Northwest passages: conservation genetics of Arctic Island wolves

Abstract

Wolves in the Canadian Arctic Archipelago face several challenges to persistence: a harsh habitat, an unstable prey base, and potentially significant anthropogenic influences. These external factors, if combined with genetic constraints common to island populations, could be particularly difficult to withstand. To determine the genetic status of Arctic Island wolves, we used 14 microsatellite loci to estimate population variation and the extent of interisland and island-mainland gene flow. All island populations were significantly less variable than mainland wolves; although inbreeding is currently insignificant, the two least variable populations, Banks and the High Arctic (Ellesmere and Devon Islands), showed genetic signatures of recent population declines. Recovery after a bottleneck appears to result, in large part, via recolonization from other islands. These extinction-recolonization dynamics, and the degree of similarity among island wolves revealed by Bayesian clustering, suggest that Arctic Island wolves function as a metapopulation. Persistence of the metapopulation may be supported by periodic migration from mainland populations, occurring primarily through two corridors: Baffin Island in the Eastern Arctic, and Victoria Island in the Western Arctic. This gene flow could be compromised or eliminated by loss-due to climatic warming or increased human activity-of sea ice in the Northwest Passage.

An Account of the Taxonomy of North American Wolves From Morphological and Genetic Analyses

“…Islands sampled for C. 1. arctos were grouped together in a neighbor-joining distance analysis based on autosomal microsatellite data (Carmichael et al 2008, figure 3B), but the authors observed that the island populations exhibited only one private allele, and that their unpublished mtDNA data did not identify any …”

Exploring the diet of arctic wolves (Canislupusarctos) at their northern range limit

“…Despite some taxonomic controversy regarding sub-species delineation, both cranial measures (Krizan 2005) and genetic data (Carmichael et al 2008) separate Arctic wolves from southern populations (Nowak 2003). While the grey wolf is one of the most wellstudied carnivores on Earth (Brooke et al 2014), ecological data on Arctic wolves are scarce.…”

Monozygotic Twin Wolves with Divergent Life Histories

“…Therefore, while some close relatives may be included in our study, we suggest the heterozygosity of TU9291 and SH9201's genotype makes identity through inbreeding unlikely. Furthermore, Carmichael et al (2007b) showed that inbreeding is rare or absent in this population.…”

“…Bayesian estimation suggests a total, bi-directional migration rate of 1.76% between Banks Island and all northern mainland wolf populations (Western Woods; Forest; Western Barrens, including the Cape Bathurst region; Eastern Barrens; and Atlantic; Carmichael et al, 2007b), underscoring the unusual nature of this event.…”

“…Since Banks Island wolves are less variable than their mainland counterparts (Carmichael et al, 2007b), a mating between related individuals could also produce offspring that are genetically indistinguishable at the loci used here without being monozygotic twins. However, because 7 of 14 loci in this particular genotype are heterozygous, the chance that a sibling mating would produce identical, non-twin offspring was 4.25E-12 (Futuyma, 2005).…”