Factors associated with breeding site fidelity in the sex-role reversed red phalarope

Abstract When birds breed in multiple years, they can either return to their former breeding site or disperse to a new area. Consistent with theoretical predictions, the degree of breeding site fidelity often differs between the sexes in relation to the mating system of a species. However, most research has focused on species with conventional sex roles. Studying socially polyandrous species, in which typical sex roles are reversed, may provide insights into the drivers of breeding site fidelity in each sex. We color-banded 169 male and 184 female red phalaropes Phalaropus fulicarius, a species in which females compete for access to males (female access polyandry), and examined factors that predicted their return to the study area. Breeding site fidelity was relatively low, but substantially higher in males (20.7%) than in females (4.3%). For both sexes, the probability of returning was associated with local breeding performance: males that attended a nest in the study area were more likely to return than males without a nest, and females that locally bred with two males were more likely to return than those that only produced a clutch for a single male. Our findings are consistent with the prediction that site fidelity should be male-biased in species with a female-access polyandrous mating system. Our study also highlights that breeding site fidelity is associated with local breeding success, even in a species that shows a reversal of typical sex-roles, where individuals do not defend a territory, and breed in an environment that is highly unpredictable between years.