Good read. The article includes the following quotations:
Development of even more powerful genetic markers has led to new, highly controversial interpretations, * * * * Other controversies include whether the current Great Lakes wolf population is evolutionarily representative of the historical population (
Leonard and Wayne 2008) * * * and the taxonomic identity of wolves of Pacific coastal regions (
Muñoz-Fuentes et al. 2009). The lack of consensus among researchers on so many important issues related to the taxonomy of North American wolves prompted the present review.
Differences in habitat have been correlated with variations in behavior, including migration and prey selection. For example, Kolenosky and Stanfield (1975) have described variation in Ontario wolves, where larger wolves of boreal forests specialize on moose Alces americanus and caribou Rangifer tarandus as prey, while smaller wolves in deciduous forest habitats specialize on white-tailed deer Odocoileus virginianus.
Trends of increasing size among wolves to the north and west of southern Ontario and Quebec have been noted in morphometric studies covering the Great Lakes region. The association of smaller wolves with white-tailed deer in deciduous forests and larger wolves with larger prey, such as moose and caribou, in boreal forests has been frequently cited (
Kolenosky and Standfield 1975;
Skeel and Carbyn 1977;
Schmitz and Kolenosky 1985). When wolf skulls were divided by source habitat into deciduous forest (eastern wolf) and boreal forest (
C. lupus), discriminant function analysis distinguished 75% of boreal wolves from eastern wolves, and boreal wolves were >25% larger in body mass (
Kolenosky and Standfield 1975).
Differences in habitat can, however, coincide with subspecies boundaries and play a role in maintaining taxonomic distinctions when ranges are contiguous. In these instances, explanations based on habitat variation can also be taxonomically informative. These coastal–inland patterns of genetic and ecological divergence lend support to
Nowak's (1995) boundary between
C. l. nubilus and
C. l. occidentalis in the Pacific Northwest.
The wolf population of coastal British Columbia was probably contiguous with the original populations of coastal Washington and Oregon, which were included by
Goldman (1944) with
Canis lupus fuscus, the type locality of which (near The Dalles, Oregon) was not coastal.
Hall and Kelson (1959) included most of coastal British Columbia with the range of this subspecies.
Bailey (1936) identified coastal wolves of Oregon as
Canis lycaon gigas (type locality near Vancouver, Washington).
Goldman (1944) included this name as a synonym of
C. lupus fuscus. Understanding the phylogenetic relationship of coastal British Columbia and southeast Alaska wolves
to other populations that Nowak (1995) included in C. l. nubilus is greatly impeded by the extirpation of that subspecies in inland portions of the western United States. Genetic study of historical remains from western Oregon and Washington
would provide additional information for the taxonomic placements of Pacific Northwest wolves that have been based on traditional morphology and morphometrics.
Nowak's (1983,
1995) classification and evolutionary explanation characterizes
C. l. nubilus as a medium-size wolf that was widespread in North America at the time of arrival of
the larger C. l. occidentalis.
It is possible that further research will provide data that would change certain conclusions reached here. Longer sequences of mtDNA (most studies used approx. 200 to approx. 400 base pairs) could provide more robust resolution of both extant and historical populations. There are many more historical specimens in museum and government agency collections that have not yet had DNA characterized. Y-chromosome haplotypes from additional populations of wolves would provide an additional lineage marker to complement mtDNA data. Single nucleotide polymorphisms are now being studied in wolves,
but most areas of North America remain sparsely sampled (
Anderson et al. 2009;
Gray et al. 2009;
vonHoldt et al. 2011).
These “fuzzy” boundaries are a consequence of lineages of wolves that evolved elsewhere coming into contact with each other. Historical or modern boundaries should also not be viewed as static or frozen in any particular time. Our understanding of the historical interactions between subspecies or genetically different populations (e.g.,
Leonard et al. 2005) is that they are dynamic processes and boundaries can shift over time. Even with the great dispersal capabilities of wolves and their interaction in these intergrade zones, genetic indications of the independent evolution of the wolves here recognized as species or subspecies are still discernible on a continental scale.
This review was initiated
because of the wide range of views expressed by different researchers and research groups on some major features of relationships and classification of North American wolves.
