US Geological Survey


Date of this Version



Published in Wolves: Behavior, Ecology, and Conservation, edited by L. David Mech and Luigi Boitani (Chicago & London: University of Chicago Press, 2003).


U.S. government work.


THE WOLF IS TRULY a special animal. As the most widely distributed of all land mammals, the wolf, formally the gray wolf (Canis lupus), is also one of the most adaptable. It inhabits all the vegetation types of the Northern Hemisphere and preys on all the large mammals living there. It also feeds on all the other animals in its environment, scavenges, and can even eat fruits and berries. Wolves frequent forests and prairies, tundra, barren ground, mountains, deserts, and swamps. Some wolves even visit large cities, and, of course, the wolf's domesticated version, the dog, thrives in urban environments.

Such a ubiquitous creature must, as a species, be able to tolerate a wide range of environmental conditions, such as temperatures from -56° to +50°C (-70° to +120°F). To capture its food in the variety of habitats, topographies, and climates it frequents, the wolf must be able to run, climb, lope, and swim, and it performs all these functions well. It can travel more than 72 km (43 mi)/day, run at 56-64 km (34-38 mi)/hr, and swim as far as 13 km (8 mi) (P. C. Paquet, personal communication), no doubt aided by the webs between its toes.