There are two species of serigala in North America. The smaller species is the red wolf, Canis rufus, which has shorter, redder bulu than the gray wolf. The gray wolf, Canis lupus, has thicker bulu which is lebih gray atau golden, and is larger than the red wolf. The gray serigala lives in the northeastern United States, Canada, and Europe. The red serigala lives in the southeastern United States.
There are many subspecies of the gray wolf, such as the arctic wolf, a white subspecies which lives in Alaska and northern Canada, and the Mexican wolf, a smaller subspecies which has been recently reintroduced in parts of the southwestern United States.