The term "tundra wolf" can refer to three different subspecies of the gray wolf species known as Canis lupus. Tundra wolves are generally larger than other gray wolves and have thicker coats that protect them from the arctic air. In North America, the Alaskan tundra wolf and Mackenzie tundra wolf inhabit parts of Alaska and Canada. A third subspecies is found mainly in northern Europe and parts of Asia.
Alaskan tundra wolves, or Canis lupus tundrarum, live in the tundra regions near northern Alaska's coast and were classified as a subspecies by a zoologist named Gerrit Smith Miller in 1912. Most have white or light gray coats, although some have darker-colored fur. Adults grow to be 50 to 64 inches (127 to 162 cm) long. Females typically weigh between 80 to 120 pounds (36 to 54 kg), while males weigh between 85 to 176 pounds (38 to 80 kg).
The Mackenzie tundra wolf has been classified in the subspecies Canis lupus occidentalis since 1992. Zoologist Rudolph Anderson originally classified it as Canis lupus mackenzii in 1943. Mackenzie tundra wolves are found in the Northwest Territories of Canada near Great Bear Lake and up to the northern coast. Coat colors for this subspecies are typically white, black or gray, although they can also be a mixture of any of these shades. They measure between 60 to 65 inches (152 to 165 cm) in length when fully grown.
Robert Kerr classified the European tundra wolf as the subspecies Canis lupus albus in 1792. The range for this subspecies extends from the Kamchatka Peninsula to the northern coast of western Russia and over to Finland. Their coats are usually a blend of reddish-brown, black, gray and silver shades. Adults reach an average length of 84 inches (213 cm) and weigh between 100 to 125 pounds (45 to 57 kg).
Tundra wolves are skillful hunters that are able to catch large prey when hunting in packs. Alaskan tundra wolves prefer to feed on deer, while Mackenzie tundra wolves mainly eat caribou. European tundra wolves eat a variety of large mammals, including bison, moose, musk ox and wapiti. Tundra wolves will also prey on smaller mammals, such as rodents, when hunting by themselves or when larger prey isn't available.