The glacier bear (''Ursus americanus emmonsii''), sometimes referred to as the "blue bear", is a subspecies of

American black bear The American black bear (''Ursus americanus''), also called simply a black bear or sometimes a baribal, is a medium-sized bear endemic to North America. It is the continent's smallest and most widely distributed bear species. American black bear ...

with silver-blue or gray hair

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

from

Southeast Alaska Southeast Alaska, colloquially referred to as the Alaska(n) Panhandle, is the southeastern portion of the U.S. state of Alaska, bordered to the east and north by the northern half of the Canadian province of British Columbia (and a small part ...

, to the extreme northwestern tip of

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

, and to the extreme southwest of the

Yukon Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...

. The

Tlingit The Tlingit ( or ; also spelled Tlinkit) are indigenous peoples of the Pacific Northwest Coast of North America. Their language is the Tlingit language (natively , pronounced ),

name for the glacier bear is a reference to their size, elusiveness, and ability to visually blend into snowfields: "sik noon", which means "a bear that disappears". Little scientific knowledge exists of their total extent and the cause of their unique coloration. Most other black bears in southeast Alaska are listed under the subspecies ''Ursus americanus pugnax''.MacDonald, S.O. and Cook, J.A. (2007
Mammals and amphibians of Southeast Alaska
The Museum of Southwestern Biology, The University of New Mexico, Albuquerque, NM 87131-0001.Schoen, J and Peacock, L. (2007) "Black Bear" in J Schoen and E Dovichin (eds.
The coastal forest and mountains ecoregion of southeastern Alaska and the Tongass National Forest
Audubon Alaska and The Nature Conservancy, 715 L Street, Anchorage, Alaska The USDA Forest Service lists'' U. a. emmonsii'' as one of several subspecies of black bears, although no evidence supports the subspecies designation other than hair coloration.

Unique features

The chief feature distinguishing the glacier bear from other black bears is its

pelage Fur is a thick growth of hair that covers the skin of mammals. It consists of a combination of oily #Guard hair, guard hair on top and thick #Down hair, underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as ...

(hair coloration), which ranges from silvery blue to gray. The subspecies was reported by

William Healey Dall William Healey Dall (August 21, 1845 – March 27, 1927) was an American naturalist, a prominent malacologist, and one of the earliest scientific explorers of interior Alaska. He described many mollusks of the Pacific Northwest of America, and w ...

in 1895. This variation can be seen on individual bears that are often lighter on their backs and shoulders, with their legs and belly being much darker or even black.

Habitat and range

The glacier bear's habitat ranges have been reported to be the Alaskan coastal areas between Cross Sound and Cape St. Elias and from

Prince William Sound Prince William Sound (Sugpiaq: ''Suungaaciq'') is a sound of the Gulf of Alaska on the south coast of the U.S. state of Alaska. It is located on the east side of the Kenai Peninsula. Its largest port is Valdez, at the southern terminus of the Tr ...

Glacier Bay Glacier Bay Basin in southeastern Alaska, in the United States, encompasses the Glacier Bay and surrounding mountains and glaciers, which was first proclaimed a U.S. National Monument on February 25, 1925, and which was later, on December 2, 1980 ...

in southeast Alaska, with a few sightings as far east as

Juneau, Alaska The City and Borough of Juneau, more commonly known simply as Juneau ( ; tli, Dzánti K'ihéeni ), is the capital city of the state of Alaska. Located in the Gastineau Channel and the Alaskan panhandle, it is a unified municipality and the se ...

, and the

Taku River The Taku River (Lingít: ''T'aaḵu Héeni'') is a river running from British Columbia, Canada, to the northwestern coast of North America, at Juneau, Alaska. The river basin spreads across . The Taku is a very productive salmon river and its dra ...

that flows between British Columbia and Alaska. This region includes

Glacier Bay National Park Glacier Bay National Park and Preserve is an American national park located in Southeast Alaska west of Juneau. President Calvin Coolidge proclaimed the area around Glacier Bay a national monument under the Antiquities Act on February 26, 1925. C ...

and portions of

Tongass National Forest The Tongass National Forest () in Southeast Alaska is the largest U.S. National Forest at . Most of its area is temperate rain forest and is remote enough to be home to many species of endangered and rare flora and fauna. The Tongass, which i ...

, a

temperate rainforest Temperate rainforests are coniferous or broadleaf forests that occur in the temperate zone and receive heavy rain. Temperate rain forests occur in oceanic moist regions around the world: the Pacific temperate rain forests of North American Paci ...

preserve. Glacier bears have also been reported in the extreme northwestern tip of British Columbia and to the extreme southwest of the Yukon. Few studies document the subspecies' range in association with other black bears. See for instance Hall's 1981 ''The Mammals of North America''. Glacier bears share most of the characteristics of black bears such as their habitat preferences, food sources, size, and reproductive cycles. They prefer forest with thick

understory In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but abov ...

and landscapes with abundant vegetation, but can be found in urban populated areas. The glacier bear habitat is dependent upon food source availability, and they move between forest, meadows, streams, and mountains in search of food and shelter. Black bears in general are very capable climbers and can use trees as a place of protection and refuge. Glacier bears move into their dens in early winter, which can be an overturned tree, a rock ledge, or a cave.

Diet

Glacier bears, like all other black bears, are

omnivore An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutr ...

s, with their diets varying depending on the food source available during the season and the location. Their diet includes young shoots and roots in early spring. During the summer in Alaska, the glacier bear eats the abundant Pacific salmon spawning in the streams. In some areas, moose and deer are a food source for black bears. During the fall, the bears eat the starchy roots of ground cones and the variety of berries found in Alaska such as blueberries, salmonberries, raspberries, and cranberries.

Reproduction

Breeding habits are much like any other black bear. The glacier bear female normally has her first litter by 3–5 years of age. This breeding period takes place in June through July. Gestation lasts 235 days and cubs are born in January to early February.Powell, Roger A., Zimmerman, John Wayne and Seaman, David Erran (1997) ''Ecology and behaviour of North American black bears: home ranges, habitat, and social organization''. Vol. 4. Springer, . Because of the increasing range of all subspecies of black bears since the last glacier maximum, interbreeding is taking place. It is thus possible to see a black-colored bear give birth to a bear with the glacier bears'

and vice versa.

Research

Very little is known about this rare color variation, so some potential threats could become an issue for the glacier bear. Some of these threats are

overharvesting Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term app ...

and gene swamping. Currently, no population projections are made due to the lack of genetic understanding. With the interbreeding capabilities of other black bears with different pelage, determining the future distinctive color variation and population density may become even more complicated. Also, speculation exists that the glacier bear had its origins in

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

s between black bears and grizzlies.Bear facts
/ref>

Unique features

Habitat and range

Diet

Reproduction

Research

References

Further reading