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

Abstract

The available scientific literature was reviewed to assess the taxonomic standing of North American wolves, including subspecies of the gray wolf, Canis lupus. The recent scientific proposal that the eastern wolf, C. l. lycaon, is not a subspecies of gray wolf, but a full species, Canis lycaon, is well-supported by both morphological and genetic data. This species' range extends westward to Minnesota, and it hybridizes with gray wolves where the two species are in contact in eastern Canada and the Upper Peninsula of Michigan, Wisconsin, and Minnesota. Genetic data support a close relationship between eastern wolf and red wolf Canis rufus, but do not support the proposal that they are the same species; it is more likely that they evolved independently from different lineages of a common ancestor with coyotes. The genetic distinctiveness of the Mexican wolf Canis lupus baileyi supports its recognition as a subspecies. The available genetic and morphometric data do not provide clear support for the recognition of the Arctic wolf Canis lupus arctos, but the available genetic data are almost entirely limited to one group of genetic markers (microsatellite DNA) and are not definitive on this question. Recognition of the northern timber wolf Canis lupus occidentalis and the plains wolf Canis lupus nubilus as subspecies is supported by morphological data and extensive studies of microsatellite DNA variation where both subspecies are in contact in Canada. The wolves of coastal areas in southeastern Alaska and British Columbia should be assigned to C. lupus nubilus. There is scientific support for the taxa recognized here, but delineation of exact geographic boundaries presents challenges. Rather than sharp boundaries between taxa, boundaries should generally be thought of as intergrade zones of variable width.

Y‐chromosome evidence supports asymmetric dog introgression into eastern coyotes

“…; Chambers et al. ). Hybridization has clearly played an important role in the evolutionary history of Canis species in eastern North America (see Wayne and Vilà ; Kyle et al.…”

Size‐assortative choice and mate availability influences hybridization between red wolves (Canis rufus) and coyotes (Canis latrans)

“…Endemic to the eastern United States, red wolves share a common ancestor with coyotes and differentiated from them in allopatry during the Pleistocene but began interbreeding with coyotes in the southeastern United States during the early 20th century, when remnant wolf populations began interacting with expanding coyote populations (Chambers, Fain, Fazio, & Amaral, 2012;Nowak, 2002Nowak, , 2003Wilson et al, 2000). By 1980, the red wolf was extirpated from the wild but, via a captive breeding program, reintroduced into eastern North Carolina beginning in 1987 (Hinton, Chamberlain, & Rabon, 2013;United States Fish and Wildlife Service [USFWS], 1989).…”

Recent occurrences of wild-origin wolves (<em>Canis</em> spp.) in Canada south of the St. Lawrence River revealed by stable isotope and genetic analysis

“…Such animals may represent nothing more than isolated oc currences of once-captive wolves or domesticated wolf-dog hybrids (prendergast 1989;Kays and Feranec 2011), particularly as an estimated 300 000 wolf-dog hybrids are kept as companion animals in the united States (Fischer 2003). Complicating the sociopolitical issues surrounding wolf re-establishment has been an unresolved taxonomy (Chambers et al 2012), lack of information on historical distribution of forms (Wilson et al 2003;Rutledge 2010a), and possible contemporary hybridization among wolves, coyotes, and dogs (vonholdt et al 2011;Stronen et al 2012;Monzón et al 2013;Way 2013).…”

“…however, Kays and Feranec (2011) recently determined that among eight animals collected in new england, most were of captive origin, although three were likely of wild origin. In addition, the assignment of free-ranging animals to specific types within the genus Canis, especially in regions of hybridization among Coyotes, domestic dogs, and wolves, is rarely obvious phenotypically (Chambers et al 2012). the origin and identity of wolf-like canids in the northeastern united States and Canada south of the St. Lawrence River can, therefore, not be assumed, although such occurrences could be significant to potential wolf re-introduction or re-establishment in these regions.…”

“…We also report on the origin of two wolves from Quebec south of the St. Lawrence River killed in 2002 and 2006 and discuss the significance of these results. Acknowledging that wolf taxonomy in north America remains controversial, we follow a three-species model (Chambers et al 2012;Rutledge et al 2012) that includes the Gray Wolf (Canis lupus), eastern Wolf (C. lycaon), and Coyote (C. latrans), and their hybrids, rather than the more traditional twospecies approach, C. lupus and C. latrans (Koblmüller et al 2009;vonholdt et al 2011).…”