Reproductive performance links to fine-scale spatial patterns of female grey seal relatedness

Fine-scale spatial patterns of female relatedness throughout the established grey seal breeding colony of North Rona, Scotland, were investigated by accurate mapping and spatially explicit analyses of a large sample (n = 262) of mothers using variation at nine microsatellite DNA loci. Local spatial autocorrelation analyses identified locations where seals were more highly related to the colony than average. These locations were also areas where the more successful females bred, were occupied first during each breeding season, were centrally placed locations of preferred habitat types and were likely to be the locations which were the first to be colonized historically. Mothers occupying such sites achieved higher than average pup growth rates, suggesting a founder fitness benefit.