Difference between revisions of "Brown bear" - New World Encyclopedia

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{{Taxobox
 
{{Taxobox
 
| name = Brown bear
 
| name = Brown bear
 
| fossil range = Late Pleistocene - Recent   
 
| fossil range = Late Pleistocene - Recent   
| status = LR/lc | status_system = IUCN2.3
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| status = LC
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| status_system = iucn2.3
 
| status_ref =<ref>B. N. McLellan, C. Servheen, and D. Huber, [http://www.iucnredlist.org/details/41688 "''Ursus arctos'',"], ''2008 IUCN Red List of Threatened Species'' (IUCN 2008). Retrieved December 28, 2008. </ref>
 
| status_ref =<ref>B. N. McLellan, C. Servheen, and D. Huber, [http://www.iucnredlist.org/details/41688 "''Ursus arctos'',"], ''2008 IUCN Red List of Threatened Species'' (IUCN 2008). Retrieved December 28, 2008. </ref>
 
| image = Grizzlybear55.jpg
 
| image = Grizzlybear55.jpg
| image_width = 300px
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| image_width = 240px
| image_caption = [[Grizzly Bear]] (''U. arctos horribilis'')
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| image_caption = [[Grizzly bear]] ''(U. arctos horribilis)''  
 
| regnum = [[Animal]]ia
 
| regnum = [[Animal]]ia
 
| phylum = [[Chordata]]  
 
| phylum = [[Chordata]]  
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| range_map_caption = ''Ursus arctos'' range map.
 
| range_map_caption = ''Ursus arctos'' range map.
 
}}
 
}}
'''Brown bear''' is the common name for  
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'''Brown bear''' is the common name for a large [[bear]], '''''Ursus arctos,''''' ranging in color from a common brown to yellowish or black [[fur]] and having a noticeable shoulder hump and a concave face. The most widely distributed member of the bear family, Ursidae, it is found in much of northern [[Eurasia]] and [[North America]]. Other well-known common names for various subspecies or populations include '''grizzly bear,''' '''Kodiak bear,''' '''Alaskan brown bear,''' '''Russian brown bear,''' '''Asiatic brown bear,''' '''Himalayan snow bear,''' and '''European brown bear.''' The brown bear sometimes is referred to as the "bruin."
  
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The brown bear is a massive animal, weighing between 100 and 700 kilograms (220-1,500 [[pound (mass)|pounds]]) and its larger populations, such as the Kodiak bear, match the [[polar bear]] as the largest extant land carnivores. While the brown bear's range has shrunk, and it has faced local extinctions, it remains listed as a [[least concern]] species with a total population of approximately 200,000. Its principal range countries are [[Russia]], the [[United States]] (especially [[Alaska]]), [[Canada]], and [[Finland]].
  
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The species primarily feeds on [[vegetable]] matter, including [[roots]] and [[berry|berries]], as well as [[fungi]]. [[Fish]] are a primary source of meat, and it will also kill small mammals on land. Larger mammals, such as [[deer]], are taken only occasionally. Adult brown bears can match wolf packs and large felines, often driving them off their kills. As a seed disperser and predator, it plays an important role in the [[ecosystem]].
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While encounters with the brown bear in the wild can be dangerous for humans, these remarkable animals also add greatly to the wonder of [[nature]] and are prized sightings on [[ecotourism|ecotours]]. They also are popular trophies in sports hunting. Once sought for their meat and hides, they are less commonly used for such purposes. Extraction of bear [[bile]], used in [[Traditional Chinese Medicine]] (TCM), is reported to involve a great deal of cruelty for the animals (see [[Bile#Commercial uses|bile]]).
  
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==Description==
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[[Image:Brown bear (Ursus arctos arctos) running.jpg|200 px|thumb|left|A [[Eurasian brown bear]] running.]]
  
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Brown bears have heads that are large and round with a concave facial profile, a characteristic used to distinguish them from other bears. Their snout protrudes from this concave or "hollow" face (Grzimek et al. 2004). They also have a large hump of [[muscle]] over their shoulders (Grzimek et al. 2004), which helps to distinguish them from such species as the black bear ''(Ursus americanus)'', which lacks this characteristic hump (Cameron 2005). Their tail is short, 10 to 13 centimeters (4 to 5 inches) long (Brown 1993).
  
(''Ursus arctos'') is a large [[bear]] distributed across much of northern [[Eurasia]] and [[North America]]. It weighs between 100–700 kg (220-1,500 [[pound (mass)|pounds]]) and its larger populations such as the [[Kodiak bear]] match the [[Polar bear]] as the largest extant land carnivores. While the brown bear's range has shrunk, and it has faced local extinctions, it remains listed as a [[least concern]] species with a total population of approximately 200,000. Its principal range countries are [[Russia]], the [[United States]] (especially [[Alaska]]), [[Canada]], and [[Finland]] where it is the national animal.
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The forearms of brown bears end in massive paws with claws up to 15 centimeters (6 inches) in length, which are mainly used for digging. Brown bear claws are not retractable, and have relatively blunt points. Like all bears, brown bears are [[plantigrade]]s and can stand up on their hind legs for extended periods of time.  
  
Other well-known common names for various subspecies or populations include
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Brown bears have [[fur]] in shades of brown, black, tan or blond, or a combination of those colors. The longer outer guard hairs of the brown bear are often tipped with white or silver, giving a "grizzled" appearance.
  
The species primarily feeds on [[vegetable]] matter, including [[roots]], and [[fungi]]. [[Fish]] are a primary source of meat, and it will also kill small mammals on land. Larger mammals, such as [[deer]], are taken only occasionally. Adult brown bears can match wolf packs and large felines, often driving them off their kills.  
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Brown bears are large and very powerful, and can break the backs and necks of large prey. Males are 38 to 50 percent larger than females (Brown 1993). The normal range of physical dimensions for a brown bear is a head-and-body length of 1.7 to 2.8 meters (5.6-9.2 feet) and a shoulder height 90 to 150 centimeters (35-60 inches). The smallest subspecies is the [[Eurasian brown bear]] with mature females weighing as little as 90 kilograms (200 pounds) (Wood 1983). Barely larger, [grizzly bear]]s from the [[Yukon]] region (which are a third smaller than most grizzlies) can weigh as little as 100 kilograms (220 lb) in the spring (BF), and mature females of the [[Syrian brown bear]] weigh as little as 150 kilograms (331 pounds). The largest subspecies of the brown bear are the [[Kodiak bear]], [[Siberian brown bear]], and the bears from coastal [[Russia]] and [[Alaska]]. It is not unusual for large male Kodiak bears to stand over 3 meters (10 feet) while on their hind legs and to weigh about 680 kilograms (1,500 lb). The largest wild Kodiak bear on record weighed over 1,100 kilograms (2,500 pounds) (Brown 1993).  
  
It is sometimes referred to as the '''''bruin''''', from Middle English, based on the name of the bear in ''History of Reynard the Fox'', translated by [[William Caxton]], from Middle Dutch ''bruun'' or ''bruyn''<ref>American Heritage Dictionary of the English Language: Fourth Edition.  2000.</ref>.
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Size seems related to food availability, with subspecies distinctions being more related to nutrition rather than geographical location (Macdonald 1984). Bears raised in zoos are often heavier than wild bears because of regular feeding and limited movement. In zoos, bears may weigh up to 900 kilograms (2,000 pounds).
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==Distribution and habitat==
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[[Image:Brown bear seaguls.jpg|left|thumb|300px|Brown bear at [[Brooks Falls]].]]
  
