diving and breeding behavior in years with contrasting prey availability at South Georgia : State-dependent allocation of time, body mass and diving effort: Sub-optimal life-history decisions in King penguins

Abstract

During three subsequent reproductive seasons with contrasting food availability, the King Penguin Aptenodytes patagonicus responses were monitored in a small colony at Husvik, South Georgia. Observations of metal flipper rings were complemented with transponder implants; automatically scaling and time-depth recorders. Three central life-history parameters were studied: (1) Body reserves adjustments, (2) allocation of time and (3) off shore foraging (diving) behaviour. During the last season, poor food condition forced the birds to make state-dependent decisions that maximised foraging effort and squeezed time budgets, in order to maintain body mass. However, and contrary to life-history theory, at the cost of future fecundity.