A Social Carnivore
Last Update/Review: May 27, 2002
The gray wolf (correct common name) or timber wolf (as northern Canadians like to call it) is the largest of the Canidae, or dog family. It successfully adapted to a wide range of habitats and historically roamed over most of the northern hemisphere. On our continent, it thrived in the tundra of high Arctic islands, throughout the diverse forests of the mainland, and on the interior plains south to Mexico. Its range may have been greater than for any other terrestrial mammal.
Although regional variation did occur, wolves were quite similar in essential features. This similarity suggests continual integration, which was no doubt maintained by the long-distance dispersals of sub-adult wolves. Tags and modern electronic gear have helped biologists to document wolf movements of hundreds of kilometres.
The wolf in Alberta is among the largest of its species, a characteristic it shares with other wolves of the northwest. For example, Alberta wolves are about 40 percent heavier, on average, than wolves in the Great Lakes region of the east. Average winter weights in Alberta are 48 kg (110 lb.) for adult males and 41 kg (91 lb.) for adult females. Many of the largest skulls measured for North American wolves are from Alberta specimens.
M. Gibeau photo |
Where snow is deep, a wolf pack trails behind its leader. In environments altered by people, wolves often use roads and snowmobile tracks for ease of travel. Territories of the Blackstone/Brazeau wolf pack were larger during winter (---) than summer (—). |
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The wolf's evolution favored characteristics that ensured the greatest success in the hunt and long-term survival. Long legs and a deep narrow chest allow far-reaching travels in search of the next meal. Keen eyesight, smell and hearing, large body size and massive canines enable wolves to detect, attack and pull down large mammals.
The wolf pack, a cohesive family-group, travels, hunts and rests together. Packs commonly include a pair of breeding adults and their pups, as well as yearlings or extra adults. The number of wolves in packs varies from 2 to more than 30, but most packs number between 5 and 12 wolves. Where the principal prey is larger, such as moose or bison, there is a tendency for packs to be larger.
The exclusive territories of breeding wolf packs serve to divide prey resources into portions distributed among the wolf population. This spacing is accomplished by a pack advertising its presence through scent marking or, if unavoidable, through aggressive encounters. During times of food shortage, a pack's territory may be invaded by neighboring wolves, which may lead to fighting and killing of their own kind. Wolf territories range in size from 50 to over 2000 km. Where prey are migratory, such as with certain northern caribou herds, the territories or ranges used by wolves are the largest.
The social nature of wolves is advantageous for a carnivore that attacks and pulls down animals bigger than itself. A pack hunts and attacks as a team. The young are taught coordinated search and attack strategies during their first summer or fall. Howling is a form of communication that helps pack members stay in touch with each other; this facilitates pack splitting and reformation.
Old or debilitated wolves may be ejected from their pack. These lone animals may follow at a distance or seek out a living between pack territories. Loners typically form less than 15 percent of the wolf population. A good example was a radio-collared female in a study pack in the Brazeau Range of western Alberta in 1983. "Dolly," as she was called by the research team, was part of a small pack of four wolves that, surprisingly, killed moose as well as their major prey, mule deer. Adult moose can be formidable, and may force hunting wolves to test several moose before attacking. It was probably during one of these encounters with moose that Dolly suffered an injury. She developed a bad limp and soon lagged behind. During the first winter observations, her pack mates rested often and even backtracked to check on her. But in the second winter, when the pack numbered nine, she fell behind for good. She followed the pack, feeding on several of its kills. She finally left her old territory and took up a new range where she survived for at least one more year and probably longer.
