Sex‐specific patterns in baseline corticosterone and body condition changes in breeding Red‐footed Boobies Sula sula

摘要: Plasma levels of corticosterone often mirror changes in body condition and parental effort. In seabirds, the brooding young chicks is paralleled by a marked decline adult condition. This may reflect trade-off between needs chick to be fed regularly brooded, that spend enough time at sea restore its reserves find food for chick. this paper, we describe baseline tropical seabird, Red-footed Booby Sula sula , which continuously brooded 5‐6 weeks. Body did not during period. Female remained stable throughout breeding whereas male declined significantly late chick-rearing Baseline were low prelaying phase, increased incubation highest Later period, decreased markedly females, but stayed elevated males. There was no correlation Because chick’s slow growth reduced daily need food, Boobies require increase effort, rise probably more reflection slight foraging activity. males are 15% smaller than females suggest period likely result from higher energetic flight costs or lower efficiency imposed size.