Pair coordination is related to later brood desertion in a provisioning songbird

Raising a family is not free of conflict for parents, as each parent benefits when its partner provides more care for the offspring. Resolving this conflict requires cooperation between the parents. One way to achieve such cooperation might be to coordinate parental provisioning by synchronizing (i.e. returning to the nest at the same time) or alternating (i.e. taking turns) offspring provisioning at the nest. Empirical studies in birds indicate that pair coordination of the nest visits is common; however, it is unknown whether this behaviour is directly related to different outcomes of sexual conflict, such as brood desertion. We used the rock sparrow, Petronia petronia, a species with high levels of sexual conflict, to explore whether alternation and synchrony of the nest visits were related to later brood desertion. Pairs with no desertion alternated and synchronized their nest visits more than pairs in which one sex deserted. This difference in coordination was not simply a by-product of differences in provisioning by the parents. Synchrony of the visits also increased with offspring age in the pairs with no desertion. We provide evidence, for the first time to our knowledge, that the degree of parental coordination is strongly associated with the ultimate consequence of sexual conflict, brood desertion, supporting the idea that coordination in parental behaviour might promote conflict resolution.