==Taxonomy==
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The most widely distributed [[Ursidae|ursid]] (McLellan et al. 2008), the brown bear has a global distribution, with populations in North America, Europe, northern Asia, and Japan (Grzimek et al. 2004). It occupies about 5 million square kilometers of North America, 800,000 square kilometers of Europe (excluding Russia), and much of northern Asia (McLellan et al. 2008).
  
There is little agreement on classification of brown bears. Some systems have proposed as many as 90 sub-species while recent DNA analysis has identified as few as five clades.<ref>{{cite web |url= http://www.bearinfo.org/YESFedRegister.pdf |title= Endangered and Threatened Wildlife and Plants; Designating the Greater Yellowstone Ecosystem Population of Grizzly Bears as a Distinct Population Segment; Removing the Yellowstone Distinct Population Segment of Grizzly Bears From the Federal List of Endangered and Threatened Wildlife |accessmonthday= August 1 |accessyear= 2006 |author= U.S. Fish and Wildlife Service |date= 2006-11-17 |publisher= Federal Register / Vol. 70, No. 221  |pages=69854-69884|format=PDF}}</ref> DNA analysis has recently revealed that the identified subspecies of brown bears, both Eurasian and North American, are genetically quite homogeneous, and that their genetic [[phylogeography]] does not correspond to their traditional taxonomy.<ref name="Waits">{{cite web |url= http://www.cnrhome.uidaho.edu/documents/Waits%20et%20al%201998%20cb.pdf&pid=78496&doc=1|title= Mitochondrial DNA Phylogeography of the North American Brown Bear and Implications for Conservation |accessmonthday= August 1 |accessyear= 2006 |author= Lisette P. Waits, Sandra L. Talbot, R.H. Ward and G. F. Shields |year= 1998 |month= April |publisher= Conservation Biology|pages= 408-417}}</ref> The subspecies of brown bears have been listed as follows: one of which (called clade I by Waits, et al., part of the subspecies identified as ''U. a. sitkensis'', by Hall and ''U. a. dalli'' by Kurtén) appears to be more closely related to the [[polar bear]] than to other brown bears.<ref name="Waits" />
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There are about 200,000 brown bears in the world. The largest populations are in Russia, with 120,000, the United States with 32,500, and Canada with 21,750. Ninety-five percent of the brown bear population in the United States is in [[Alaska]], though in the western United States they are repopulating slowly but steadily along the [[Rockies]] and plains. In Europe, there are 14,000 brown bears in ten separate fragmented populations, from [[Spain]] in the west, to [[Russia]] in the east, and from [[Scandinavia]] in the north to [[Romania]], [[Bulgaria]], and [[Greece]] (with about 200 animals) in the south. They are extinct in the [[British Isles]], extremely threatened in [[France]] and Spain, and in trouble over most of Central Europe. The brown bear is [[Finland]]'s national animal. The Carpathian brown bear population is the largest in Europe outside Russia, estimated at 4,500 to 5,000 bears.
* ''Ursus arctos arctos'' &ndash; [[Eurasian Brown Bear]]
 
* ''Ursus arctos ognevi'' &ndash; East from Kolyma River
 
* ''Ursus arctos beringianus'' &ndash; [[Kamchatka Brown Bear]]; Kamchatka Peninsula and Paramushir Island
 
* ''Ursus arctos californicus &ndash; California golden bear (extinct)
 
* ''Ursus arctos crowtheri'' &ndash; [[Atlas Bear]] (extinct)
 
* ''Ursus arctos gobiensis'' &ndash; Gobi bear; Mongolia
 
* ''Ursus arctos horribilis'' &ndash; [[Grizzly Bear]]; Canada and United States
 
* ''Ursus arctos isabellinus'' &ndash; [[Himalayan Brown Bear]]; Nepal, Pakistan and Northern India
 
* ''Ursus arctos formicarius'' &ndash; Carpathian Bear;
 
[[Image:polarbrown-1.jpg|200px|thumb|Polar/Brown Bear Hybrid, Rothschild Museum, Tring]]
 
* ''Ursus arctos lasiotus'' &ndash; [[Amur brown bear]] ( or "Ussuri brown bear", "black grizzly" or "horse bear"), [[Russia]]: Southern [[Kuril Islands]], [[Sakhalin]], [[Maritime Territory]], and the [[Ussuri]]/[[Amur]] river region south of the [[Stanovoy Range]]. [[People's Republic of China|China]]: Northeastern [[Heilongjiang]]. [[Japan]]: [[Hokkaidō]]
 
* ''Ursus arctos marsicanus'' &ndash; [[Marsican Brown Bear]]; Central Italy (critically endangered)
 
* ''Ursus arctos meridionalis'' &ndash; Northern Caucasus
 
* ''Ursus arctos middendorffi'' &ndash; [[Kodiak Bear]]; Kodiak, Afognak, Shuyak Islands (Alaska)
 
* ''Ursus arctos nelsoni'' &ndash; [[Mexican Grizzly Bear]]; (extinct)
 
* ''Ursus arctos collaris'' &ndash; [[Siberian Brown Bear]]; Siberia (except for the habitat of the Kamchatka and Amur brown bears.) Also in northern Mongolia, far northern Xinjiang, and extreme eastern Kazakhstan.
 
* ''Ursus arctos pruinosus'' &ndash; Tibetan [[Blue Bear]]; Western China
 
* ''Ursus arctos syriacus'' &ndash; [[Syrian Brown Bear]]; Middle East
 
* ''Ursus arctos yesoensis'' &ndash; Hokkaido Brown Bear; Japan
 
* ''Ursus arctos piscator'' &ndash; Bergman's Bear (extinct?)
 
  
===Hybrids===
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Brown bears were once native to the [[Atlas Mountains]] in [[Africa]], and may have existed as late as the mid-1800s in Algeria and Morocco and as late as 1500s in the Sinai of Egypt, but are not extinct in these areas (McLellan et al. 2008). They also were once in Mexico, but were extirpated there and in a large portion of the southwestern United States during the twentieth century (McLellan et al. 2008). Although many hold on to the belief that some brown bears still may be present in Mexico and the Atlas Mountains of Morocco, both are almost certainly extinct. The last known Mexican brown bear was shot in 1960. Very small numbers remain in Iraq and Nepal, but they have apparently been eliminated from Syria and possibly Bhutan (McLellan et al. 2008).
A [[grizzly–polar bear hybrid]] is a rare [[ursid hybrid]] resulting from a union of a brown bear and a polar bear. It has occurred both in captivity and in the wild. In 2006, the occurrence of this hybrid in nature was confirmed by testing the [[DNA]] of a strange-looking bear that had been shot in the [[Canada|Canadian]] [[arctic]].<ref name="msn">{{cite news  |url = http://msnbc.msn.com/id/12738644/?GT1=8199 |title = Wild find: Half grizzly, half polar bear: Hunter bags what expert 'never thought would happen' in wild |publisher = MSNBC.MSN.com |date = [[May 11]], [[2006]] |accessdate = 2006-05-14}}</ref> Previously, the hybrid had been produced in zoos and was considered a "[[Cryptozoology|cryptid]]" (a hypothesized animal for which there is no scientific proof of existence in the wild). <!--Depending on who is the father or the mother, hybrids are named Pizzly Bear (male Polar bear with female Grizzly) or '''Grolar bear''' (male Grizzly with female Polar bear).<ref name = naming>[http://messybeast.com/genetics/hybrid-names.htm Naming Conventions] A semi-scientific reference for hybrid naming conventions, with specific examples of big-cat hybrids.</ref> —>
 
