BROOD DESERTION IN KENTISH PLOVER CHARADRIUS-ALEXANDRINUS - AN EXPERIMENTAL TEST OF PARENTAL QUALITY AND REMATING OPPORTUNITIES

Uniparental male care combined with polyandry is rare in birds, and th e best known examples are in shorebirds Charadrii. There are two curre nt hypotheses explaining why males care for the brood, whereas females desert and remate: either males are more capable than females at prov iding uniparental care (''parental quality hypothesis'') or females ga in a greater increase in reproductive success by deserting than do mal es (''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 experime ntally removing one parent when the chicks hatched, I found that male- tended broods had better survival than female-tended ones, particularl y up to 6 days after hatching, it is unlikely that differential brood mortality was caused by chilling of the chicks, since the brooding beh aviour of males and females was not different, The results of this stu dy are consistent with the explanation that male-tended broods survive d better because males were better able to protect the brood from atta cks by conspecifics and predators. The remating opportunity hypothesis was also corroborated because single females acquired new mates faste r than did single males. The results of this study suggest that both t he better parental capability of males and the greater remating opport unities of females predispose Kentish Plovers for uniparental male car e, desertion by the female parent and sequential polyandry.