North American Bears

North America's three native bear species, the American Black Bear, Brown Bear and Polar Bear belong to the genus Ursus.

Habitat destruction, hunting and other factors have limited its range over time. However, black bear populations still exist in many northern and coastal forest areas from the east to the west.

Ranging in size from four to six feet, black bears are the smallest of the three native North American bears.

They are omnivores with a keen sense of smell. During their foraging season they almost literally follow their nose to find food.

Traditional forest foods include mushrooms, tree bark and small mammals. Fans of people food and bird seed, black bears are often inclined to roam residential areas, corn fields or camp sites in search of a meal.

Black bear coats tend toward darker shades in the east, with many western bears having lighter tan or cinnamon color coats.

Black bear population estimates vary from state to state, depending on how wildlife officials do their counting. There are no exact statistics on aggregate population levels, however, recent population research suggests an overall increase in black bear populations over the last fifteen years.

The world's most widely distributed bear, the brown bear (Ursus arctos), also known as the grizzly bear, a native subspecies (Ursus arctos horriblis), inhabits most of the Northern hemisphere forest areas in North America, Europe, Russia, Asia.

Its extended range translates into population fluctuations, depending on location. For example, the IUCN lists it as endangered in Mongolia but stable in Finland and the United States.

Russia, the world's largest country by land mass, hosts the largest brown bear population. North America brown bears inhabit western forests, with Alaska home to the largest population.

Brown bear populations in the continental United States decreased significantly during the twentieth century. In 1975 they were listed as a threatened species.

Today there are five different regions in the western United States designated as recovery habitats. About ninety per cent of the grizzly population is found in two of those areas, the ecosystem that includes Yellowstone National Park and an area in north central Montana that includes Glacier National Park.

The U.S. Fish and Wildlife Service covers their status. The reintroduction and recovery process continues to spark conflict. Recently a court order changed the status of the Yellowstone population back to threatened. Reintroduction of grizzlies into the Bitterroot Ecosystem continues to be met with resistance.

Typically, brown bears grow larger than black bears, and their size is a function of their habitat. The availability of an abundant food source helps make the Alaskan brown bear, or Kodiak Bear the largest U.S. brown bear population.

Males can grow to five feet standing up and approach a weight of one thousand pounds. Their continental relatives usually measure and weigh in about twenty five percent less.

Surprisings, for their size, brown bears are primarily vegetarian, consuming a variety of plants and fruits in their large territory. They supplement their diet with small mammals and rodents. Occasionally they will prey on larger mammals such as elk or deer.

The Polar Bear (Ursus maritimus), a northern marine mammal, grows a white fur coat to help camouflage them in their natural environment.

The world's largest bears, males can grow up to ten feet tall and weigh more than 1,500 pounds. Females grow considerably smaller than males.

Mainly carnivorous, polar bear diets depend heavily on local seal populations.

Exact polar bear population estimates do not exist. Biologists estimate the number to be between twenty and twenty-five thousand individuals, with over half of them living in Canadian territory.

Growing concerns about polar bear populations are being fueled by speculation that global warming could put them at risk by melting the sea ice areas the polar bear calls home.

Recent research on polar bear population levels and sea ice loss by the United States Geological Survey concludes,

"Projected changes in future sea ice conditions, if realized, will result in loss of approximately 2/3 of the world's current polar bear population by the mid 21st century."

In 1995, the Bear Specialist Group with the IUCN placed the polar bear on the vulnerable species list.

After a thorough review of polar bear population dynamics in the context of continued sea ice loss, the United States listed the polar bear as threatened under the terms of the Endangered Species Act.

© 2001-2012. Patricia A. Michaels