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Gray Wolf Physiology

Scientific name: Canis lupus
Kingdom: Animal
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Carnivora
Family: Canidae

Description: Length 4.5 to 6 feet, including tail; Height 26 to 34 inches at the shoulder; Weight 70 to 110 pounds - females generally 5 to 10 pounds lighter than males; Coloration ranges from white to black with combinations between with gold, tan, brown and rust (a single litter can contain a variation of colors).

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Historic Ranges: Most of the northern hemisphere, throughout the world to the southern borders of Chihuahua and Durango in Central America.

Present Range: Stable throughout Canada and Alaska. Stable in the Great Lakes (Minnesota, Wisconsin and Michigan). Reintroduction has been biologically successful in Idaho and Yellowstone National Park. Ongoing efforts have been underway to restore Mexican gray wolves to Arizona and New Mexico since 1998. Red wolf reintroduction efforts in The Great Smoky Mountains were called to a halt in October of 1998 due to an insufficient prey base. Red wolves have been successfully reintroduced into the Alligator River National Refuge in North Carolina.

Reproduction: Wolves breed once a year. Their breeding season is usually January through February. The mother gives birth 63 days later, roughly in April or May, to a litter of 4 to 8 pups, each weighing about 1 pound. The pups are born in a den, where they will stay for the first 6 to 8 weeks of their life. When the pups are first born they cannot see, hear or maintain warmth and they need constant care from their mother. By to 8 weeks of age, the pups will venture out of the den and begin their life of learning how to be a predator.

Habitat: Nearly all habitats except tropical rain forests and arid deserts.

Status: Gray wolves are soon to be delisted throughout most of the conterminous United States. The Mexican gray wolf will remain protected under the Endangered Species Act in the Southwest. Red wolves will remain protected in the Southeast.

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Diet: Consists primarily of members of the deer family: moose, deer, elk and caribou. Wolves also eat beaver, rabbits and mice.

Life span: Roughly 6 - 10 years in the wild. They can live up to 18 years in captivity.

Wolves are superbly constructed and adapted for their particular role in an ecosystem - predators that pursue a large and small prey over different kinds of terrain: open plains, dense forest, deep snow, steep slopes and into the water if need be. Wolves have developed lean, muscular bodies set on long, powerful legs to be able to pursue prey. Wolves are built for endurance and running; they can average around 25 miles per hour for several miles and 35 to 40 miles per hour for short bursts. The wolf's expert hunting ability comes from a combination of speed, stamina and strategy. Because wolves have narrow chests and outward – splayed forelegs, their hind legs can move in the same track as their front legs – an advantage in covering ground efficiently. Wolves' large, well-padded feet help to spread their weight over snow and allows them to efficiently grip irregular surfaces like rocks and logs.

The sagittal crest (the bone on the top of the skull) on a wolf is where the jaw muscles are attached. This is well defined on the wolf because of their very powerful jaw. Wolves' jaws produce immense power - a crushing pressure of about 1,500 pounds per square inch (psi), compared with 750 pounds for average large dogs such as German Shepherds. Wolves have 42 teeth specialized for stabbing, shearing and crushing bones. The first four teeth, front and bottom are called incisors and are used for nipping and gnawing meat from the bone. Wolves use their canine teeth, which can grow to be 2 inches in length, for gripping and holding itself to the prey animal. The premolars are used for slicing and grinding. The specialized molars, called carnassials are used for slicing and tearing. The last molars are used for pulverizing and grinding food.

Even more extraordinary is a wolf's sense of smell - up to 100 times greater than human beings'. Under the right conditions a wolf can smell something up to 300 yards to 1 mile away. Their hearing is excellent also. Under certain conditions, wolves can hear a howl as far as six miles away in the forest and ten miles away on the open tundra.

Biology & Ecology

Origin & Development

Range & Territory


Pack Structure


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