  
==Description==
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Brown bears live in [[Alaska]], east through the [[Yukon]] and [[Northwest Territories]], south through [[British Columbia]] and through the western half of [[Alberta]]. Small populations exist in the Greater Yellowstone ecosystem of northwest Wyoming (with about 600 animals), the Northern Continental Divide ecosystem of northwest Montana (with about 400-500 animals), the Cabinet-Yaak ecosystem of northwest Montana and northeast Idaho (with about 30-40 animals), the Selkirk ecosystem of northeast Washington and northwest Idaho (with about 40-50 animals), and the North Cascades ecosystem of north-central Washington (with about 5-10 animals). These five ecosystems combine for a total of roughly 1,200 wild grizzlies still persisting in the contiguous United States. Unfortunately, these populations are isolated from each other, inhibiting any genetic flow to occur between [[ecosystem]]s. This poses one of the greatest threats to the future survival of the grizzly bear in the contiguous United States.
[[Image:Brown bear (Ursus arctos arctos) running.jpg|200 px|thumb|left|A [[Eurasian Brown Bear]] running. Brown bears can be fast runners despite their size, capable of speeds of up to 56 km/h (35 mph){{Fact|date=November 2008}}]]
 
Brown bears have furry coats in shades of blonde, brown, black, or a combination of those colors. The longer outer guard hairs of the brown bear are often tipped with white or silver, giving a "grizzled" appearance. Their tail is 4-5 inches (10-13 cm) long.<ref name="Bearalmanac">{{cite book | author = Brown, Gary | title = Great Bear Almanac | year = 1996 | pages = pp.340 | isbn = 1558214747}}</ref> Like all bears, brown bears are [[plantigrade]]s and can stand up on their hind legs for extended periods of time. Brown bears have a large hump of [[muscle]] over their shoulders which distinguishes them from other species.<ref>[http://www.mountainnature.com/wildlife/Bears/BearID.htm Learn to Identify Black Bears and Grizzly (Brown) Bears<!-- Bot generated title —>]</ref> Brown bears are very powerful, and can break the backs and necks of large prey. The forearms end in massive paws with claws up to 15 cm (6 inches) in length which are mainly used for digging. Brown bear claws are not retractable, and have relatively blunt points. Their heads are large and round with a [[wiktionary:Concave|concave]] facial profile, a characteristic used to distinguish them from other bears. Males are 38-50% larger than females.<ref name="Bearalmanac" /> The normal range of physical dimensions for a brown bear is a head-and-body length of 1.7 to 2.8 m (5.6 to 9.2 feet) and a shoulder height 90 to 150 cm (35 to 60 inches). The smallest subspecies is the [[Eurasian Brown Bear]] with mature females weighing as little as 90 kg (200 lb).<ref>Wood, The Guinness Book of Animal Facts and Feats. Sterling Pub Co Inc (1983), ISBN 978-0851122359</ref> Barely larger, [[Grizzly Bear]]s from the [[Yukon]] region (which are a third smaller than most grizzlies) can weigh as little as 100 kg (220 lb) in the spring<ref>[http://www.yesnet.yk.ca/projects/bears/facts/e/grizzly.html The Bear Facts - Types of bears in the Yukon<!-- Bot generated title —>]</ref> and the [[Syrian Brown Bear]], with mature females weighing as little as 150 kg (331 lb). The largest subspecies of the brown bear are the [[Kodiak bear]], [[Siberian Brown Bear]], and the bears from coastal [[Russia]] and [[Alaska]]. It is not unusual for large male Kodiak Bears to stand over 3 m (10 feet) while on their hind legs and to weigh about 680 kg (1,500 lb). The largest wild Kodiak bear on record weighed over 1,100 kilograms (2,500 pounds).<ref name="Bearalmanac" /> Bears raised in zoos are often heavier than wild bears because of regular feeding and limited movement. In zoos, bears may weigh up to 900 kilograms (2,000 pounds), one example being "Goliath" from New Jersey's [[Space Farms Zoo and Museum]]. Size seems related to food availability, with subspecies distinctions being more related to nutrition rather than geographical location.<ref name="Encyclopedia">{{cite book | author = Macdonald, David | title = The Encyclopedia of Mammals: 1| year = 1984 | pages = pp.446 | isbn = 0-04-500028-x}}</ref>
 
In spite of their size, some brown bears have been clocked at speeds in excess of 56 km/h (35 mph).{{Fact|date=November 2008}}
 
  
==Distribution and habitat==
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The population of brown bears in the [[Pyrenees]] mountain range between [[France]] and [[Spain]] is so low, estimated at fourteen to eighteen with a shortage of females, that bears, mostly female, from [[Slovenia]] were released in the spring of 2006 to alleviate the imbalance and preserve the species' presence in the area, despite protests from French farmers.
[[Image:Brown bear seaguls.jpg|left|thumb|300px|Brown Bear at [[Brooks Falls]]]]
 
There are about 200,000 brown bears in the world. The largest populations are in Russia, with 120,000, the United States with 32,500, and Canada with 21,750. 95% of the brown bear population in the United States is in Alaska, though in the West they are repopulating slowly but steadily along the [[Rockies]] and plains. Although many hold on to the belief that some brown bears may be present in Mexico and the Atlas Mountains of Morocco, both are almost certainly extinct.  The last Mexican  brown bear was shot in 1960. In Europe, there are 14,000 brown bears in ten separate fragmented populations, from [[Spain]] in the west, to [[Russia]] in the east, and from [[Scandinavia]] in the north to [[Romania]], [[Bulgaria]] and [[Greece]] (with about 200 animals) in the south. They are extinct in the [[British Isles]], extremely threatened in [[France]] and Spain, and in trouble over most of Central Europe. The brown bear is [[Finland]]'s national animal. The Carpathian brown bear population is the largest in Europe outside Russia, estimated at 4,500 to 5,000 bears.
 
  
Brown bears were once native to [[Asia]], the [[Atlas Mountains]] in [[Africa]], [[Europe]] and [[North America]],<ref>{{cite web |url=http://news.bbc.co.uk/2/hi/science/nature/4003325.stm |title=http://news.bbc.co.uk/2/hi/science/nature/4003325.stm |accessdate= |format= |work= }}</ref> but are now [[extinct]] in some areas and their populations have greatly decreased in other areas. They prefer semi-open country, usually in mountainous areas.  
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In [[Arctic]] areas, the potential habitat of the brown bear is increasing. The seeming warming of that region has allowed the species to move farther and farther north into what was once exclusively the domain of the [[polar bear]]. In non-Arctic areas, habitat loss is blamed as the leading cause of endangerment, followed by hunting.
  
Brown bears live in [[Alaska]], east through the [[Yukon]] and [[Northwest Territories]], south through [[British Columbia]] and through the western half of [[Alberta]]. Small populations exist in the Greater Yellowstone Ecosystem of northwest Wyoming (with about 600 animals), the Northern Continental Divide Ecosystem of northwest Montana (with about 400-500 animals), the Cabinet-Yaak Ecosystem of northwest Montana and northeast Idaho (with about 30-40 animals), the Selkirk Ecosystem of northeast Washington and northwest Idaho (with about 40-50 animals), and the North Cascades Ecosystem of north-central Washington (with about 5-10 animals).  These five ecosystems combine for a total of roughly 1,200 wild grizzlies still persisting in the contiguous United States.  Unfortunately, these populations are isolated from each other, inhibiting any genetic flow to occur between ecosystems.  This poses one of the greatest threats to the future survival of the grizzly bear in the contiguous United States.
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North American brown bears seem to prefer open landscapes, whereas in Eurasia they inhabit mostly dense forests. It is thought that the Eurasian bears that colonized America were [[tundra]] adapted, something indicated by brown bears in the [[Chukotka Peninsula]] on the Asian side of Bering Strait, which are the only Asian brown bears to live year-round in lowland tundra like their American cousins (RHA 2007).  
  
