Brown bear

Name and taxonomy

Ursus is Latin for bear, and arktos is Greek for bear, so the scientific name says bear twice. Linnaeus gave that name in the 1758 edition of Systema Naturae. The old English word bruin comes from a Middle Dutch word for brown, through the fable of Reynard the Fox. American settlers of the 1800s called the bear Old Ephraim and Moccasin Joe. The name grizzly describes the grizzled coat of inland North American bears, with dark hairs tipped in cream.

Brown bear taxonomy is a tangle: scientists have named up to 90 subspecies over the years. In 2005 the scientific community recognised 15 living or recently extinct subspecies. DNA studies find only five to nine main lineages, and one of those is the polar bear. In North America, the coastal brown bear and the inland grizzly are two forms of the same subspecies, Ursus arctos horribilis. The Kodiak bears of Alaska have probably been isolated since the last ice age.

Evolution and relatives

The brown bear is one of eight living bears, and it belongs to the subfamily Ursinae with six of them. It is thought to descend from the Etruscan bear of Asia in the early Pliocene. Its line separated from the cave bears about 1.2 to 1.4 million years ago. The oldest brown bear fossils come from Asia and are 500,000 to 300,000 years old. Brown bears reached Europe about 250,000 years ago, then North Africa. In Britain they may have helped push the cave bear to extinction.

They crossed into North America from Siberia over the Beringia land bridge in several waves that followed the ice ages. The founding lineage of most North American bears dates to about 177,000 years ago. The polar bear is the brown bear's sister species, and the two still interbreed. DNA confirmed a wild grizzly-polar hybrid in the Canadian Arctic in 2006. Seven more have turned up since, all descended from one female polar bear. The bears of Alaska's Alexander Archipelago carry old polar bear DNA from a population stranded at the end of the Pleistocene.

Appearance

The brown bear varies more in size than any other bear. Inland grizzlies average about 180 kilograms for males and 135 kg for females. Coastal bears fed on salmon weigh about twice as much: males on the southern Alaskan coast average 389 kg. The tail is short, at 6 to 22 centimetres. A bear weighs least in spring after the winter fast. In late autumn it can carry up to 180 kg of extra fat.

The coat runs from cream through red and yellow-brown to almost black, and legs are often darker than the body. Indian bears can be reddish with silver tips, and Chinese bears wear a pale collar across the chest and shoulders. Winter fur grows thick and long, up to 11 to 12 cm at the shoulders in the north. A mane of longer hair lies along the back of the neck.

The brown bear is the only living bear with a shoulder hump, and the hump is pure muscle for digging. The front claws are longer than the back ones, at 5 to 6 cm straight and 7 to 10 cm round the curve. Those blunt claws and that weight mean an adult cannot climb a tree the way a black bear does. The skull is massive and concave in profile, and the jaws carry large canines with the lower pair strongly curved.

Habitat and range

No other bear uses so many kinds of country. Brown bears live from sea level to 5,000 metres in the Himalayas. They use tundra, every type of northern forest, alpine meadows and coasts. They prefer semi-open land with enough cover for a daytime rest. Once the species roamed the Great Plains, the Atlas Mountains of North Africa and most of Europe.

Russia holds about 130,000 bears, the United States about 32,500 and Canada around 25,000. Alaska alone has about 30,000, and the bears are slowly returning along the Rockies and the western plains of the lower 48 states. Europe had about 14,000 in 2010, split into ten separate populations from Spain to Russia. Romania has 5,000 to 6,000, the Pyrenees only 20 to 25, and central Italy's Marsican bears number about 50. In Asia the bear ranges from Turkey and Iran through central Asia and Siberia to China, Korea and the Japanese island of Hokkaido.

Bears in Alaska and western Canada are stable, but the populations of the Sierra Nevada, the southern Rockies and northern Mexico are gone. The Mexican grizzlies died out in the 1960s.

