Data from: Genetic diversity does not explain variation in extra-pair paternity in multiple populations of a songbird

Many songbirds are socially monogamous but genetically polyandrous, mating
with individuals outside their pair bonds. Extra-pair paternity (EPP)
varies within and across species, but reasons for this variation remain
unclear. One possible source of variation is population genetic diversity,
which has been shown in interspecific meta-analyses to correlate with EPP
but which has limited support from intraspecific tests. Using eight
populations of the genetically polyandrous red-winged blackbird (Agelaius
phoeniceus), including an island population, we investigated whether
population-level differences in genetic diversity led to differences in
EPP. We first measured genetic diversity over ten microsatellite loci and
found, as predicted, low genetic diversity in the island population.
Additional structure analyses with multilocus genotypes and mtDNA showed
the island population to be distinct from the continental populations.
However, the island population’s EPP rate fell in the middle of the
continental populations’ distribution, while the continental populations
themselves showed significant variation in EPP. This result suggests that
genetic diversity by itself is not a predictor of EPP rate. We discuss
reasons for the departure from previous results, including hypotheses for
EPP that do not solely implicate female-driven behavior.