But a wolf has longer legs, bigger feet, and a narrower chest than large domestic dogs. While a domestic dog's tail may curl, a wolf's does not. In distinguishing wolf tracks from those of large dogs, size is ineffective. The usual color is not gray but light tan or cream mixed with brown, black, and white. Much of the black is concentrated on the back, the forehead tends to be brown, and the lower part of the head and body are whitish.
Wolves eat mostly mammals such as moose, elk, deer, beaver and marmot.
They were probably the major predator in the western mountain ranges for thousands of years until the later 19th century. Wolves often eat the sick, weak, diseased, injured, and the very young or old. Removing these animals supports the vigor of the prey species population. Wolves in the wild are afraid of humans and generally avoid contact with them. There are no documented instances of healthy wolves attacking humans in North America and only one instance of a rabid wolf doing so.