Brood desertion in Kentish Plover Charadrius alexandrinus: an experimental test of parental quality and remating opportunities

Abstract

Uniparental male care combined with polyandry is rare in birds, and the best known examples are in shorebirds Charadrii. There are two current hypotheses explaining why males care for the brood, whereas females desert and remate: either males are more capable than females at providing uniparental care (“parental quality hypothesis”) or females gain a greater increase in reproductive success by deserting than do males (“remating opportunity hypothesis”). I experimentally tested both hypotheses in Kentish Plover Charadrius alexandrinus, one of the few avian species in which either parent may desert the brood. By experimentally removing one parent when the chicks hatched, I found that male‐tended broods had better survival than female‐tended ones, particularly up to 6 days after hatching. It is unlikely that differential brood mortality was caused by chilling of the chicks, since the brooding behaviour of males and females was not different. The results of this study are consistent with the explanation that male‐tended broods survived better because males were better able to protect the brood from attacks by conspecifics and predators. The remating opportunity hypothesis was also corroborated because single females acquired new mates faster than did single males. The results of this study suggest that both the better parental capability of males and the greater remating opportunities of females predispose Kentish Plovers for uniparental male care, desertion by the female parent and sequential polyandry.