Subspecies of brown bear
Formerly or currently considered subspecies or populations of brown bears have been listed as follows:
List
| Subspecies/population | Image | Distribution | Description/comments |
| Ursus arctos horribilis – Grizzly bear / North American brown bear | Most of Alaska, the Yukon, the Northwest Territories, British Columbia, western Alberta, northern Idaho, western Montana, and northwestern Wyoming. | The grizzly bear is identified by a medium to dark brown coat with gray or blond "grizzled" tips on the fur, which contrast with the black base. Highly variable in size, based largely on environmental conditions. It is also highly adaptable: it can live in montane pine forests, temperate rainforest, semi-arid scrubland, tundra and shortgrass prairie. | |
| †Ursus arctos californicus – California grizzly bear | California, mainly in the Sierra Nevada Mountains and some areas of coastal California. | The last known California grizzly bear was shot in California in 1922. Museum specimens illustrate that this population was golden-blonde overall, typically without the contrasting black fur base of true grizzly bears. It also appeared to have been considerably larger, with a broader muzzle than true grizzly bears. | |
| Ursus arctos dalli – Dall Island brown bear | Dall Island, Alaska. | Poorly described; possibly merely a coastal variation of other North American brown bears, but any such alliance is genetically ambiguous. | |
| Ursus arctos gyas – Alaska Peninsula brown bear | Coastal Alaska from the Aleutian Islands as far west as Unimak, the Alaska Peninsula to the Kenai Peninsula. | Considered by some biologists to be the same subspecies as U. a. middendorffi. Based on the known size of adult males, if it is a true subspecies, it may match or exceed the Kodiak bear in size. | |
| Ursus arctos middendorffi – Kodiak bear | Kodiak, Afognak and Shuyak Islands, arguably includes other coastal Alaskan forms, which occur in most of the coasts of the western and southern parts of the state. | This is the largest distinct subspecies of the brown bear, though the coastal-living members of other brown bear subspecies potentially rival it in size. It is medium-hued, typically not as dark as most forms from eastern Asia, but distinctly darker than grizzly bears. | |
| Ursus arctos nelsoni – †Mexican grizzly bear | The smallest North American brown bear, formerly from northern Mexico, including Chihuahua, Coahuila and Sonora, and the southwestern United States, including the southern regions of Arizona, New Mexico and Texas | This bear is believed to have been hunted to extinction due to its interference with cattle ranching in both the United States and Mexico. Scarce by the 1930s, the last recorded sighting was in 1962. Distinct in its ability to survive arid conditions, it could live in both montane pine forests of Mexico and canyonlands adjacent to the Sonoran Desert. | |
| Ursus arctos sitkensis – Sitka brown bear | Admiralty Island, Baranof Island and Chichagof Island, the "ABC Islands" of Alaska. | Appearing to be more closely related to the polar bear than to other brown bears, although it is on average the most dark-colored population in North America, with similar body size to grizzly bears from interior Alaska. This subspecies is called "clade II" by Waits and others and is part of the former subspecies identified as U. a. sitkensis by Hall and as U. a. dalli by Kurtén. | |
| Ursus arctos stikeenensis – Stickeen brown bear | Northwestern British Columbia from the Stikine River to the Skeena River. | Variously recognized as a distinct subspecies or as belonging to the subspecies U. a. horribilis. Larger than most other grizzly bear populations, with males approaching the great bears of coastal Alaska in size. | |
| †Ursus arctos ungavaesis – Ungava brown bear | Northern Quebec and Labrador | Historical reports of brown bears in Quebec were typically dismissed by modern biologists. In 1975, however, anthropologist Steven Cox discovered a brown bear skull in Labrador, confirming that the population did once exist. |
Ecotypes or regional populations
Brown bear size, most often measured in body mass, is highly variable and is correlated to extent of food access. Therefore, bears whose range in areas with access to openings, cover, and moisture or water are on average larger, whereas those bears that range into enclosed forested areas or arid, sparsely vegetated regions, both of which tend to be suboptimal foraging habitat for brown bears, average smaller. The brown bear in northern Europe, Yellowstone National Park or interior Alaska seasonally weigh on average between, from mean low adult female weights in spring to male bear mean high weights in fall. Brown bears from the Yukon Delta, interior British Columbia, Jasper National Park and southern Europe can weigh from on average. These mass variations represent only two widespread subspecies, the grizzly bear in North America and the Eurasian brown bear in Europe. Due to the lack of genetic variation within subspecies, the environmental conditions in a given area likely plays the largest part in such weight variations.The grizzly is especially variable in size, as grizzlies from the largest populations, i.e. interior Alaska, with the heaviest weights recorded in Nelchina, Alaska, nearly three times heavier in males than the smallest grizzlies from Alberta, Canada's Jasper National Park. Between the sexes, the grizzlies of Nelchina average around, whereas the Jasper grizzlies averaged about. The enclosed taiga habitat of Jasper presumably is sub-optimal foraging habitat for grizzlies, requiring them to range widely and feed sparsely, thus reducing body weights and putting bears at risk of starvation, while in surfaces areas in the tundra and prairie are apparently ideal for feeding. Even elsewhere in Alberta, weights averaging more than twice those of Jasper grizzlies have been recorded. A gradual diminishment in body size is noted in grizzly bears from the sub-Arctic zone, from the Brooks Range to the Mackenzie Mountains, presumably because food becomes much sparser in such regions, although perhaps the most northerly recorded grizzly bears ever, in the Northwest Territories, was a large and healthy male weighing, more than twice as much as an average male weighs near the Arctic Circle. Data from Eurasia similarly indicates a diminished body mass in sub-Arctic brown bears, based on the weights of bears from northern Finland and Yakutia.
