Only the polar bear rivals the brown bear’s land size
Ursus arctos ranges Eurasia and North America as one of Earth’s largest land carnivorans, challenged in bulk mainly by its polar cousin. Forests up to about 5,000 meters host this omnivore, still IUCN least concern despite local wipeouts across a shrunken map.
Despite its fearsome reputation, the brown bear gets about 90% of its food from plants. When it does hunt, prey ranges from insects and rodents up to moose and muskoxen. Size varies more than in any other living bear: adults weigh roughly 80 to 600 kilograms, measure 1 to 2.8 metres from nose to rump, and males are typically at least 30% heavier than females. Weight also swings with the seasons, bottoming out in spring after the winter fast. Coat colour is equally unreliable, from cream to near black, with reddish silver-tipped bears in India and collared two-tone animals in China.
Linnaeus named it Ursus arctos in 1758, doubling up the Latin and Greek words for bear. The English nickname bruin comes via Caxton's translation of the fable of Reynard the Fox, and 19th-century Americans called it Old Ephraim. Classifying it has been called formidable and confusing: as many as 90 subspecies have been proposed. In North America the coastal brown bear and the inland grizzly are usually both placed in one subspecies.
The species likely descends from the Etruscan bear of early Pliocene Asia and split from the cave bear lineage around 1.2 to 1.4 million years ago. It crossed into North America over Beringia during an ice age, and fossils from Ontario, Ohio and Labrador show it once lived far east of its historic range. Bears on Alaska's Alexander Archipelago still carry traces of polar bear ancestry, and wild grizzly–polar bear hybrids were confirmed in the Canadian Arctic in 2006.
Around 110,000 brown bears were estimated in 2017, yet hunting in the 19th and 20th centuries wiped out populations such as North Africa's Atlas bear and California's bears. Kept in zoos since antiquity, it features widely in art and myth.
Source: Brown bear
