Subspecies of carnivore
 ;templatestyles src="Template:Taxobox/core/styles.css" / ;
The eastern wolf (Canis lycaon or Canis lupus lycaon), also known as the timber wolf, Algonquin wolf and eastern timber wolf, is a canine of debated taxonomy native to the Great Lakes region and southeastern Canada. It is considered to be either a unique subspecies of gray wolf or red wolf or a separate species from both. Many studies have found the eastern wolf to be the product of ancient and recent genetic admixture between the gray wolf and the coyote, while other studies have found some or all populations of the eastern wolf, as well as coyotes, originally separated from a common ancestor with the wolf over 1 million years ago and that these populations of the eastern wolf may be the same species as or a closely related species to the red wolf ("Canis lupus rufus" or "Canis rufus") of the Southeastern United States. Regardless of its status, it is regarded as unique and therefore worthy of conservation with Canada citing the population in eastern Canada (also known as the "Algonquin wolf") as being the eastern wolf population subject to protection.
There are two forms, the larger being referred to as the Great Lakes wolf, which is generally found in Minnesota, Wisconsin, the Upper Peninsula of Michigan, southeastern Manitoba and northern Ontario, and the smaller being the Algonquin wolf, which inhabits eastern Canada, specifically central and eastern Ontario and southwestern Quebec, with some overlapping and mixing of the two types in the southern portions of northeastern and northwestern Ontario. The eastern wolf's morphology is midway between that of the gray wolf and the coyote. The fur is typically of a grizzled grayish-brown color mixed with cinnamon. The nape, shoulder and tail region are a mix of black and gray, with the flanks and chest being rufous or creamy. It primarily preys on white-tailed deer, but may occasionally hunt moose and beavers.
In the third edition of "Mammal Species of the World" published in 2005, the mammalogist W. Christopher Wozencraft listed the eastern wolf as a gray wolf subspecies, which supports its earlier classification based on morphology in three studies. This taxonomic classification has since been debated, with proposals based on DNA analyses that includes a gray wolf ecotype, a gray wolf with genetic introgression from the coyote, a gray wolf/coyote hybrid, a gray wolf/red wolf hybrid, the same species as the red wolf, or a separate species ("Canis lycaon") closely related to the red wolf. Commencing in 2016, two studies using whole genome sequencing indicate that North American gray wolves and wolf-like canids were the result of ancient and complex gray wolf and coyote mixing, with the Great Lakes wolf possessing 25% coyote ancestry and the Algonquin wolf possessing 40% coyote ancestry.
In the US, gray wolves including the timber wolf are protected under the Endangered Species Act of 1973, although the protections were removed at the federal level in 2021 before being reinstated in 2022. In Canada, the eastern wolf is listed as "Canis lupus lycaon" under the "Species At Risk Act 2002, Schedule 1" - List of Wildlife at Risk. In 2015, the Committee on the Status of Endangered Wildlife in Canada recognized the eastern wolf in central and eastern Ontario and southwestern Quebec as "Canis" cf. "lycaon" ("Canis" species believed to be "lycaon") and a threatened species worthy of conservation. The main threat to this wolf is human hunting and trapping outside of the protected areas, which leads to genetic introgression with the eastern coyote due to a lack of mates. Further human development immediately outside of the protected areas and the negative public perception of wolves are expected to inhibit any further expansion of their range. In 2016, the Committee on the Status of Species at Risk in Ontario recognized the Algonquin wolf as a "Canis sp." ("Canis" species) differentiated from the hybrid Great Lakes wolves which it found were the result of "hybridization and backcrossing among Eastern Wolf ("Canis lycaon") (aka "C. lupus lycaon"), Gray Wolf ("C. lupus"), and Coyote ("C. latrans")".
Taxonomy.
The first published name of a taxon belonging to the genus "Canis" from North America is "Canis lycaon". It was published in 1775 by the German naturalist Johann Schreber, who had based it on the earlier description and illustration of one specimen that was thought to have been captured near Quebec. It was later reclassified as a subspecies of gray wolf by Edward Goldman.
In the third edition of "Mammal Species of the World" published in 2005, the mammalogist listed the eastern wolf as a gray wolf subspecies, which supports its earlier classification based on morphology in three studies. This taxonomic classification has since been debated.
In 2021, the American Society of Mammalogists considered the eastern wolf as its own species ("Canis lycaon").
Taxonomic debate.
When European settlers first arrived to North America, the coyote's range was limited to the western half of the continent. They existed in the arid areas and across the open plains, including the prairie regions of the midwestern states. Early explorers found some in Indiana and Wisconsin. From the mid-1800s coyotes began expanding beyond their original range.
The taxonomic debate regarding North American wolves can be summarised as follows:
 ;templatestyles src="Template:Blockquote/styles.css" / ;There are two prevailing evolutionary models for North American "Canis":
or
The evolutionary biologist Robert K. Wayne, whose team is involved in an ongoing scientific debate with the team led by Linda K. Rutledge, describes the difference between these two evolutionary models: "In a way, it is all semantics. They call it a species, we call it an ecotype."
Paleontological evidence.
Some of the earliest "Canis" specimens were discovered at Cripple Creek Sump, Fairbanks, Alaska, in strata dated 810,000 years old. The dental measurements of the specimens clearly match historical "Canis lycaon" specimens from Minnesota.
Genetic evidence.
Mitochondrial DNA (mDNA) passes along the maternal line and can date back thousands of years.