The population of brown bears in the [[Pyrenees]] mountain range between [[France]] and [[Spain]] is so low, estimated at fourteen to eighteen with a shortage of females, that bears, mostly female, from [[Slovenia]] were released in the spring of 2006 to alleviate the imbalance and preserve the species' presence in the area, despite protests from French farmers.
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==Behavior==
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The brown bear is primarily solitary animals, although they may gather in large numbers at major food sources and form social hierarchies based on age and size (Dewey and Ballenger 2002; Grzimek et al. 2004). They may be active at any time, but primarily forage in the morning and at dusk, and rest during the day (Dewey and Ballenger 2002).  
  
In [[Arctic]] areas, the potential habitat of the brown bear is increasing. The warming of that region has allowed the species to move farther and farther north into what was once exclusively the domain of the [[polar bear]]. In non-Arctic areas, habitat loss is blamed as the leading cause of endangerment, followed by hunting.
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In the summer, the brown bear may put on substantial reserves of fat (up to 180 kilograms or 400 pounds of [[fat]] in larger populations), on which it relies to make it through winter, when it becomes very lethargic. Although they are not full [[Hibernation|hibernators]], and can be woken easily, both sexes like to [[matrnity den|den]] in a protected spot such as a [[cave]], crevice, or hollow log during the winter months.  
  
North American brown bears seem to prefer open landscapes, whereas in Eurasia they inhabit mostly dense forests. It is thought that the Eurasian bears which colonized America were tundra adapted, something indicated by brown bears in the [[Chukotka Peninsula]] on the Asian side of Bering Strait, which are the only Asian brown bears to live year-round in lowland tundra like their American cousins.<ref>[http://www.russianbearhunt.com/ Brown Bear Hunting in Russia<!-- Bot generated title —>]</ref>
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===Reproduction===
  
==Brown bear in prehistory==
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The mating season takes place from late May through early July. Being serially [[monogamous]], brown bears will remain with the same mate from several days to a couple of weeks. Females become sexually mature between the age of 5 and 7 years, while males will usually not mate until a few years later when they are large and strong enough to successfully compete with other males for mating rights.
===North America===
 
The brown bear has existed in North America since at least the most recent ice age, though it is thought that the larger, taller, and stronger [[Arctodus simus|giant short-faced bear]] or bulldog bear was the dominant carnivore at the time. The giant short-faced bear was a tall, thin animal adapted to eating large mammals, whereas the grizzly or brown bear has teeth appropriate for its [[omnivorous]] diet.
 
The brown bear also shared North America with the [[American lion]] and [[Smilodon]], carnivorous competitors. The modern grizzly can eat plants, insects, carrion, and small and large animals. The American lion, Smilodon, and giant short-faced bear had a more limited range of food, making them vulnerable to starvation as the supply of available large mammals decreased, possibly due to hunting by humans.
 
  
The time of the ''Arctodus'' extinction is about the same as that of the [[long-horned Bison]] and other [[megafauna]]. Both of these animals were replaced by Eurasian immigrants, specifically the Brown Bear and [[American Bison]].  Since this was also about the same time as the [[Clovis]] tool kit hunting culture appeared in North America, with culturally advanced humans entering the Americas from Asia, the implication is that the brown bear was better adapted to human competition than the megafauna, presumably due to a long term coexistence in the Old World with people.  
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Through the process of [[delayed implantation]], a female's fertilized egg will divide and float free within the uterus for six months. During winter dormancy, the fetus will attach itself to the uterine wall and the cubs will be born after an eight-week period while the mother sleeps. Should the mother not gain enough weight to survive through the winter, the embryo will not implant and be reabsorbed into the body.  
  
The extinction of ice-age herbivorous megafauna resulted in the extinction of the sabertooth, American lion, and giant short-faced bear, leaving the brown bear as the major large predator in North America, with the [[gray wolf]], the [[jaguar]] in the south, the [[American black bear]], and [[cougar]] also competing for large prey. The origin of human presence in America is widely accepted to have occurred across the [[Bering Land Bridge]] with the largest known immigration being that of the [[Paleo Indians]] at about the last ice age, bringing with them the [[Clovis point]] and advanced hunting techniques (see: [[Models of migration to the New World#Land bridge theory|Migration to the New World]]). When the last ice age ended about 10,000 years ago, brown bears from farther south in North America slowly expanded their range northward and back up into Alaska. Today there are three [[genetically]] distinct grizzly bear [[clade]]s in North America: the Alaskan-Yukon Grizzly, the Alberta-[[Saskatchewan]] lineage, and those found in the Colorado-Washington-Idaho-Montana-Wyoming area.
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The average litter number is between one and four, with two being the most common number, though there have been cases of bears with five cubs, though it is not unusual for females to adopt strange cubs. The size of a litter depends on a number of factors, such as the age of the mother, geographic location, and food supply. Older females tend to give birth to larger litters.  
  
===Eurasia===
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The cubs are born blind, toothless, hairless and weigh less than 1 pound at birth. They feed on their mother’s milk until spring and as late as early summer depending on climate conditions. The cubs, which will weigh from 15 to 20 pounds at this time, will have developed enough to follow her and begin to forage for solid food.
In Europe, the brown bear shared its habitat with other predators such as the [[Cave lion]], [[Cave hyena]] and the larger, closely related [[Cave bear]], which the brown bear ultimately outlasted. The cave bear was hunted by [[Neanderthal]]s who may have had a religion relating to this bear, the [[Cave Bear Cult]], but the Neanderthal population was too small for their consumption of cave bear to result in the species' extinction, and the cave bear outlasted the Neanderthals by 18,000 years, becoming extinct about 10,000 years ago. The cave bear and brown bear diets were similar, and the two species probably lived in the same area at the same time. Why the cave bear died out is not known.
 
The Caledonian bear was said to be so fierce that it was favoured by the Romans who used them in their amphitheatres.
 
  
==Behavior==
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Cubs will remain with their mother from two to four years, during which time they will learn survival techniques such as which foods have the highest nutritional values and where to attain them, how to hunt, how to fish, how to defend themselves and where to den. The cubs learn by following and imitating their mother’s actions during the period they are with her (SOTB).
The brown bear is primarily [[nocturnal]] and, in the summer, puts on up to 180 kg (400 pounds) of [[fat]], on which it relies to make it through winter, when it becomes very lethargic. Although they are not full [[Hibernation|hibernators]], and can be woken easily, both sexes like to [[matrnity den|den]] in a protected spot such as a [[cave]], crevice, or hollow log during the winter months. Brown bear are mostly solitary, although they may gather in large numbers at major food sources and form social hierarchies based on age and size.<ref>[http://animaldiversity.ummz.umich.edu/site/accounts/information/Ursus_arctos.html Animal Diversity Web - ''Ursus arctos'']</ref>
 
  
===Reproduction===
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Brown bears engage in [[infanticide (zoology)|infanticide]] (Bellemain et al. 2006). An adult male bear may kill the cubs of another bear either to make the female sexually receptive or simply for consumption. Cubs will flee up a tree when they sight a strange male bear and the mother will defend them even though the male may be twice her size.
[[Image:Bear and cubs fapas.jpg|thumb|200px|right|Female [[Cantabrian brown bear]] and cubs. With kind permission of [http://www.fapas.es Fapas] (Conservation NGO - Foundation for the Protection of Wild Animals)
 
]]
 
The mating season takes place from late May through early July. Being serially [[monogamous]], brown bears will remain with the same mate from several days to a couple of weeks. Females become sexually mature between the age of 5 and 7 years, while males will usually not mate until a few years later when they are large and strong enough to successfully compete with other males for mating rights.
 