Diet and feeding

The brown bear eats a wider variety of food than any other bear. In spring it lives on winter-killed carrion, grass, sedges, shoots and moss. In summer and early autumn it turns to berries, nuts and fruit, and in a poor fruit year inland bears dig roots and bulbs. No other bear digs so well for tough food. Its long claws open the ground and its heavy jaws bite through roots. Insects matter too: bears in Yellowstone may eat 40,000 army cutworm moths in a day and take up to half their yearly energy from them.

On the Kamchatka peninsula and the Alaskan coast, bears live mostly on spawning salmon, and that rich food explains their huge size. They gather at waterfalls and snatch leaping fish from the air, or wade in and pin a fish with their claws. At the peak of the run a bear eats only the eggs and head and leaves the rest to foxes, eagles, ravens and gulls.

Most brown bears are clumsy hunters, and many chases of large prey end with the prey escaping. A few bears, taught by their mothers, hunt elk, moose, caribou, muskoxen and wild boar with confidence, and they target the young and the weak. A bear kills by pinning the animal and eating it alive. A blow of the forearm can break the back of a moose. Near people they raid crops, beehives, cattle and rubbish, and Yellowstone closed its open dump because bears came to link people with food.

Behaviour and social life

The brown bear lives alone for most of the year and meets others only to mate or at a rich food source. At a salmon river or a dump, bears form a hierarchy by age and size. Big adult males rank highest, but a mother with cubs is the most aggressive bear of all. A dominant bear faces its rival head on, shows its canines and stretches its neck, and the loser turns sideways, drops its head and sits.

Bears are not territorial, and several adults share the same ground without trouble. Home ranges are vast: in Yellowstone a female uses up to 281 square kilometres and a male up to 874. In the central Canadian Arctic, where food is scarce, a male may range over 8,171 square kilometres. Activity peaks in the morning and early evening, and bears that live near people become fully nocturnal. In autumn a bear may travel a very long way to reach a salmon stream or a berry crop.

From October to December a bear digs a den on a sheltered slope, under a rock or among tree roots. It lines the den with dry plants. Its body temperature drops only a few degrees, so this is a deep winter sleep rather than true hibernation, and the bear wakes easily.

Communication and senses

Smell is the bear's main sense, and it can follow the scent of a carcass for more than two miles. Hearing is about as good as a person's, and eyesight is relatively poor. Bears rub and scratch trees and other landmarks to leave scent that tells others who passed and whether a female is in season. A female in oestrus marks with urine, and the scent draws several males.

Bears have a rich set of faces. A relaxed open mouth with a curled lip invites play, while flattened ears and a closed mouth mean the bear feels threatened. A gaping jaw that shows the lower canines is a warning of attack. A tense bear huffs about twice a second, an alarmed bear woofs, and an aggressive bear growls. A charging bear's growl builds to a roar that carries 2 kilometres, and cubs bawl when they want their mother.

Reproduction and life cycle

Mating runs from mid-May to early July, and later further north. Both sexes take several partners. A male usually mates with two females in a few weeks, and a female may accept four or even eight males. Females mature at four to eight years, and males mate about a year later, once they can compete. A female comes into season only every three to four years, because she is busy with cubs in between.

The fertilised egg floats free in the womb for about six months and implants only when the female enters her winter den. If she has not stored enough fat, the embryo is reabsorbed and there are no cubs that year. The cubs are born about eight weeks after implantation, while the mother sleeps, so the whole pregnancy spans 180 to 266 days. A litter is usually one to three cubs, though six have been recorded. A newborn is blind, hairless and toothless and weighs 350 to 510 grams.

The cubs suckle in the den until spring, leave it at 7 to 9 kilograms, and follow their mother over long distances. They learn everything from her: what to eat, where to find it, how to fish and where to den. They stay with her for 1.5 to 4.5 years, on average about 2.5 in North America. The father plays no part, and a strange male may kill cubs to bring their mother back into season within two to four days. A wild bear lives 20 to 30 years, and the oldest known wild bear was nearly 37.

