What Color is a Gray Wolf?

Wolves range in color from white or cream to gray and black. The darker colors are common in wolves that live in forested areas, but rare in wolves in the Canadian tundra. Scientists have proposed that darker fur color confers a selective advantage in a forested habitat and have speculated about linked genetic advantages not related to color.

In the March 6, 2009 issue of Science (vol. 323, p. 1339), Dr. Gregory Barsh and graduate student Tovi Anderson describe the genetics of black coloration in wolves. They examined genetic variation in wolves, dogs and coyotes, and concluded that dark coloration was introduced into the wolf population from domesticated dogs. Black wolves probably started appearing shortly after the first humans (and their domesticated dogs) migrated to North America.

Humans often have disastrous effects on wolf populations. Global warming and land development reduce wolves’ habitat. It is ironic that a gene introduced to the wolf population by man’s best friend may help wolves survive.

Here is a related article in Science Daily.