Within-Pair Copulations: Are Female Tree Swallows Feathering Their Own Nests?

Repeatability of extra-pair mating in tree swallows.

Models of sexual selection assume that female mating preferences are heritable and, thus, repeatable for individual females across multiple mating episodes. Previous studies of the repeatability of female preference have examined individuals in captivity and focused presumably on social mate choice. However, extra-pair mating is widespread and can also influence sexual selection. We examined th...

Extra-Pair Copulations and Associated Genetic Benefits

Male infertility, female fertility and extrapair copulations.

Females that are socially bonded to a single male, either in a social monogamy or in a social polygyny, are often sexually polyandrous. Extrapair copulations (EPC) have often been suggested or rejected, on both empirical and theoretical grounds, as an important mechanism that enables females to avoid fertility risks in case their socially bonded male is infertile. Here, we explore this possibil...

Are there indirect fitness benefits of female extra-pair reproduction? Lifetime reproductive success of within-pair and extra-pair offspring.

The forces driving extra-pair reproduction by socially monogamous females, and the resulting genetic polyandry, remain unclear. A testable prediction of the hypothesis that extra-pair reproduction partly reflects indirect selection on females is that extra-pair young (EPY) will be fitter than their within-pair young (WPY) maternal half-siblings. This prediction has not been comprehensively test...

Do Individual Females Differ Intrinsically in Their Propensity to Engage in Extra-Pair Copulations?

BACKGROUND While many studies have investigated the occurrence of extra-pair paternity in wild populations of birds, we still know surprisingly little about whether individual females differ intrinsically in their principal readiness to copulate, and to what extent this readiness is affected by male attractiveness. METHODOLOGY/FINDINGS To address this question I used captive zebra finches (Ta...