Multiple ancestral populations as the key to the successful colonisation of the Carpathians by Goosanders

The Eurasian subspecies of the Goosander Mergus merganser consists of three subclades (Fennoscandian–British, E European–N Asian, and Alpine). Recently, this species expressed a rapid expansion in the Carpathians. In this study, we used mitochondrial DNA to track the origins of this population. Sequencing revealed that the majority of the Carpathian birds are related to the N Polish and Russian populations, whereas one sample has a haplotype known from the Alps. This mixed ancestry was probably caused by an outbreeding enhancement and/or enlarged habitat requirements that allowed the birds to settle in the mountain rivers of the Carpathians.