Analysis of the American mink (Neovison vison) harvest decline and genetic introgression

Abstract

The American mink (Neovison vison) is endemic to North America where they have been domesticated over the course of 150 years by the fur industry. These domestic mink have been escaping from farms around the world and in North America while the harvests of wild mink across Canada are in decline. In this thesis, I used a combination of environmental data, spatial data, and genetics to better understand the declines. A multiple linear regression and a tree regression indicated that muskrat harvest growth rate, road density, and annual precipitation had the most effect on the mink harvest. To study the genetic introgression of domestic and wild mink, a 300 basepair fragment of the mitochondrial control region was used to determine regional differences between the wild and domestic populations of Nova Scotia and Ontario. Color differences and the direction of introgression were also studied. Significant differences between Nova Scotia wild, Ontario wild, and domestic mink were found. A pairwise ɸst test was used to determine directional introgression and resulted in an introgression of the hybrids towards the wild population. Together these results provide a better understanding of the decline in mink harvest although further research is needed to assess the direct impact of domestic escapees on the environment and on the wild population in North America. Prevention of domestic escapees is needed to stop hybridization which is important for the preservation of the species and to prevent further risk of outbreeding depression.