The genetic impacts of barriers and Pleistocene glaciations on high latitude resident species have not been widely investigated in North America. The distribution of many resident boreal species encompasses known dispersal barriers and much of the land area covered by ice sheets during the Pleistocene. One such resident bird species, the Gray Jay (Perisoreus canadensis), is strongly associated with spruce-dominated boreal forests throughout North America. Its range includes dispersal barriers such as mountain ranges and large bodies of water and much of the range was glaciated during the last glacial maximum. Using a highly variable mitochondrial DNA marker, a range of phylogeographic analyses, and species distribution modeling, we examined the effects of glaciations and dispersal barriers on population genetic patterns and population structure of Gray Jays.
Results/Conclusions
We sequenced 914 bp of the mitochondrial control region for 175 individuals from 17 populations across the Gray Jay range. Populations were highly differentiated into a minimum of six geographically distinct mitochondrial groups with diverse histories including colonization from and prolonged isolation in multiple refugia. Paleodistribution models supported at least five areas of suitable Gray Jay habitat during the last glacial maximum. Historical climatic fluctuations, the presence of multiple dispersal barriers and highly restricted gene flow appear to be responsible for genetic diversification of Gray Jays.