Females of a socially polyandrous, sex-role reversed shorebird visit multiple breeding sites within a single season

Abstract

In species with uniparental care, the non-caring sex is expected to pursue mating opportunities throughout the breeding season to maximize reproductive success. Accordingly, males in some socially polygynous species have been observed to visit multiple potential breeding sites within a breeding season, often covering large distances. In socially polyandrous species, females typically search for additional mating opportunities after having laid a clutch for a male, but whether they move between breeding areas remains largely unknown. We tracked the movements of 21 female Eurasian dotterels, a sex-role reversed shorebird in which parental care is typically performed by the male alone, although females contribute to incubation at some nests. We found that females visited up to five sites (median: three) and travelled up to 1000 km between consecutive sites (median: 71 km). Movements during the early breeding season were primarily northwards, but females remained at a similar latitude later in the season. Females stayed longer at their final site (median: 41 days) than at other sites (median: 6 days), suggesting that they may switch to investing in parental care when mating opportunities are no longer available. Our findings support the hypothesis that females of socially polyandrous species may pursue mating opportunities and potentially lay clutches across multiple breeding sites within a single season.