Through the process of [[delayed implantation]], a female's fertilized egg will divide and float free within the uterus for six months. During winter dormancy, the fetus will attach itself to the uterine wall and the cubs will be born after an eight-week period while the mother sleeps. Should the mother not gain enough weight to survive through the winter, the embryo will not implant and be reabsorbed into the body. The average litter number is between one and four, with two being the most common number, though there have been cases of bears with five cubs, though it is not unusual for females to adopt strange cubs. The size of a litter depends on a number of factors such as the age of the mother, geographic location and food supply. Older females tend to give birth to larger litters. The cubs are blind, toothless, hairless and weigh less than 1 pound at birth. They feed on their mother’s milk until spring and as late as early summer depending on climate conditions. The cubs, which will weigh from 15 to 20 pounds at this time, will have developed enough to follow her and begin to forage for solid food.
 
Cubs will remain with their mother from two to four years, during which time they will learn survival techniques such as which foods have the highest nutritional values and where to attain them, how to hunt, how to fish, how to defend themselves and where to den. The cubs learn by following and imitating their mother’s actions during the period they are with her.<ref>[http://www.shadowofthebear.com/reproduction.html Brown Bear Reproduction<!-- Bot generated title —>]</ref> Brown bears practice [[infanticide (zoology)|infanticide]].<ref>[http://www.ingentaconnect.com/content/bsc/eth/2006/00000112/00000003/art00004;jsessionid=6580enj8ip2kk.alice?format=print Mating Strategies in Relation to Sexually Selected Infanticide in a Non-Social Carnivore: the Brown Bear]</ref> An adult male bear may kill the cubs of another bear either to make the female sexually receptive or simply for consumption. Cubs will flee up a tree when they sight a strange male bear and the mother will defend them even though the male may be twice her size.
 
  
 
===Dietary habits===
 
===Dietary habits===
[[Image:Brown Bear Feeding on Salmon.jpg|thumb|150px|Brown bear feeding on [[salmon]]]]
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[[Image:Brown Bear Feeding on Salmon.jpg|thumb|150px|Brown bear feeding on [[salmon]].]]
They are [[omnivore]]s and feed on a variety of plant products, including berries, [[root]]s, and [[shoot|sprout]]s, [[fungi]] as well as meat products such as [[fish]], [[insect]]s, and small [[mammal]]s. Despite their reputation, most brown bears are not particularly carnivorous as they derive up to 90% of their dietary [[food energy]] from vegetable matter.<ref>[http://www.dced.state.ak.us/oed/student_info/learn/bearwatching.htm Alaska Office of Economic Development<!-- Bot generated title —>]</ref> Their jaw structure has evolved to fit their dietary habits. Their diet varies enormously throughout their differing ranges. For example, bears in Yellowstone eat an enormous number of [[moth]]s during the summer, sometimes as many as 40,000 in a day, and may derive up to half of their annual food energy from these insects.<ref>[http://www.yellowstonepark.com/MoreToKnow/ShowNewsDetails.aspx?newsid=163 Yellowstone Grizzly Bears Eat 40,000 Moths a Day In August<!-- Bot generated title —>]</ref> Locally, in areas of Russia and Alaska, brown bears feed mostly on spawning salmon, and the nutrition and abundance of this food accounts for the enormous size of the bears from these areas. Brown bears also occasionally prey on [[deer]], [[elk]], [[moose]], [[caribou]], and [[bison]]. When brown bears attack these animals, they tend to choose the young ones since they are much easier to catch. When hunting, the brown bear uses its sharp canine teeth for neck-biting its prey. On rare occasions, bears kill by hitting their prey with their powerful forearms which can break the necks and backs of large prey, such as bison. They also feed on [[carrion]] and will use their size to intimidate other predators such as [[wolf|wolves]], [[cougars]], [[black bears]] from their kills.
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Brown bears are [[omnivore]]s and feed on a variety of plant products, including [[berry|berries]], [[root]]s, and [[shoot|sprout]]s, as well as [[fungi]] and meat products such as [[fish]], [[insect]]s, and small [[mammal]]s. Despite their reputation, most brown bears are not particularly carnivorous as they typically derive up to 90 percent of their dietary [[food energy]] from vegetable matter (DCED). Their jaw structure has evolved to fit their dietary habits.  
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The diet of brown bearns varies enormously throughout their differing ranges. For example, bears in Yellowstone National Park during eat an enormous number of [[moth]]s during the summer, sometimes as many as 40,000 in a day in August, and may derive up to half of their annual food energy from these insects (Reed 2006). Locally, in areas of Russia and Alaska, brown bears feed mostly on spawning [[salmon]], and the nutrition and abundance of this food accounts for the enormous size of the bears from these areas. Brown bears also occasionally prey on [[deer]], [[elk]], [[moose]], [[caribou]], and [[bison]]. When brown bears attack these animals, they tend to choose the young ones since they are much easier to catch. When hunting, the brown bear uses its sharp canine teeth for neck-biting its prey. On rare occasions, bears kill by hitting their prey with their powerful forearms, which can break the necks and backs of large prey, such as bison. They also feed on [[carrion]] and will use their size to intimidate other predators such as [[wolf|wolves]], [[cougars]], and [[black bears]] from their kills.
  