Head-and-body length in grizzly bears averages from while in Eurasian brown bears it similarly averages from. Adult shoulder height averaged in Yellowstone and a median of in Slovakia. Standing on its hindlegs, a posture only assumed occasionally, typically-sized brown bears can reportedly range from in standing height. Exceptionally large inland specimens have been reported in several parts of North America, Europe, Russia and even Hokkaido. The largest recorded grizzlies from Yellowstone and Washington state both weighed approximately and eastern European bears have been weighed in Slovakia and Bulgaria of up to, about double the average weight for male bears in these regions. Among the grizzly and Eurasian brown bear subspecies, the largest reportedly shot from each being and, respectively. The latter bear, from western Russia, reportedly measured just under in head-and-body length.
of Hokkaido, a relatively small-bodied population, in the snow
In Eurasia, the size of bears roughly increases from the west to the east, with the largest bears there native to eastern Russia. Even in the nominate subspecies, size increases in the eastern limits, with mature male bears in Arkhangelsk Oblast and Bashkortostan commonly exceeding. Other bears of intermediate size may occur in inland populations of Russia. Much like the grizzly and Eurasian brown bear, populations of the Ussuri brown bear and the East Siberian brown bear may vary widely in size. In some cases, the big adult males of these populations may have matched the Kodiak bear in size. East Siberian brown bears from outside the sub-Arctic and mainland Ussuri brown bears average about the same size as the largest-bodied populations of grizzly bears, i.e. those of similar latitude in Alaska, and have been credited with weights ranging from throughout the seasons. On the other hand, the Ussuri brown bears found in the insular population of Hokkaido are usually quite small, usually weighing less than, exactly half the weight reported for male Ussuri brown bears from Khabarovsk Krai. This is due presumably to the enclosed mixed forest habitat of Hokkaido. A similarly diminished size has been reported in East Siberian brown bears from Yakutia, as even adult males average around, thus about 40% less than the average weight of male bears of this subtype from central Siberia and the Chukchi Peninsula.
In linear measurements and mean body mass, several subspecies may vie for the title of smallest subtype, although thus far, their reported body masses broadly overlaps with those of the smaller-bodied populations of Eurasian brown and grizzly bears. Leopold described the now-extinct Mexican grizzly bear that, according to Rausch, as the smallest subtype of grizzly bear in North America, although the exact parameters of its body size are not known today. Bears of the Syrian subspecies will reportedly weigh around in adulthood. The Himalayan brown bear is another rival for the smallest subspecies; in Pakistan, this subtype averages about in females and in males. Himalayan brown bear females were cited with an average head-and-body length of merely. Brown bears of the compact Gobi Desert population, which is not usually listed as a distinct subspecies in recent decades, weigh around between the sexes, so they are similar in weight to bears from the Himalayas and even heavier than grizzlies from Jasper National Park. However, the Gobi bear has been reported to measure as small as in head-and-body length, which, if accurate, would make them the smallest known brown bear in linear dimensions. These smallest brown bear subtypes are characteristically found in "barren-ground" type habitats, i.e. sub-desert in bears from the Syrian subspecies and the Gobi subtype and arid alpine meadow in Himalayan brown bears.
s and polar bears to be marine mammals, the Kodiak bear is the largest of the living land-based mammalian predators.
The largest subspecies are the Kodiak bear and the questionably-distinct peninsular giant bear or coastal brown bear. Also the extinct California grizzly bear was rather large. Once mature, the typical female Kodiak bear can range in body mass from and from sexual maturity onward, males range from. According to the Guinness Book of World Records the average male Kodiak bear is in total length and has a shoulder height of. When averaged between their spring low and fall high weights from both localities, males from Kodiak island and coastal Alaska weighed from with a mean body mass of while the same figures in females were with a mean body mass of. By the time they reach or exceed eight to nine years of age, male Kodiak bears tend to be much larger than newly mature six-year-old males, potentially tripling their average weight within three years' time, and can expect to average between. The reported mean adult body masses for both sexes of the polar bear are very similar to the peninsular giant and Kodiak bears. Due to their roughly corresponding body sizes, the two subtypes and the species can both legitimately be considered the largest living member of the bear family Ursidae and the largest extant terrestrial carnivores. The largest widely accepted size for a wild Kodiak bear, as well as for a brown bear, was for a bear killed in English Bay on Kodiak Island in fall 1894 as several measurements were made of this bear, including a body mass of, and a hind foot and a voucher skull were examined and verified by the Guinness Book of World Records. Claims have been made of larger brown bears, but these appear to be poorly documented and unverified and some, even if recited by reputable authors, may be dubious hunters' claims.
The largest variety of brown bear from Eurasia is the Kamchatkan brown bear. In the Kamchatkan brown bears from past decades, old males have been known to reach a body mass of by fall, putting the subtype well within Kodiak bear sizes and leading it to be considered the largest of the extant Russian subtypes. However, a diminishment in body size of U. a. berigianus has been noted, mostly likely in correlation with overhunting. In the 1960s and 1970s, most adult Kamchatkan brown bears weighed merely between ; however, mean weights of mature male bears have been reported as averaging in 2005.