Phylogeography and hybridisation in the european polecat : (mustela putorius)

Tese de doutoramento, Biologia (Biologia da Conservação), Universidade de Lisboa, Faculdade de Ciências, 2014

The European polecat (Mustela putorius) belongs to the family Mustelidae and has a wide geographical distribution in the western Palaearctic. Across most of its range, polecat populations are decreasing in numbers as a consequence of habitat destruction, direct persecution, decreases in prey populations, secondary poisoning, road casualties and hybridisation with other mustelid species. The present work assessed the major phylogeographic patterns in the European polecat across its geographical range and examined the extent of hybridisation and introgression between polecats and ferrets (Mustela furo) in the British Islands. For this, a large number of samples covering a wide area of the polecat distribution in Europe were analysed, including also samples of captive domestic ferrets from mainland Britain and feral ferrets from British offshore islands. Mitochondrial DNA and microsatellites were the molecular markers used to achieve the aims of this thesis. Phylogeographic and population structure analyses suggest the existence of multiple glacial refugia for polecats in Europe, with different contributions of refugial populations to the recolonisation of central and northern Europe during interglacials. The genetic information obtained from this study provides a baseline for the definition of conservation units, which are essential in the design of an appropriate conservation management for a species with a declining population trend in many European countries. Admixture analyses provided a detailed description of the extent of introgression in the British Islands, with the eastern edge of the polecat distribution consisting mostly of a hybrid swarm, which resulted from multigenerational introgression. It also highlighted the importance of the Welsh polecat population for the conservation and restoration of the genetic identity of the British polecat.

Fundação para a Ciência e a Tecnologia (FCT, SFRH/BD/32488/2006)