 
===Interspecific predatory relationships===
 
===Interspecific predatory relationships===
Brown bears will often use their large size to intimidate [[wolf|wolves]] from their kills. In Yellowstone National Park, brown bears pirate wolf kills so often that Yellowstone’s Wolf Project Director Doug Smith wrote: "It’s not a matter of if the bears will come calling after a kill, but when." Though conflict over carcasses is common, the two predators will, on rare occasions, tolerate each other on the same kill. Given the opportunity, both species will prey on each other's cubs.<ref>http://www.wolf.org/wolves/news/iwmag/2006/spring/personalencounter.pdf</ref>
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Brown bears will often use their large size to intimidate [[wolf|wolves]] from their kills. Though conflict over carcasses is common, the two predators will, on rare occasions, tolerate each other on the same kill. Given the opportunity, both species will prey on each other's cubs.
[[Image:Canis lupus pack fighting Ursus arctos horribilis (illustration).jpg|thumb|250 px|Reconstruction of a brown bear confronting a wolf pack by Adolph Murie (1944)]]
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[[Image:Canis lupus pack fighting Ursus arctos horribilis (illustration).jpg|thumb|250 px|Reconstruction of a brown bear confronting a wolf pack by Adolph Murie (1944).]]
Adult bears are generally immune from predatory attacks from anything other than another bear. Some bears emerging from hibernation will seek out tigers in order to steal their kills. <ref name="Tigersnow">{{cite book | last = Matthiessen | first = Peter | coauthors = Hornocker, Maurice | year= 2001 | title = Tigers In The Snow | publisher = North Point Press | isbn = 0865475962 }}</ref> However, in the [[Russian Far East]] brown bears, along with smaller [[Asiatic black bear]]s constitute 5-8% of the diet of [[Siberian tiger]]s.<ref name="der-tiger">Vratislav Mazak: ''Der Tiger''. Nachdruck der 3. Auflage von 1983. Westarp Wissenschaften Hohenwarsleben, 2004 ISBN 3 894327596http</ref> In particular, the brown bear's input is estimated as 1-1,5%. However, tigers prefer to contest brown bear sows (for instance, in all cases recorded by the Wildlife Conservation Society under the “Siberian Tiger Project” since 1992). <ref name="Seryodkin_PhD">{{cite web |url= http://uml.wl.dvgu.ru/rscv.php?id=74 |title= The ecology, behavior, management and conservation status of brown bears in Sikhote-Alin (in Russian) |author= Seryodkin, Ivan |year=2006 |publisher= Far Eastern National University, Vladivostok, Russia|pages=pp.1-252}}</ref> For the tiger, even bears of the same size are a force to be reckoned with when confronted head on. There are known 12 incidents, when Siberien tigers were killed and eaten by brown bears <ref>{{cite book | author = Seryodkin, I. V., J. M. Goodrich, A. V. Kostyrya, B. O. Schleyer, E. N. Smirnov, L. L. Kerley, and D. G. Miquelle| date= 2005 | title =Relationship between tigers, brown bears, and Himalayan black bears. Pages 156-163 in Miquelle, D. G., E. N. Smirnov, and J. M. Goodrich, editors, Tigers of Sikhote-Alin Zapovednik: ecology and conservation | publisher = PSP | location = Vladivostok, Russia}}</ref><ref name="Seryodkin_PhD">{{cite web |url= http://uml.wl.dvgu.ru/rscv.php?id=74 |title= The ecology, behavior, management and conservation status of brown bears in Sikhote-Alin (in Russian) |author= Seryodkin, Ivan |year=2006 |publisher= Far Eastern National University, Vladivostok, Russia|pages=pp.1-252}}</ref>  (including adult male tigers: for instance, in 1972, Pogranichny.<ref name="Nikolaev-Yudin">{{cite web |url= http://tigers.ru/articles/nickl_e.html |title= CONFLICTS BETWEEN MAN AND TIGER IN THE RUSSIAN FAR EAST  |author= Igor G. Nikolaev and Victor G. Yudin |year=1993 |publisher= "Bulletin Moskovskogo  obshchestva  ispytateley
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Prirody", v. 98, i. 3|}}</ref>) Brown bear/tiger conflict can eliminate the weakest animals from both populations. <ref>{{cite book | author = Seryodkin, I. V., J. M. Goodrich, A. V. Kostyrya, B. O. Schleyer, E. N. Smirnov, L. L. Kerley, and D. G. Miquelle| date= 2005 | title =Relationship between tigers, brown bears, and Himalayan black bears. Pages 156-163 in Miquelle, D. G., E. N. Smirnov, and J. M. Goodrich, editors, Tigers of Sikhote-Alin Zapovednik: ecology and conservation | publisher = PSP | location = Vladivostok, Russia}}</ref><ref name="Seryodkin_PhD">{{cite web |url= http://uml.wl.dvgu.ru/rscv.php?id=74 |title= The ecology, behavior, management and conservation status of brown bears in Sikhote-Alin (in Russian) |author= Seryodkin, Ivan |year=2006 |publisher= Far Eastern National University, Vladivostok, Russia|pages=pp.1-252}}</ref>
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Adult bears are generally immune from predatory attacks from anything other than another bear. Some bears emerging from hibernation have been known to seek out [[tiger]]s in order to steal their kills (Matthiessen and Hornocker 2001). However, in the [[Russian Far East]], brown bears, along with smaller [[Asiatic black bear]]s, constitute 5 to 8 percent of the diet of [[Siberian tiger]]s (Mazak 1983). In particular, the brown bear's input is estimated as 1 to 1.5 percent. However, tigers prefer to contest brown bear sows (Seryodkin 2006). For the tiger, even bears of the same size are a force to be reckoned with when confronted head on. There are 12 known incidents when Siberian tigers were killed and eaten by brown bears (Seryodkin et al. 2005; Seryodkin 2006). Brown bear/tiger conflict can eliminate the weakest animals from both populations (Seryodkin et al. 2005; Seryodkin 2006).  
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Brown bears usually dominate other bear species in areas where they coexist. Due to their smaller size, [[American black bear]]s are at a competitive disadvantage over brown bears in open, non-forested areas. Although displacement of black bears by brown bears has been documented, actual interspecific killing of black bears by brown bears has only occasionally been reported. The black bear's habit of living in heavily forested areas as opposed to the brown bear's preference for open spaces usually ensures that the two species avoid confrontations in areas where they are sympatric.
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There has been a recent increase in interactions between brown bears and [[polar bear]]s. Brown bears have been seen moving increasingly northward into territories formerly claimed by polar bears. Brown bears tend to dominate polar bears in disputes over carcasses, and dead polar bear cubs have been found in brown bear dens (Dye 2005).
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[[Giant panda]] cubs have also been reportedly eaten by brown bears (Brown 1993).  
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==Taxonomy==
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There is little agreement on classification of brown bears. Some systems have proposed as many as 90 subspecies, while recent [[DNA]] analysis has identified as few as five clades (FWS 2005). DNA analysis has recently revealed that the identified subspecies of brown bears, both Eurasian and North American, are genetically quite homogeneous, and that their genetic [[phylogeography]] does not correspond to their traditional taxonomy (Waits et al. 1998). The subspecies of brown bears have been listed as follows (one of which, called clade I by Waits et al. (1998), part of the subspecies identified as ''U. a. sitkensis,'' by Hall and ''U. a. dalli'' by Kurtén, appears to be more closely related to the [[polar bear]] than to other brown bears (Waits et al. 1998)):
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* ''Ursus arctos arctos''—[[Eurasian brown bear]]
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* ''Ursus arctos ognevi''—East from Kolyma River
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* ''Ursus arctos beringianus''—[[Kamchatka brown bear]]; Kamchatka Peninsula and Paramushir Island
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* ''Ursus arctos californicus—California golden bear (extinct)
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* ''Ursus arctos crowtheri''—[[Atlas bear]] (extinct)
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* ''Ursus arctos gobiensis''—Gobi bear; Mongolia
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* ''Ursus arctos horribilis''—[[Grizzly bear]]; Canada and United States
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* ''Ursus arctos isabellinus''—[[Himalayan brown bear]]; Nepal, Pakistan and Northern India
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* ''Ursus arctos formicarius''--Carpathian bear;
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[[Image:polarbrown-1.jpg|200px|thumb|Polar/brown bear hybrid, Rothschild Museum, Tring]]
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* ''Ursus arctos lasiotus''—[[Amur brown bear]] ( or "Ussuri brown bear," "black grizzly," or "horse bear"), [[Russia]]: Southern [[Kuril Islands]], [[Sakhalin]], [[Maritime Territory]], and the [[Ussuri]]/[[Amur]] river region south of the [[Stanovoy Range]]. [[People's Republic of China|China]]: Northeastern [[Heilongjiang]]. [[Japan]]: [[Hokkaidō]]
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* ''Ursus arctos marsicanus''—[[Marsican brown bear]]; Central Italy (critically endangered)
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* ''Ursus arctos meridionalis''—Northern Caucasus
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* ''Ursus arctos middendorffi''—[[Kodiak bear]]; Kodiak, Afognak, Shuyak Islands (Alaska)
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* ''Ursus arctos nelsoni''—[[Mexican grizzly bear]]; (extinct)
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* ''Ursus arctos collaris''—[[Siberian brown bear]]; Siberia (except for the habitat of the Kamchatka and Amur brown bears.) Also in northern Mongolia, far northern Xinjiang, and extreme eastern Kazakhstan.
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* ''Ursus arctos pruinosus''—Tibetan [[blue bear]]; Western China
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* ''Ursus arctos syriacus''—[[Syrian brown bear]]; Middle East
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* ''Ursus arctos yesoensis''--Hokkaido brown bear; Japan
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* ''Ursus arctos piscator''—Bergman's bear (extinct?)
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===Hybrids===
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A [[grizzly–polar bear hybrid]] is a rare [[ursid hybrid]] resulting from a union of a brown bear and a [[polar bear]]. It has occurred both in captivity and in the wild. In 2006, the occurrence of this hybrid in nature was confirmed by testing the [[DNA]] of a strange-looking bear that had been shot in the [[Canada|Canadian]] [[arctic]] (AP 2008). Previously, the hybrid had been produced in zoos and was considered a "[[Cryptozoology|cryptid]]" (a hypothesized animal for which there is no scientific proof of existence in the wild).  
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==Brown bear in prehistory==
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===North America===
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The brown bear has existed in North America since at least the most recent ice age, though it is thought that the larger, taller, and stronger [[Arctodus simus|giant short-faced bear]], or bulldog bear, was the dominant carnivore at the time. The giant short-faced bear was a tall, thin animal adapted to eating large mammals, whereas the grizzly or brown bear has teeth appropriate for its [[omnivorous]] diet.  
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The brown bear also shared North America with the [[American lion]] and [[Smilodon]], carnivorous competitors. The modern grizzly can eat plants, insects, carrion, and small and large animals. The American lion, Smilodon, and giant short-faced bear had a more limited range of food, making them vulnerable to starvation as the supply of available large mammals decreased, possibly due to hunting by humans.
  
