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.IAL_gen_diversity_bootstrapR script using the bootstrap to estimate three measures of genetic diversity (allelic diversity, Shannon diversity, and expected heterozygosity). Requires IAL_popsim.R and an input file of microsatellite genotypes (IAL_RWBL_genotypes.csv). Written by J. Johndrow.IAL_popsimR function needed for IAL_gen_diversity_bootstrap.R. Written by J. Johndrow.IAL_random_effects_modelR script generating random-effects model. Requires input file of extra-pair paternity rates (IAL_RWBL_EPP_allpops.csv). Written by J. Johndrow.IAL_RWBL_BahMIPA_nest_genotypesGenotypes of female, social male, and chicks at nests sampled in the Bahamas, Michigan, and Pennsylvania. These data were used to measure extra-pair paternity (EPP) in the three populations.IAL_RWBL_EPP_allpopsExtra-pair paternity (EPP) data for all eight populations, as measured by number of extra-pair young and number of nests containing at least one extra-pair young. "0" and "1" indicate a negative and positive response, respectively.IAL_RWBL_genotypesGenotypes of ten microsatellite loci for 307 red-winged blackbirds across eight populations.IAL_RWBL_ND2_sequencesSequence data for the ND2 region of mtDNA for 28 individuals (14 from the Bahamas populations and two each from the seven continental populations).IAL_RWBL_Structure_mainparamsMain parameters file for Structure runs