Assessing the cryptic invasion of a domestic conspecific: American mink in their native range

Abstract

Control of invasions is facilitated by their early detection, but this may be difficult when invasions are cryptic due to similarity between invaders and native species. Domesticated conspecifics offer an interesting example of cryptic invasions because they have the ability to hybridize with their native counterparts, and can thus facilitate the introgression of maladaptive genes. We assessed the cryptic invasion of escaped domestic American mink (Neovison vison) within their native range. Feral mink are a known alien invader in many parts of the world, but invasion of their native range is not well understood. We genetically profiled 233 captive domestic mink from different farms in Ontario, Canada and 299 free-ranging mink from Ontario, and used assignments tests to ascertain genetic ancestries of free-ranging animals. We found that 18% of free-ranging mink were either escaped domestic animals or hybrids, and a tree regression showed that these domestic genotypes were most likely to occur south of a latitude of 43.13°N, within the distribution of mink farms in Ontario. Thus, domestic mink appear not to have established populations in Ontario in locations without fur farms. We suspect that maladaptation of domestic mink and outbreeding depression of hybrid and introgressed mink have limited their spread. Mink farm density and proximity to mink farms were not important predictors of domestic genotypes but rather, certain mink farms appeared to be important sources of escaped domestic animals. Our results show that not all mink farms are equal with respect to biosecurity, and thus that the spread of domestic genotypes can be mitigated by improved biosecurity.

Landscape genetics of the nonnative red fox of California

“…Development of effective management strategies is often hindered by lack of understanding about the population structure, including connectivity, specific routes of spread, relative roles of reproduction or immigration in sustaining local populations, and potential for interbreeding with native populations. Genetic tools provide a means of elucidating points of introduction, identifying hybridization with native relatives, as well as reconstructing routes of spread and assessing the relative roles of continued immigration versus reproduction in sustaining local invasive populations (Hampton et al 2004;Lecis et al 2008;Kidd et al 2009;Berry and Kirkwood 2010;Estoup and Guillemaud 2010;Sacks et al 2011;Beauclerc et al 2013;Fraser et al 2013).…”

Misleading interpretation of shifting baseline syndrome in the conservation of European mink

“…Moreover, a successful introduction is hardly improbable just by smuggling only a few animals, especially when we consider the low rate of success of modern reintroduction-reinforcement campaigns (Põdra et al 2013a, b;. Even highly successful invaders as American mink have not been capable to establish in some areas where low number of individuals is introduced to the wild (Beauclerc et al 2013). Without doubt, capturing live mink and transporting them in the XIX century would have been expensive, and in order to be profitable we should expect a flourishing mink-fur industry to have developed in France, subsequent to the introduction, which was not the case.…”

Hybridization of domestic mink with wild American mink (Neovison vison) in eastern Canada

“…Bowman et al (2007) first showed that the signature of escaping domestic mink could be detected across Canada in wild mink harvest data. Subsequently, studies in Ontario, Canada used genetic methods to document the extent of escaped domestic mink (Kidd et al 2009;Beauclerc et al 2013). For example, 78% of free-ranging mink sampled in the Niagara Falls area were either domestic or domestic-wild hybrids (Kidd et al 2009).…”

“…The biotic effects of feral mink should differ somewhat in North America compared to other locations, owing to the occurrence of native conspecific mink. Sampling in Ontario has shown that escaped domestic mink hybridize with wild mink (Kidd et al 2009;Beauclerc et al 2013), which may lead to outbreeding depression due to a loss of local adaptation (Bowman et al 2007;Beauclerc et al 2013). An interface for potential pathogen transfer exists when there are lapses in biosecurity on mink farms.…”

“…Other than the two recent studies in Ontario (Kidd et al 2009;Beauclerc et al 2013), there are no studies evaluating the effects of escaping domestic mink on wild mink or other biota in North America. More broadly, there have only been three studies of the population genetic structure of native American mink anywhere in North America (Belliveau et al 1999; D r a f t Stevens et al 2005;Beauclerc et al 2013). Therefore, studies of population genetics of mink in other North American jurisdictions are warranted.…”