BROWN BEARS: CHARACTERISTICS, HISTORY, SIZE

BROWN BEARS

brown bear in Slovenia

Brown bears (Ursus arctos) are the most widely distributed of all the world’s bears. Their range includes much of the Northern Hemisphere, including North America, Russia, Europe and Asia as far east as Japan. They found as far south as Spain and Iran and used to found in Mexico and Morocco but are extinct there now. Brown bears are found in a variety of habitats but they prefer environments that feature of mix of river valleys, mountain forests and open meadows. The species and its subspecies are known by many names, including grizzly, Kodiak, Kamchatka, Tibetan and Gobi bear.

Brown bears rank with polar bears and Siberian tigers as the world's largest land carnivores. The largest known brown bears weigh around 850 kilograms (1,800 pounds) and stand almost four meters (12 feet) tall on their hind legs. There are around 70,000 brown bears and grizzly bears in North America. There are also large numbers of them in Russia and they are found elsewhere in Asia and Europe. For some reason there are lot of them in Romania. The rare Tibetan blue bear is among the brown bear subspecies.

Losing territory to human expansion and hunted for their fur, brown bears now cover just two percent of their former habitat, numbering some 200,000. Half are in Russia, 30,000 in North America and 17,000 in Europe. The genetic diversity of brown bears has been extensively studied and appears to be geographically structured into five main clades based upon analysis of the mtDNA. The average life span for a wild brown bear is about 20 years, although many bears typically live longer than this. The oldest wild brown bears known lived for about 35 years. most brown bears die in their first few years of life. In captivity, brown bears have been known to live up to 50 years. Because of their size and aggressiveness towards threats, brown bears are not often preyed upon. Humans of course hunt them. Cubs are sometimes killed by other bears or by mountain lions or wolves, although this is very rare. [Source: Tanya Dewey and Liz Ballenger, Animal Diversity Web (ADW) |=|]

Brown Bear Habitat and Range

Brown bears once ranged throughout northern Europe, northern Asia and North America. They ranged as far south as the Atlas mountains of Morocco and Algeria, and Mexico but are extinct on these places now. Still thet have a wide distribution are found in fairly health numbers in parts of Russia, Hokkaido in Japan. Alaska, western Canada and the U.S. states of Montana, Wyoming and Idaho. They are found in smallers numbers and fragmented populations in western Europe, Central Asia, the Middle East and the Himalayan region. In the United States they have been extirpated from the Sierra Nevada and southern Rockies. Northern Mexican populations were extirpated in the 1960's.

brown bear range

Brown bears generally live in temperate or cold areas areas with a climate similar to the northern U.S. and Europe, Alaska, Canada and Russia in tundra, taiga, forests and coastal areas but are also found in some arid regions and hot climates such as Gobi desert, arid Central Asia and the Middle East.

Brown bears occupy a variety of habitats, from desert edges to high mountain forests and ice fields. In North America they prefer open areas such as tundra, alpine meadows, and coastlines. Historically, they were common on the Great Plains prior to the arrival of European settlers. In the Russian Far East, brown bears occurs primarily in forests, while European populations are restricted mainly to mountain woodlands. The main habitat requirement for Brown bears are some area with dense cover in which it can shelter by day. [Source: Tanya Dewey and Liz Ballenger, Animal Diversity Web (ADW) |=|]

Brown Bear Evolution and History

Brown bears have been around millions of years, sharing Siberia, Eurasia and North America with mammoths, mastodons, giant beavers and saber tooth tigers. Polar bears evolved from brown bears. The two species are similar enough that today they have breed in zoos and produced fertile offspring.

Brown bears are believed to have evolved from Etruscan bears (Ursus etruscus) in Asia during the early Pliocene Period (5.4 million to 2.4 million years ago). DNA analysis indicated suggests that the brown bear lineage diverged from the cave bear species-complex approximately 1.2–1.4 million years ago. The oldest known brown bear fossils are from Asia and date to about 500,000 to 300,000 years ago. Brown bears appear to have entered Europe 250,000 years ago and North Africa not long afterwards. Brown bear remains from the Pleistocene Period (2.58 million years to 11,700 years ago). are common in the British Isles; its has been theorized that they may have contributed to the extinction of cave bears (Ursus spelaeus) there. [Source: Wikipedia]

Etruscan bear

Brown bears first emigrated to North America from Eurasia via Beringia (including the Bering Strait land bridge) during a period of intense glaciation 191,000 to 130,000 years ago. Genetic evidence suggests that several brown bear populations migrated into North America in conjunction with Pleistocene glacial cycles. The founding population of most North American brown bears arrived first, with the genetic lineage developing around 177,000 ago. Genetic divergences suggest that brown bears first migrated south 92,000 to 83,000 during the opening of the ice-free corridor. After a local extinction in Beringia about 33,000 years ago two new but closely related lineages repopulated Alaska and northern Canada from Eurasia after the Last Glacial Maximum about 25,000 years ago.

