Genetic diversity, differentiation and historical origin of the isolated population of rooksCorvus frugilegusin Iberia

Current bird populations in southern temperate latitudes often represent relicts of glacial refugia from which northern populations expanded as the climate became suitable following the last glacial maximum, 18 000 years before present. Alternatively, these southern populations could be the result of the fragmentation of large distributions and other processes not related to glaciations, like recent recolonization from northern populations and human impact in historical times. Here, we investigate the origin of a small, isolated population of rooks Corvus frugilegus in north-western Iberia. We use genetic data from mitochondrial sequence markers and seven microsatellite loci to assess levels of genetic diversity, structure and gene flow among extant populations in Iberia and its broad distribution across western Europe. Microsatellite markers revealed the existence of two genetic clusters corresponding to Iberia and the remaining European populations, respectively. Haplotype networks ba...