Eastern wolves, which used to live in the northeastern United States, but now remain only in southeastern Canada, qualify as a distinct species from their western cousins, according to a review by U.S. Fish and Wildlife Service scientists.
The finding may be important for the future of North American wolves and could help scientists understand how the animals evolved, as noted by USA Today (opens in new tab).
In the study, published in October in the journal North American Fauna, the scientists reviewed decades of research on North American wolves, much of it complicated and contradictory. Some studies found 8 subspecies of gray wolves; others suggested as many as 27.
Previously, scientists considered eastern wolves a subspecies of gray wolf, Canis lupus lycaon (pronounced LY-can). However, the new review of reams of genetic data suggests that the animal should be classified as a separate species of wolf entirely.
A tale of three wolves
Eastern wolves would join two universally recognized species of wolves in North America: gray wolves (Canis lupus) and red wolves (Canis rufus). Gray wolves once ranged throughout most of modern-day America, but were hunted and poisoned to the brink of extinction, maintaining only a single population in northern Minnesota, the study noted. The animals have since recovered slightly and been reintroduced to Wyoming's Yellowstone National Park (although hunting has since resumed in Minnesota, Wyoming and elsewhere).
Red wolves were also wiped out from their native range, but have been reintroduced into North Carolina and are thought to be breeding in the wild, according to news reports.
The study found that eastern wolves are most closely related to red wolves, and that both species evolved from a common ancestor shared with coyotes. This helps explain why eastern wolves can still mate with and form hybrid offspring with coyotes, so-called "coywolves." Gray wolves, on the other hand, are known to kill any coyotes they come across.
Smaller than their western cousins, eastern wolves weigh from 62 to 77 pounds (28 to 35 kilograms), according to the study. They preferentially prey on white-tailed deer, unlike gray wolves, which have a more wide-ranging diet, USA Today reported.
According to USA Today, the recent study lends support to an account made by Charles Darwin in his 1859 book "On the Origin of Species," in which he wrote: "There are two varieties of the wolf inhabiting the Catskill Mountains in the United States, one with a light greyhound-like form, which pursues deer, and the other more bulky, with shorter legs, which more frequently attacks the shepherd's flocks."
This had looked like another one of Darwin's mistakes, but the recent study suggests his words may have been prescient.
The study could impact the reintroduction of wolves in North America, as it may not be appropriate to move eastern wolves into areas where they weren't previously found, for example. However, study's potential uses remain far from clear.
The authors are careful to state that their findings don't have any bearing on the actions of the U.S. Fish and Wildlife Service, which delisted gray wolves from the Endangered Species List in the Great Lakes in 2011, according to USA Today.