The mechanisms behind expansions of the distribution of a bird species and the ensuing establishment of new populations are poorly known. The distribution of Great Grey Owl ( Strix nebulosa ) in the western Palearctic has generally expanded towards southwest during the past fifty years, and particularly so in Fennoscandia. In the past decade, the recorded breeding population in Norway, confined to Hedmark county bordering Swed...

We investigated the distributions and routes of colonization of two commensal subspecies of house mouse in Norway: Mus musculus domesticus and M. m. musculus . Five nuclear markers ( Abpa , D11 cenB2 , Btk , SMCY and Zfy2 ) and a morphological feature (tail length) were used to differentiate the two subspecies and assess their distributions, and mitochondrial (mt) D‐loop sequences helped to elucidate their colonization history...