Brown bears usually dominate other bear species in areas where they coexist. Due to their smaller size, [[American black bear]]s are at a competitive disadvantage over brown bears in open, non-forested areas. Although displacement of black bears by brown bears has been documented, actual interspecific killing of black bears by brown bears has only occasionally been reported. The diurnal black bear's habit of living in heavily forested areas as opposed to the largely nocturnal brown bear's preference for open spaces usually ensures that the two species avoid confrontations in areas where they are sympatric.<ref>[http://www.nrmsc.usgs.gov/products/Predation_Papers.pdf Notes<!-- Bot generated title —>]</ref>
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The time of the ''Arctodus'' extinction is about the same as the extinction of the [[long-horned bison]] and other [[megafauna]]. Both of these animals were replaced by Eurasian immigrants, specifically the brown bear and [[American bison]]. Since this was also about the same time as the [[Clovis]] tool kit hunting culture appeared in North America, with culturally advanced humans entering the Americas from Asia, the implication is that the brown bear was better adapted to human competition than the megafauna, presumably due to a long term coexistence in the Old World with people.  
There has been a recent increase in interactions between brown bears and [[polar bear]]s, theorized to be caused by [[global warming]]. Brown bears have been seen moving increasingly northward into territories formerly claimed by polar bears. Brown bears tend to dominate polar bears in disputes over carcasses<ref>[http://dwb.adn.com/front/story/6415667p-6294323c.html adn.com | front : Polar bears, grizzlies increasingly gather on North Slope<!Bot generated title >]</ref>, and dead polar bear cubs have been found in brown bear dens.<ref>[http://abcnews.go.com/Technology/DyeHard/Story?id=582243&page=3 ABC News: Grizzlies Encroaching on Polar Bear Country<!-- Bot generated title —>]</ref> [[Giant Panda]] cubs have also been reportedly eaten by brown bears.<ref name="Bearalmanac">{{cite book | author = Brown, Gary | title = Great Bear Almanac | year = 1996 | pages = pp.340 | isbn = 1558214747}}</ref>
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The extinction of ice-age herbivorous megafauna resulted in the extinction of the [[sabertooth]], American lion, and giant short-faced bear, leaving the brown bear as the major large predator in North America, with the [[gray wolf]], the [[jaguar]] in the south, the [[American black bear]], and [[cougar]] also competing for large prey. The origin of human presence in America is widely accepted to have occurred across the [[Bering Land Bridge]] with the largest known immigration being that of the [[Paleo Indians]] at about the last ice age, bringing with them the [[Clovis point]] and advanced hunting techniques. When the last ice age ended about 10,000 years ago, brown bears from farther south in North America slowly expanded their range northward and back up into Alaska. Today there are three [[genetically]] distinct grizzly bear [[clade]]s in North America: The Alaskan-Yukon Grizzly, the Alberta-[[Saskatchewan]] lineage, and those found in the Colorado-Washington-Idaho-Montana-Wyoming area.
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===Eurasia===
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In Europe, the brown bear shared its habitat with other predators such as the [[cave lion]], [[cave hyena]], and the larger, closely related [[cave bear]], which the brown bear ultimately outlasted. The cave bear was hunted by [[Neanderthal]]s who may have had a religion relating to this bear, the [[Cave Bear Cult]]. However, the Neanderthal population was too small for their consumption of cave bear to result in the species' extinction, and the cave bear outlasted the Neanderthals by 18,000 years, becoming extinct about 10,000 years ago. The cave bear and brown bear diets were similar, and the two species probably lived in the same area at the same time. Why the cave bear died out is not known.
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The Caledonian bear was said to be so fierce that it was favored by the Romans who used them in their amphitheatres.
  
 
==Relationship with humans==
 
==Relationship with humans==
 
[[Image:BärenspurP1050395.jpg|thumb|Front paw imprint.]]
 
[[Image:BärenspurP1050395.jpg|thumb|Front paw imprint.]]
 
[[Image:Grizzly rear paw print.jpg|thumb|Rear paw imprint.]]
 
[[Image:Grizzly rear paw print.jpg|thumb|Rear paw imprint.]]
Bears become attracted to human created food sources such as garbage dumps, litter bins, and dumpsters; and venture into human dwellings or barns in search of food as humans encroach into bear habitat. In the U.S., bears sometimes kill and eat farm animals. When bears come to associate human activity with a "food reward", a bear is likely to continue to become emboldened and the likeliness of human-bear encounters increases, as they may return to the same location despite relocation. The saying, "a fed bear is a dead bear," has come into use to popularize the idea that allowing bears to scavenge human garbage, such as trash cans and campers' backpacks, pet food, or other food sources that draw the bear into contact with humans can result in a bear's death.  
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Bears become attracted to human created food sources such as garbage dumps, litter bins, and dumpsters; and venture into human dwellings or barns in search of food as humans encroach into bear habitat. In the [[United States]], bears sometimes kill and eat farm animals. When bears come to associate human activity with a "food reward," a bear is likely to continue to become emboldened and the likeliness of human-bear encounters increases, as they may return to the same location despite relocation. The saying, "a fed bear is a dead bear," has come into use to popularize the idea that allowing bears to scavenge human garbage, such as trash cans and campers' backpacks, pet food, or other food sources that draw the bear into contact with humans can result in a bear being put into a situation where it has to be killed for safety reasons.  
  
Relocation has been used to separate the bear from the human environment, but it does not address the problem bear's newly learned humans-as-food-source behavior. Nor does it address the environmental situations which created the human habituated bear. "Placing a bear in habitat used by other bears may lead to competition and social conflict, and result in the injury or death of the less dominant bear."<ref>{{cite web |url=http://www.bearsmart.com/managingBears/Relocation.html |title=http://www.bearsmart.com/managingBears/Relocation.html |accessdate= |format= |work= }}</ref>
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Relocation has been used to separate the bear from the human environment, but it does not address the problem bear's newly learned humans-as-food-source behavior. Nor does it address the environmental situations which created the human habituated bear. And attracting multiple bears to an area can lead to competition, social conflict, and bear-on-bear injuries and death.
  