In 1991, a study of the mitochondrial DNA (mDNA) sequences of wolves and coyotes from across North America found that the wolves of the Minnesota, Ontario and Quebec regions possessed coyote genotypes. The study proposes that dispersing male gray wolves were mating with coyote females in deforested areas bordering wolf territory. The distribution of coyote genotypes within wolves matched the phenotypic differences between these wolves found in an earlier study, with the larger Great Lakes wolf found in Minnesota, the smaller Algonquin (Provincial Park) type found in central Ontario, and the smallest and more coyote-like tweed wolf or eastern coyote type occupying sections of southeastern Ontario and southern Quebec.
In 2000, a study looked at red wolves and eastern wolves from both eastern Canada and Minnesota. The study agreed that these two wolves readily hybridize with the coyote. The study used 8 microsatellites (genetic markers taken from across the genome of a specimen). The phylogenetic tree produced from the genetic sequences showed a close relationship among the red wolves and the eastern wolves from Algonquin Park, southern Quebec, and Minnesota such that they all clustered together. These then clustered next closer with the coyote and away from the gray wolf. A further analysis using mDNA sequences indicated the presence of coyote in both of these two wolves, and that these two wolves had diverged from the coyote 150,000–300,000 years ago. No gray wolf sequences were detected in the samples. The study proposed that these findings are inconsistent with the two wolves being subspecies of the gray wolf, that red wolves and eastern wolves (eastern Canadian and Minnesota) evolved in North America after having diverged from the coyote, and therefore they are more likely to hybridize with coyotes.
In 2009, a study of eastern Canadian wolves – which was referred to as the "Great Lakes" wolf in this study – using microsatellites, mDNA, and the paternally-inherited yDNA markers found that the eastern Canadian wolf was a unique ecotype of the gray wolf that had undergone recent hybridization with other gray wolves and coyotes. It could find no evidence to support the findings of the earlier 2000 study regarding the eastern Canadian wolf. The study did not include the red wolf. This study was quickly rebutted on the grounds that it had misinterpreted the findings of earlier studies that it relied upon, nor did it provide a definition for a number of the terms that it used, such as "ecotype".
In 2011, a study compared the genetic sequences of 48,000 single nucleotide polymorphisms (mutations) taken from the genomes of canids from around the world. The comparison indicated that the red wolf was about 76% coyote and 24% gray wolf with hybridization having occurred 287–430 years ago. The eastern wolf – which was referred to as the "Great Lakes" wolf in this study – was 58% gray wolf and 42% coyote with hybridization having occurred 546–963 years ago. The study rejected the theory of a common ancestry for the red and eastern wolves. However the next year, a study reviewed a subset of the 2011 study's Single-nucleotide polymorphism (SNP) data and proposed that its methodology had skewed the results and that the eastern wolf is not a hybrid but a separate species. The 2012 study proposed that there are three true canis species in North America – the gray wolf, the western coyote, and red wolf/eastern wolf with the eastern wolf represented by the Algonquin wolf, with the Great Lakes wolf being a hydrid of the eastern wolf and the gray wolf, and the eastern coyote being a hybrid of the western coyote and the eastern (Algonquin) wolf.
Also in 2011, a scientific literature review was undertaken to help assess the taxonomy of North American wolves. One of the findings proposed was that the eastern wolf, whose range includes eastern Canada and the Upper Peninsula of Michigan plus Wisconsin and Minnesota is supported as a separate species by morphological and genetic data. Genetic data supports a close relationship between the eastern and red wolves, but not close enough to support these as one species. It was "likely" that these were the separate descendants of a common ancestor shared with coyotes. This review was published in 2012.
Another study of both mDNA and yDNA in wolves and coyotes by the same authors indicates that the eastern wolf is genetically divergent from the gray wolf and is a North American evolved species with a long-standing history. The study could not dismiss the possibility of the eastern wolf having evolved from an ancient hybridization of gray wolf and coyote in the Late Pleistocene or Early Holocene. Another study by the same authors found that eastern wolf mDNA genetic diversity had been lost after their culling in the early 1960s, leading to the invasion of coyotes into their territory and introgression of coyote mDNA.
In 2014, the National Center for Ecological Analysis and Synthesis was invited by the United States Fish and Wildlife Service to provide an independent review of its proposed rule relating to gray wolves. The Center's panel findings were that the proposed rule was heavily dependent upon the analysis contained in a scientific literature review conducted in 2011 (Chambers et al.), that this work was not universally accepted and that the issue was "not settled", and that the rule does not represent the "best available science". Also in 2014, an experiment to hybridize a captive western gray wolf and a captive western coyote was successful, and therefore possible. The study did not assess the likelihood of such hybridization in the wild.
In 2015, the Committee on the Status of Endangered Wildlife in Canada changed its designation of the eastern wolf from "Canis lupus lycaon" to "Canis cf. lycaon" ("Canis" species believed to be "lycaon") and a species at risk.
Later that year, a study compared the DNA sequences using 127,000 single-nucleotide polymorphisms (mutations) of wolves and coyotes, but did not include red wolves and used Algonquin wolves as the representative eastern wolf, not wolves from the western Great Lakes states (usually referred to as Great Lakes wolves). The study indicated that Algonquin wolves were a distinct genomic cluster, even distinct from the Great Lakes states' wolves, which it found were actually hybrids of the gray wolf and the Algonquin wolf. The study's results did not exclude a possibility that the Great Lakes states' wolf (the gray wolf x eastern wolf hybrid ("C. l. lycaon")) historically inhabited southern Ontario, southern Quebec and the northeastern United States alongside the Algonquin wolf, as there is evidence to suggest both inhabited those areas.
In 2016, a study of mDNA once