Animal information sheet:

Grizzly Bear

Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Mammalia Order: Carnivora Family: Ursidae Genus: Ursus Species: Ursus arctos Subspecies: horribilis

Geographic Range Brown bears are the most widely distributed ursid. Historically, brown bear geographic range included most of North America (Canada to Mexico), Asia, Europe, and even North Africa. Populations are now restricted to Yellowstone National Park, northern Idaho, eastern Washington, northwest Montana, Alaska, Canada, Russia, northern Asia, and small parts of Europe and the Middle East. They occupy more habitats than any other species of bear, including dry Asian steppes, Arctic shrublands, and temperate rainforests. Grizzly bears are a subspecies of brown bear that occupies North America. They are most concentrated in Alaska and parts of Canada. Physical Description Grizzly bears can vary in color from blonde to black. In rare cases, their fur may be white. Their fur consists of coarse, protective hairs with shorter, softer hairs underneath to keep them warm. Their guard hairs have lighter tips, creating a “grizzled” look and leading to the nickname used for North American brown bears. They have a large, wide, dish-shaped head with a long snout. They have a defined shoulder hump composed of fat and muscle. This well-developed shoulder musculature aids in digging for food and for defense, as do the 2-4 inch claws. Grizzly bear size is dependent on several factors, including habitat, sex of the bear, and nutrition; weight ranges between 170 to more than 1300 pounds. They stand at about 3-4 feet tall at the shoulder while on all fours and 6-7 feet tall when standing upright. Reproduction Grizzly bears mate May through July, but embryonic implantation (delayed implantation) does not occur until December when the mother is about to hibernate. During mating, males may fight over females and guard them for 1-3 weeks. There can be one to three cubs born in late January or early February while the mother is still in the den, and they are born blind and weighing about one pound. The newborn cubs do not hibernate. They sleep next to their mother, nurse, and grow rapidly from their mother’s rich milk. Grizzly bear cubs remain with their mothers until they are 2-3 years old. Behavior Grizzly bears are active periodically throughout the day and night, resting during the heat of the day. They use their sharp claws to dig for food and to dig winter dens. Grizzly bears are not true hibernators (a drastic reduction in body temperature and metabolic rates). Grizzly bear hibernation can also be termed “denning”. During hibernation, grizzly bears don’t eat, drink, urinate, or defecate; they live off fat reserves from the spring and summer. They wake up occasionally during the winter, and may even leave their dens. Grizzly bears communicate by vocalizing and by scratching or rubbing on trees to mark territorial boundaries. They have an excellent sense of smell, allowing them to smell carrion more than 2 miles away. Food Habits Grizzly bears are opportunistic omnivores, eating anything they can find. This includes plants, roots, tubers, grasses, nuts, and berries, but they also hunt prey such as fish, insects, deer, and even moose. Occasionally, they have been observed hunting black bears. Brown bears also scavenge food, eating carcasses left by other predators. Being opportunistic feeders, garbage left unattended or in unsecured containers is an attractant to grizzly bears, which can lead to property damage and destruction of the bear for “problem behavior”. Conservation Status The conservation status of grizzly bears varies depending on the population and habitat. However, in the US, grizzly bears are listed as threatened in the lower 48, and thereby protected by the Endangered Species Act. It is estimated there are currently 1,000 brown bears in the lower 48 states. Habitat loss and alteration from logging, mining, and road construction, is a major factor in the decrease of grizzly bear populations. In addition to bears being hunted for fur and food, they are also killed out of fear, for coming too close to human populations, and in certain cultures, bear parts are believed to have medicinal properties, which leads to killing of individuals. Grizzly bears are vital to their ecosystem as seed dispersers and as a top predator. Since brown bears are such important parts of their ecosystem, conservation efforts for brown bears help other species in that ecosystem as well.

Grizzly Bears and Climate Change Grizzlies in Yellowstone feed on the high-fat seeds of the whitebark pine when preparing for their winter sleep. But many of these trees have been destroyed by the mountain pine beetle—an insect that has been able to move into this area due to a warming climate. When bears can’t find the food they need in the wild, they are more likely to wander into human habitats. You can help by reducing your use of fossil fuels like oil, gas, and coal. Burning these fossil fuels release excess carbon that acts like a blanket around the Earth, trapping in the Earth’s heat and contributing to a warmer climate.

Examples of community climate-change solutions:

 Start a neighborhood carpool  Join a community garden  Support local businesses that use renewable resources  Use renewable resources to power your home or business  Support renewable energy research