The first gray wolf, Canis lupus, is thought to have migrated to North America from Asia about 750,000 years ago, long before mankind arrived around 18,000 years ago. Wolves at one time ranged over most of North America north of Mexico City. Lewis and Clark reported the gray wolf, which they described as the “large wolf” to distinguish it from coyotes, as “very numerous”, feeding on bison and wild turkeys and howling through the night. Due to increasing human habitation and agriculture, wolves’ numbers have been drastically reduced. Now there are an estimated 7,000 to 11,200 gray wolves in Alaska and about 5,000 in the contiguous United States, but the number is rapidly growing due to Yellowstone’s reintroduction of wolves. They exist in pockets in Alaska, Canada, Idaho, Michigan, Minnesota, Montana, Wisconsin, Wyoming, Arizona and New Mexico.
Wolves live in packs of from about 4 to 7 members, consisting of the mated alpha male and female, their offspring, and other subordinate animals. Packs defend territories where they hunt, breed, and raise their offspring. Mating season occurs in January and February and litters of 4 to 7 pups are born after 63 days. Pups are born blind and are fed and cared for by the pack for about 10 months. When wolves become separated from their packs they howl to gather all the members together. They do not howl at the moon, but tend to howl more on light nights than on dark ones.Gray wolves are related to domestic dogs, Canis lupus familiaris, and have been compared in shape with German shepherds and malamutes. They usually range in size from 41 to 63 inches in length and 32 to 34 inches at the shoulder. Most wolves in North America weigh about 55 to 130 pounds, with males typically weighing 5 to 10 pounds more than females. Their fluffy fur is good at keeping in heat, and can be black, gray, or white. About half the wolves in Yellowstone Park are black. Their forepaws have five toes while their rear paws have four toes and a dewclaw.
Wolves are carnivores that hunt and eat mainly elk, deer, moose, caribou, sheep and other animals. Because of predation on farm animals, wolves are considered by many ranchers and farmers to be pests to be hunted down and shot. Wolf pelts have been used to make clothing. Human habitation also cuts down upon the wolves’ range by limiting their territory and food supply, replacing elk and moose with protected farm animals.
By the 1930’s there were no wolves in the western United States. In 1973 wolves were listed as endangered under the Endangered Species Act and as such were protected. Gradually the population of wolves began to recover.
Yellowstone Park played an important role in the recovery of wolves in the northwestern United States when 31 wolves from Canada were introduced in 1995. By 1999 eight breeding pairs were reported and 11 packs were observed by the year 2000. Wolves continued to thrive and in 2008 officials estimated that there were 124 gray wolves living in the park, and by the summer of 2010 their population had increased to 128. Whether wolves will remain on the endangered list or go back to be treated as varmits is controversial, but they are an essential part of the endangered ecosystem of Yellowstone Park, where they are at the top of the food chain as predators.
To some visitors gray wolves have replaced bears as the chief attraction to Yellowstone Park. The staff involved in Project Wolf maintains wolf-viewing areas in Lamar Valley and other regions where the animals are often seen. Wolves tend to be active at dawn and dusk, so those are the best times for spotting them. Bring a pair of binoculars and stay well out of their way. As with any wild animals in the park, do not feed them or leave food unattended. For wolves to be able to live long and healthy lives, it is important that they stay well away from people.