Predators and threats

An adult brown bear has no regular predator apart from the Siberian tiger and other bears. In the Russian Far East tigers killed bears 32 times between 1944 and 1959, mostly young animals or small females caught outside their dens. In the same period bears killed four tigresses and cubs. Wolves, cougars and other bears take cubs, and cubs flee up a tree when a strange male approaches. Between 13% and 44% of cubs die in their first year, most of them from hunger.

People kill far more bears than tigers do. Hunting, poaching, road and rail collisions, and the spread of farms and resorts all take a toll. A three-year survey in the Russian Far East found bear gall bladders being smuggled to Southeast Asia, though no medical value has ever been shown. Yearly mortality is about 10% in most protected areas. Bears carry flukes, ticks, tapeworms and lice, and may catch distemper from dogs and wolves.

Population and conservation

The IUCN lists the brown bear as Least Concern, with a world population of about 200,000. Of the eight living bears, only it and the American black bear escape a threatened listing. That headline hides many local disasters. Hunters wiped out the Atlas bear of North Africa in the 19th century. The grizzlies of California, Mexico and the Pacific Northwest followed by the mid 20th century. The lower 48 states held about 100,000 bears in the early 1900s and fewer than 1,000 today.

The Himalayan brown bear is Critically Endangered and keeps only 2% of its former range, because poachers kill it for body parts. The Syrian brown bear has gone from more than half of its range. Europe's 2000 action plan paid compensation for livestock losses, taught farmers safer practices and protected forest. Sweden's bears grew by 1.5% a year between the 1940s and the 1990s. In central Asia conservationists plan wildlife corridors to link populations that climate change is pulling apart.

Relationship with humans

People have hunted brown bears for at least 9,300 to 10,300 years. European bounty schemes in the 17th and 18th centuries pushed the bear close to extinction before protection came in the 1900s. Grizzlies received some US protection only in the 1920s, and Alaska still allows licensed hunting.

Most brown bears keep away from people and seldom charge without cause. A surprised bear or a mother with cubs is the danger. Mothers defending cubs cause 70% of the deaths from brown bears in North America. A 2019 study counted 664 attacks across North America and Eurasia in 15 years, with 568 injuries and 95 deaths. Bear spray stopped aggressive bears in 92% of studied cases, against 67% for guns.

More than 700 brown bears live in zoos, and the species has performed in circuses since Roman times. Dancing bears were trained by standing cubs on hot metal plates while a violin played, a cruelty that persists in places. Today bear watching earns money in Yellowstone and Alaska, and the shooting of Bear 148 by a trophy hunter in 2017 caused public outrage.

In culture and myth

The bear is among the oldest subjects of human art, with over 100 cave paintings from the Palaeolithic. Many Native American peoples hold the brown bear sacred. In Denaa tradition, hunters cut off all four paws of a dead bear so that its spirit could not escape. They waited before eating the meat. A bear claw necklace marked a brave and honoured person, and its rattle was thought to heal. In Haida tradition, the people descend from the marriage of a woman and a grizzly bear.

In ancient Greek tradition bears were seen as close to people, because they stand upright, and the goddess Artemis was linked to the bear. Several Siberian and Finno-Ugric peoples, and the Ainu of Japan, treated the bear as an ancestor or elder relative. They held bear feasts in its honour. Western fables paint the bear as slow, foolish and easily tricked. The real animal is not: bears have backtracked in snow to fool hunters.

The bear is the national animal of Finland and the unofficial symbol of Russia. It appears on the arms of Madrid, reaching into a strawberry tree. It is also on the arms of Bern, a name popularly tied to the German word for bear. Children meet the brown bear in Goldilocks, in Snow White and Rose Red, and in the Scottish tale The Brown Bear of Norway.