Parental behaviour and family proximity as key to gosling survival in Greylag Geese (Anseranser)

摘要

Reproductive success in monogamous species is generally affected by both behavioural and hormonal fine-tuning between pair partners. Vigilance, defence and brooding of offspring are among the main parental investments, and often the sexes adopt différent roles. In the présent study, we investigate how sex différences in parental behaviour and family proximity in the socially monogamous Greylag Goose (Anser anser) affect gosling survival. Düring the reproductive season in spring 2013, we recordedthe behaviour of 18 pairs with offspring and gosling survival in a semi-tame, long-term monitored, and individually marked flock of Greylag Geese in Grünau, Austria. We found that behavioural role differentiation between the parents varied with developmental phase, and thus with gosling age. Especially during the first 10 days after hatching, females were foraging more frequently than maies, which were more vigilant and aggressive towards other flock members. Such différences between the sexes levelled out 20 to 30 days after hatching. In gênerai, females stayed in closer proximity to their offspring than maies. Gosling survival was high when the parents were relatively aggressive and emphasized vigilance rather than foraging behaviour. Hence, we show a direct link between pair partners' quality of parental investment and gosling survival.