The IUCN Red List classifies the Eastern wolf as Threatened and Critically Endangered. Its fur is typically a greyish brown color variegated with shades of cinnamon red. Unlike other North American wolves, the eastern wolf produces melanistic specimens only rarely.
Similar to the red wolf, the eastern wolf is intermediate in size between the coyote and the northwestern wolf, with adult females weighing 23.9 pounds and males 30.3. Its average body length is between 105-125 cm, while that of the tail is 39-48 cm, leading to an overall length between 150 and 180 cm.
Like the gray wolf, its longevity averages between 3- 4 years, with a maximum of 15. Its size seems to be correlated with its diet based on medium sized preys. It feeds mainly on medium-sized prey such as red deer and beavers, in contrast to the gray wolf which can bring down large prey such as reindeer, wapiti, elk and bison.
Territories tend to range in range from 110–185 km², and pups attain independence at the age of 15 weeks, which is much later in gray wolves. The eastern wolf population declined markedly shortly before and after the American Revolution, especially in Connecticut, where the bounty system was rescinded in 1774.
Their numbers were still fairly high in sparsely populated areas of southern New Hampshire and Maine, with wolf hunting becoming a regular occupation for pioneers and natives. In the early 1800s, few specimens remained in southern New Hampshire and Vermont.
Interbreeding with non-indigenous wolves of the park also took place along northern and eastern Ontario, in Manitoba, Quebec, and in the western Great Lakes regions of Minnesota, Wisconsin, and Michigan. Despite legal protection, there was a decline in wolf populations in the eastern region of the park from 1987-1999, with only 30 packs counted in 2000.
This decline exceeded the annual recruitment of wolves to packs, and was attributed to human killings, usually occurring when roaming wolves would leave park boundaries to stalk deer during the winter. In 2001, protection was extended to wolves near park boundaries, and in 2012, their genetic makeup returned to the relatively unpolluted levels of the 1960s.
In 2016, whole-genome sequencing of the gray wolf and the coyote revealed that the two species diversified only 6,000-117,000 years ago, and that all North American wolves possess genes dating back to coyotes. Both the eastern wolf and the red wolf were found to have the maximum amount of coyote genes among North American wolves.
This finding was reinforced by further mitochondrial DNA study and further genomic sequencing, which showed that 60% of its DNA is gray wolf and 40% coyote.