Assessing genetic variation and population structure of invasive North American beaver (Castor Canadensis Kuhl, 1820) in Tierra Del Fuego (Argentina)

Abstract

The North American beaver (Castor Canadensis) was introduced into Isla Grande de Tierra del Fuego, Argentina in 1946 as a potential source of wild fur. The species showed high growth potential, reaching close to 100,000 individuals from an original founding stock of 25 females and 25 males. Beavers adapted rapidly to their new environment and became invasive, providing an excellent model of successful adaptation of introduced populations to a new habitat. In this study, we used polymorphic mitochondrial (mt) DNA to evaluate genetic variation in the introduced beaver population from Tierra del Fuego. Nucleotide variation in partial sequences of Cytochrome b (500 bp) and 12S rRNA (421 bp) genes and the main non-coding D-loop region (521 bp) were analyzed. Our study allowed to identify 10 different mtDNA lineages in the invasive population, none of them shared among the source populations. The pattern observed is a consequence of cessation of gene flow following expansion of the founding beaver population since the time of its introduction. This approach contributes to the understanding of effects of genetic changes on survival ability and reproductive success of invasive species. It also has important management implications to invasive species.

Distinguishing ecological from evolutionary approaches to transposable elements

“…For example, Lizarralde et al . () identified 10 genetic lineages different from the original source population. In this case, the researchers investigated the evolution of this population while setting aside questions about the influence of particular ecological factors.…”

“…Other investigators have focused exclusively on the genetic changes that this population has undergone over the 40 years since its introduction. For example, Lizarralde et al (2008) identified 10 genetic lineages different from the original source population. In this case, the researchers investigated the evolution of this population while setting aside questions about the influence of particular ecological factors.…”

Landscape Genetics of American Beaver in Coastal Oregon

“…Those factors, and the variations in landscapes inhabited by beaver, suggest that beaver dispersal could vary significantly across their range. More generally, genetic structure can provide insights into the scale at which gene flow and dispersal occur, but genetic studies of beaver to date (Crawford et al 2008 b , Lizarralde et al 2008) have not systematically addressed dispersal and population connectivity as a function of landscape structure.…”

“…The American beaver ( Castor canadensis ; beaver) was overharvested and locally extirpated during the sixteenth through nineteenth centuries (Kebbe 1960). This legacy sometimes overshadows the successful restoration of beaver populations throughout North America in the twentieth century and the potential for beaver to colonize empty habitat through dispersal (Lizarralde et al 2008). Although there is no known estimate of beaver population size in North America, beaver currently are managed as furbearers with established seasons and bag limits for trapping or hunting in every state of the continental United States and all Canadian provinces, and this species is considered stable and of least concern by the International Union for Conservation of Nature (Cassola 2016).…”

“…Efforts to reestablish beaver for stream restoration or harvest, relocate individuals involved in human‐wildlife conflict, or control the spread of beaver where they are non‐native (Lizarralde et al 2008, Parker et al 2012) should consider the dispersal potential of beaver. Otherwise, nuisance beaver may return, translocations may occur needlessly in places where natural dispersal would serve, or control efforts might be inappropriately distributed.…”