Extinct California grizzly bears (Ursus arctos californicus) bears weren't the giant "hypercarnivores" they have been made out to be. Research published in early 2024 found. They were similar in size to modern grizzlies and they were mostly vegetarian, and only occasionally ate livestock after European colonizers and American settlers began farming in California. They rarely, if ever, weighed more than 900 kilograms (2,000 pounds). [Source: Live Science, January 16, 2024]

Brown Bear Characteristics

Brown bears range in weight from 80 to 600 kilograms (176.2 to 1321.6 pounds) and reach lengths of 2.8 meters (9.2 feet) from head to rump. Their tails are 6.5 to 21 centimeters (2.6 to 4 inches) long. They stand 90 to 150 centimeters (3 to 5.2 feet) tall at the shoulder and can tower at an intimidating height of 2.5 meters (eight feet) when standing upright on their hind legs. Large individuals can extend themselves almost four meters (12 feet) tall on their hind legs with their forelegs raised. Brown bears in Katmai in southern Alaska are some of the largest bears in the world. They can stand 0.9 to 1.5 meters (3 to 5 feet) at the shoulder and measure 2.1 to 3 meters (7 to 10 feet) in length. [Source: Animal Diversity Web, U.S. National Park Service]

Terry Domico and Mark Newman wrote in “Bears of the World”: “The brown bear is stout and rather chunky in shape, with a large hump of fat and muscle over the shoulder and very long claws. It has a wide, massive head that some people describe as being somewhat ‘dish faced" in appearance. That big head is equipped with extremely powerful jaws. I once saw a big male, trapped in a leg snare set by researchers, take out its frustration on some neighboring trees. In one bite he bit completely through a 4-inch (10-centimeter) -diameter pine, snapping it off. It also chewed through several 6- and 8-inch (15- and 20-centimeter) -diameter trees. One stump looked as though it had been dynamited. When we slammed the sharp end of a geologist's pick into the trunk of one of those trees, it only penetrated about 1.5 inches (3.8 centimeters) into the wood." [Source: “Bears of the World” by Terry Domico and Mark Newman, 1988]

skeleton of an extinct California brown bear

Brown bears are usually dark brown but they also can be gray, tan, black, cream or reddish. Brown bears can be distinguished from brown-colored black bears by their larger size, dished-in facial profile, maned hump on the shoulders and long front claws. Some say the breath of brown bear is more like wind.

Brown bears have extremely flexible forepaws. Their paws can be up to 21 centimeters (8.3 inches) wide and 36 centimeters (14 inches) long. Brown bears have long claws that can inflict severe wounds but are primarily usd to dig up roots and tubers. Their teeth are similar to those of other bears and reflect their ability to eat both mean and plants. Distance between the canines is from six to eight centimeters.

Brown bears have evolved large hump muscles, unique among bears, The shoulder hump on a brown bear is a mass of muscle used to assist them while digging for roots, squirrels, etc. It allows the bear to apply tremendous pressure to the ground to dig. [Source:U.S. National Park Service, September 30, 2016]

Brown Bear Movement and Swimming

Brown bears wander large distances—up to 80 kilometers (50 miles)—each day. Males cover perhaps twice to three times as much ground as sows. Brown bears move with a slow, lumbering walk, although they capable of moving very quickly and can easily catch a black bear. Brown bears are mainly terrestrial, although they can often be found swimming or preying upon fish in the water. Adults are unable to climb trees but young can. [Source: Tanya Dewey and Liz Ballenger, Animal Diversity Web (ADW) |=|]

The hulking, loose-skinned shape of brown bears hides a remarkable agility that allows them to sprint up to 35 miles per hour (54 kph) to catch salmon in their teeth. Brown bears outrun a horse at short distances and outswim an Olympian. Brown bears usually moves along at an ambling pace or fast walk with their head down. When alerted they lift their heads up and move at a trots, or at top speed in full gallop. They have also been observed ascending and descending precipitous canyon walls. Their huge size prevents brown bears from climbing trees as black bears do.

