Overview

There are two main species of wolf in North America: the red wolf (Canis rufus), and the gray wolf (Canis lupus). The red wolf is limited to the southeastern United States. The gray wolf ranges from the area around the U.S./Canadian border almost all the way to the North Pole.

At one time, 24 subspecies of wolf was recognized, based on regional variations in overall size, color, and skull configuration. However, wolves are travelers and movement of wolves across regional borders and interbreeding between subspecies has blurred the distinction between types.

Today, many scientist divide gray wolves into five subspecies, and names such as Eastern timber wolf and Rocky Mountain wolf describe geographic origin rather than physical characteristics. Gray wolves are citizens of the world, and basically are all much the same.

An average-size North American male gray wolf might weigh 95 to 100 pounds, stand 30 to 32 inches at the shoulders, and stretch six feet from nose to the tip of the tail. Females are about 20 percent smaller. A big wolf might weigh 120 pounds and stretch six and a half feet.

Gray wolves come in all shades of gray, tan, brown, rusty red, cream, buff and solid black and white. About one third are black, with this color most predominant in Alaska and mid-Canada. Arctic gray wolves tend to be creamy white.

Two layers comprise the fur coat: the outer guard hairs shed water and provide the markings, while the dense undercoat provides insulation. A wolf can curl up in the snow and sleep at minus 50 degrees Fahrenheit.

Wolves roam over large territories and are built for distance running. The chest is narrow, which makes forging through snow easier, the legs are long and closely set together at the front, so that one follows the other in the same track, and the paws are large, almost the size of a man’s hand, for traction in the snow.

As befits dominant carnivores, wolves have large teeth, and jaws with a bite force of 1,500 pounds per square inch, capable of crushing the thighbone of a moose.