Wildlife
Brown Bear (Ursus arctos):
 Alaskans typically refer to coastal bears as browns and interior bears as grizzlies. Brown bears tend to be one third larger than grizzlies and one half larger than black bears. Brown bears are considered the largest living land carnivore. Though polar bears can be larger, they are not considered to be land dwelling. Brown bear sizes vary depending on location, time of year, age and gender. Most male brown bears range between 500 - 900 lbs., with mature females weighing approximately half that of males. Color also varies greatly, from black with silver tipped hair to blonde. Males tend to be darker than females and cubs often sport a white collar during their first summer.
Brown bears have a varied diet ranging from grasses in spring, fish in the summer, and berries during the fall. Meat is not always the major component of the bears' diet, but they will eat whatever they can find or catch, including marmots, porcupines, squirrels, mice, moose, and caribou. While they hunt and catch many small animals, much of the large game in a brown bear's diet is acquired through scavenging dead animals or chasing other predators away from their kills. Brown bears have no predators other than human hunters.
Breeding occurs May through July and cubs are born in January and February. As brown bears exhibit delayed implantation, newborn cubs weigh only 8 to 10 ounces. Litter size varies from one to four, with twins being the most common. Most females nurse their young for two summers and then the cubs usually set off on their own during the third summer.
 Brown bears are typically dormant during the winter months, but this dormancy is not the same as a true hibernation. Denning times can vary depending on location, snow levels, and temperature. Togiak Refuge is participating in the Kuskokwim Mountain Brown Bear study, in which the study bears tend to enter their dens in November and emerge in March or April. While denning, the bears' metabolism and temperature are lowered and their need for food and water eliminated. Bears in colder climates will remain in their dens longer, and males typically emerge before females.
Resources:
Burt, William H. and Richard P. Grossenheider. 1980. Peterson field guide to mammals. Houghton Mifflin Company. Boston Massachusetts.
Alaska Geographic Society. 1996. Mammals of Alaska: a comprehensive field guide from the publishers of Alaska geographic. The Alaska Geographic Society. Anchorage Alaska.
For more information, visit the Alaska Department of Fish and Game's wildlife notebook pages.
Last updated: July 24, 2008
|