front paws of a brown bear

From their muscular shoulders to their huge paws, brown bears are built mainly for digging. They tunnel underground to build dens and to search for roots, rodents and other things to eat. The grizzly's pronounced shoulder hump, used in digging, is one of the easiest ways tell it apart from a black bear. [Source: Dino Grandoni, Washington Post, January 21, 2023]

Brown bears are able to swim across large, fast moving rivers. Brown bears are extremely strong and have good endurance; they can kill a cow with one blow, and drag a dead elk uphill. There is floating pontoon bridge over the Brooks River in Katmai where brown bears fish for salmon. Bears can swim between the pontoons that keep the bridge floating. Not all bears choose to swim under the bridge. Every year, there are bears that seem to prefer walking around the bridge instead of underneath it, but most bears that frequently fish near the bridge will swim underneath it. [Source: U.S. National Park Service, September 30, 2016]

Difference Between Male and Female Brown Bears

Sexual Dimorphism (differences between males and females) is present: Adult males are larger and more compactly built than females. . On average, adult males are eight to 10 percent larger than females. [Source: Tanya Dewey and Liz Ballenger, Animal Diversity Web (ADW) |=|]

Most adult male Brown bears in Katmai in southern Alaska weigh 272 to 408 kilograms (600 to 900 pounds) in mid-summer. By October and November, large adult males can weigh well over 454 kilograms (1000 pounds). Adult females average about a third less in weight than adult males. [Source: U.S. National Park Service, September 30, 2016]

How do you tell a male bear from a female bear? First, look for genitalia. It is usually easy to see on adult males, but can be difficult to spot on females. If you are still unsure, then watch for bears to urinate. Bears of all ages can be sexed by watching them pee. Male bears will urinate straight down between their hind legs. Females will urinate backward between their hind legs. Urination pattern is especially useful when you are trying to determine the sex of cubs. Additionally, the presence of cubs with an adult bear is an absolute indicator that you are looking at a female. Male bears play no role in raising young. [Source: U.S. National Park Service, September 30, 2016]

Bite-Force of Brown Bear Enough to Crush a Bowling Ball

brown bear skull

The bite force of a brown bear is considered strong enough to crush a bowling ball. Grizzly bears, in particular, have a bite force of over 1200 PSI (pounds per square inch), according to various sources. This is significantly stronger than a human's bite force of 162 PSI. A bite force of 1200 PSI. is strong enough to crush a bowling ball, which is typically made of a durable, heavy plastic. Other animals with strong bite forces include the nile crocodile (5000 PSI), hippopotamus (1800 PSI), and polar bear (1200 PSI). [Source: Google AI]

According to David et. Al.: "The disparity in body size between carnivorous bears and their preferred prey suggests that bears are able to rely on muscular strength to process kills, rather than depending on well-developed craniodental adaptations that enhance muscle leverage and dental function that are typical of canids that hunt large prey. Instead, carnivorous ursids are more similar to omnivorous canids, which also outweigh their typical prey, though to a less dramatic degree. Whereas carnivorous bears may be as much as 100 times heavier than their prey, coyotes and red foxes typically take prey as large as a third of their own body mass ." [Source: Davis JL, Santana SE, Dumont ER, Grosse I (2010) Predicting bite force in mammals: two-dimensional versus three-dimensional lever models. Journal of Experimental Biology 213: 1844–1851]

"Therefore, researchers have turned to models to estimate bite forces based on approximations of the structure of the skull and the physiology of the muscles that adduct the jaws. Bite force estimates are often used in comparative studies, where they are correlated with ecological tasks , stress distribution in the skull, and morphological variables such as bite point, gape, skull size or muscle mass."

"Thomason's method of predicting bite force is the model that is most commonly applied to mammals. The values of bite force predicted by this method are based on a static 2-D lever mechanics model in which muscle forces are determined from an assumed muscle stress and an estimated muscle area. These predicted values are consistently lower than in vivo measurements . It is not clear why this is the case, although one possibility is that the method by which muscle areas are determined is a source of error."

Image Sources: Wikimedia Commons

Text Sources: Animal Diversity Web animaldiversity.org ; National Geographic, Live Science, Natural History magazine, CNTO (China National Tourism Administration) David Attenborough books, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Discover magazine, The New Yorker, Time, BBC, CNN, Reuters, Associated Press, AFP, Lonely Planet Guides, Wikipedia, The Guardian, Top Secret Animal Attack Files website and various books and other publications.

Last updated May 2025