Simulated hatching failure predicts female plasticity in extra-pair behavior over successive broods

While many studies have investigated the occurrence of extra-pair paternity (EPP) and its adaptive significance in wild population of birds, we still know surprising little about the plasticity in mating behavior of females at the individual level and how it affects the patterns of paternity. To address this question, we focused on the direct fertility benefit hypothesis for the function of EPP and studied if female birds react in extra-pair mating behavior after reproductive failures using a wild population of the Japanese great tit, Parus minor, a socially monogamous passerine with a moderate frequency of EPP and a high multiple brooding rate. We simulated hatching failure by replacing with artificial eggs during the egg laying period to investigate if females subsequently altered their mating behavior and became more promiscuous to improve reproductive success in their following clutches. The proportion of extra-pair offspring per clutches of both experimental and control pairs incre...