Paying attention but not coordinating: Parental care in European starlings (Sturnus vulgaris)

Sexual conflict occurs in biparental species because working together provides shared benefits while incurring individual costs. In birds, coordination of provisioning visits via turn-taking has been proposed as a strategy to mitigate this conflict. However, alternation of visits requires that birds have access to reliable information on their partner's behaviour. I investigated coordination in the European starling, Sturnus vulgaris, where direct access to information is variable and limited. Using observational data and a short-term mate removal experiment, there was evidence that individuals adjusted their behaviour in response to their partner. Both sexes decreased their provisioning in the hour the partner was removed but returned to pre-experimental levels within 24 hours, which is consistent with "matching" of parental effort, rather than a "compensation" response widely reported in other studies. Despite this, there was no evidence of coordination, both alternation and synchrony of visits did not differ from that expected by chance.