The grey wolf is the world’s largest wild dog species, with the male generally taller than the female. Northern populations tend to be bigger than their southern counterparts.
The grey wolf resembles a domestic dog, such as a German shepherd or a sled dog, but has longer legs, bigger paws and a narrower chest. Its thick coat consists of an outer layer of coarse guard hairs and a soft undercoat that protects the wolf against the cold. The most common coat colour is a mottled grey, but it can vary from white to red, brown or black.
Although capable of sprinting at up to 70 kilometres per hour, the wolf excels at long-distance running, averaging 5 to 10 kilometres per hour. A wolf can travel up to 70 kilometres a day while on the hunt.
Habitat and behaviour
The grey wolf populates a variety of habitats, including forests, tundra, deserts, plains and mountains.
The wolf tends to live in packs. Each pack is typically made up of an alpha pair (the dominant male and female) and their cubs, as well as offspring from previous years. Within the pack, there is a clear hierarchy that determines, among other things, which animals eat first. Generally, only the alpha pair mates, but every member of the pack helps raise the new pups. Lesser-ranked wolves are often designated “babysitters” while the rest of the pack is out hunting. Grey wolves usually mate for life.
Rank is communicated among the pack through facial expressions and body language, including crouching, flattening or straightening the ears, tucking in the tail and rolling over to show the underbelly. A pack can include up to 36 wolves when prey is plentiful but more commonly numbers between 5 and 12, although pairs and lone wolves do occur.
An opportunistic carnivore, the grey wolf prefers large ungulates, such as deer, moose, elk, caribou, muskox, mountain sheep and mountain goats. Since most of its prey can outrun it, the pack relies on a co-operative hunting strategy and surprise attacks. Pack members either take turns chasing the prey to tire it or split up and drive it into an ambush. Wolves help keep prey populations healthy by targeting the weak, old and sick.
A wolf’s mournful howl is one of its most distinguishing characteristics — the unequivocal call of the wild. Through howling, pack members can communicate with one another when separated, warn other packs away and form social bonds.
About two centuries ago, the grey wolf was the most widely distributed mammal in the world, living throughout North America, Europe and Asia. But because of factors such as hunting and habitat loss, the wolf’s range has been greatly reduced, and it is now most commonly found in the more northern regions of Canada and the United States, as well as northern Russia and China.
A wolf follows its prey, and a pack’s range can cover anywhere from 75 to 2,500 square kilometres, depending on the abundance of prey.