Meeting Abstract
Parental care increases the inclusive fitness of parents by increasing offspring survival. However, in species that take part in biparental care, there is sexual conflict due to differential costs of investment, where each parent benefits from their partner putting in more effort. Turn-taking (or coordination) of nest visits during chick provisioning has been suggested as a strategy to mitigate this conflict. In order for coordination to work, each bird must have access to information about its partner’s behaviour, allowing pairs to respond to each other “in real time”. To date, evidence in support of this type of cooperation has come from species that forage close to the nest (within 45 m) and/or synchronize feeding visits, which likely provides direct information for each partner. We aim to fill this literature gap by investigating variation in feeding-visit intervals in the European starling, Sturnus vulgaris, where foraging distance is greater (~800 m) and therefore direct information on the partner’s behaviour is likely less available. Considering feeding-visit interval as a behavioural phenotype, we tested the hypothesis that parents adjust their interval length based on knowledge of their partner’s feeding behaviour (or indirect cues via chicks). Preliminary analysis suggests feeding-visit interval is a plastic trait, and may vary among years, 1st and 2nd broods, and with brood size. Finally we describe an experiment to directly test the coordination hypothesis, removing one bird during chick-rearing and then measuring their partner’s ability to respond to manipulation of this putative ‘information cue’.
