Male feeding contribution facilitates multiple brooding in a biparental songbird

Abstract

Despite the cost of lost mating opportunities, biparental care is routinely observed across different groups of animals. Theory predicts that paternal care will increase reproductive success, yet many empirical studies have failed to find a direct link. Most studies have focused on the effect of paternal care on current breeding attempts, but male contributions may benefit future reproduction. Species producing clutches or litters more than once per season (i.e. multiple breeding attempts per season) are suitable for investigating whether paternal care contributes to current or future reproductive success, or both. We investigated the importance of the male's feeding contribution to multiple brooding in Japanese Tits Parus minor in northern Japan, where approximately 50% of pairs were known to reproduce multiple times within a breeding season. Male feeding contribution (proportion of provisioning delivered by the male) was positively correlated with the probability of the female multiple brooding and with nestling body mass. However, it was not correlated with fledging success in the current breeding attempt. Our results demonstrate the importance of male parental care for annual reproductive success in this multi-brooded species and provide insights into the evolution of biparental care.