[[Yellowstone National Park]], an enormous reserve located in the Western United States, contains prime habitat for the Grizzly Bear (''Ursus arctos horribilis''), but due to the enormous number of visitors, human-bear encounters are common. The scenic beauty of the area has led to an influx of people moving into the area. In addition, because there are so many bear relocations to the same remote areas of Yellowstone, and because male bears tend to dominate the center of the relocation zone, female bears tend to be pushed to the boundaries of the region and beyond. The result is that a large proportion of repeat offenders, bears that are killed for public safety, are females. This creates a further depressive effect on an already endangered species. The grizzly bear is officially described as ''threatened'' in the U.S. Though the problem is most significant with regard to grizzlies, these issues affect the other types of brown bear as well.
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[[Yellowstone National Park]], an enormous reserve located in the Western United States, contains prime habitat for the grizzly bear ''(Ursus arctos horribilis)'', but due to the enormous number of visitors, human-bear encounters are common. The scenic beauty of the area has led to an influx of people moving into the area. In addition, because there are so many bear relocations to the same remote areas of Yellowstone, and because male bears tend to dominate the center of the relocation zone, female bears tend to be pushed to the boundaries of the region and beyond. The result is that a large proportion of repeat offenders, bears that are killed for public safety, are females. This creates a further depressive effect on an already stressed population size. The grizzly bear is officially described as ''threatened'' in the United States. Although the problem is most significant with regard to grizzlies, these issues affect the other types of brown bear as well.
  
In Europe, part of the problem lies with [[shepherd]]s; over the past two centuries, many sheep and goat herders have gradually abandoned the more traditional practice of using [[dog]]s to guard flocks, which have concurrently grown larger. Typically they allow the herds to graze freely over sizeable tracts of land. As bears reclaim parts of their range, they may eat livestock. In some cases, the shepherd will shoot the bear thinking that his livelihood is under threat. Many are now better informed about the ample compensation available and will make a claim when a loss to his livestock due to a bear takes place.
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In Europe, part of the problem lies with [[shepherd]]s; over the past two centuries, many [[sheep]] and goat herders have gradually abandoned the more traditional practice of using [[dog]]s to guard flocks, which have concurrently grown larger. Typically, they allow the herds to graze freely over sizable tracts of land. As bears reclaim parts of their range, they may eat [[livestock]]. In some cases, the shepherd will shoot the bear thinking that his livelihood is under threat. Many shepherds are now better informed about the ample compensation available in some areas and will make a claim when a loss to his livestock due to a bear takes place.
  
 
===Legal status===
 
===Legal status===
*The grizzly bear, sometimes called the ''silvertip bear'', is listed as threatened in the [[Continental United States]]. It is slowly repopulating in areas where it was previously extirpated, though it is still vulnerable.
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*The grizzly bear, sometimes called the ''silvertip bear,'' is listed as threatened in the [[Continental United States]]. It is slowly repopulating in areas where it was previously extirpated, though it is still vulnerable.
*The [[California golden bear]] (''Ursus arctos californicus''<ref>{{cite web |url= http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=726987 |title= Ursus arctos californicus|accessmonthday= April 1 |accessyear= 2008 |author= Wilson, Don E., and DeeAnn M. Reeder, eds. |publisher= Johns Hopkins University Press}}</ref>) disappeared from the state of [[California]] in 1922 when the last one was shot in [[Tulare County, California|Tulare County]], but it is still on the state [[flag of California]]. The bear is alluded to in the names of the sports teams of the [[University of California, Berkeley]] (the [[California Golden Bears]]), and of the [[University of California, Los Angeles]] (the [[UCLA Bruins]]) and in the mascot of [[University of California, Riverside]] (Scottie the Bear, dressed in a Highland [[kilt]]).
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*The [[California golden bear]] ''(Ursus arctos californicus)'' disappeared from the state of [[California]] in 1922, when the last one was shot in [[Tulare County, California|Tulare County]], but it is still on the state [[flag of California]]. The bear is alluded to in the names of the sports teams of the [[University of California, Berkeley]] (the [[California Golden Bears]]), and of the [[University of California, Los Angeles]] (the [[UCLA Bruins]]), and in the mascot of [[University of California, Riverside]].
 
*The Mexican grizzly bear is listed as an [[endangered species]], but it may be extinct.
 
*The Mexican grizzly bear is listed as an [[endangered species]], but it may be extinct.
*In Canada, it is listed as vulnerable in Alberta, British Columbia, Northwest Territories, and Yukon Territory. Prairie populations of grizzly bear are listed as extirpated in Alberta, Manitoba, and Saskatchewan.
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*In Canada, the brown bear is listed as vulnerable in Alberta, British Columbia, Northwest Territories, and Yukon Territory. Prairie populations of grizzly bear are listed as extirpated in Alberta, Manitoba, and Saskatchewan.
 
*The brown bear is a [[European Protected Species]], given protection throughout the [[European Union]].
 
*The brown bear is a [[European Protected Species]], given protection throughout the [[European Union]].
*The brown bear is also the national animal of [[Finland]] and [[Slovenia]].
 
  
 
===Bear encounters===
 
===Bear encounters===
There are an average of two fatal attacks a year in North America.<ref>''Bear Attacks: Their Causes and Avoidance'', Stephen Herrero, revised edition, 2002.</ref> In [[Scandinavia]], there are only four known cases since 1902 of bear encounters which have resulted in death. The two most common causes for bear attack are surprise and curiosity.<ref name="akscience">{{cite web |url= http://www.absc.usgs.gov/research/brownbears/attacks/bear-human_conflicts.htm|title= Ursus arctos californicus|accessmonthday= April 12 |accessyear= 2008 |author= WTom S. Smith, Ph.D. and Steven Herrero, Ph.D. |publisher= Alaska Science Center - Biological Science Office}}</ref> Some types of bears, such as [[polar bear]]s, are more likely to attack humans when searching for food, while [[American black bear]]s are much less likely to attack.
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There are an average of two fatal bear attacks a year in North America (Herrero 2002). In [[Scandinavia]], there are only four known cases since 1902 of bear encounters that have resulted in death. The two most common causes for bear attack are surprise and curiosity (Smith and Herrero 2007).  
 +
 
 +
Some types of bears, such as [[polar bear]]s, are more likely to attack humans when searching for food, while [[American black bear]]s are much less likely to attack.
  
The Alaska Science Center ranks the following as the most likely reasons for bear attacks:<ref name="akscience">{{cite web |url= http://www.absc.usgs.gov/research/brownbears/attacks/bear-human_conflicts.htm|title= Ursus arctos californicus|accessmonthday= April 12 |accessyear= 2008 |author= WTom S. Smith, Ph.D. and Steven Herrero, Ph.D. |publisher= Alaska Science Center - Biological Science Office}}</ref>
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The Alaska Science Center ranks the following as the most likely reasons for bear attacks (Smith and Herrero 2007):
  
 
* 1) Surprise
 
* 1) Surprise
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* 6) Carcass defense
 
* 6) Carcass defense
 
* 7) Provoked charge
 
* 7) Provoked charge
 
===History of bear defense===
 
Because of the unreliability of pepper spray, guns have been the preferred method of defense from bears.<ref name="smith_brown_bear_projects">{{cite web
 
|url=http://www.absc.usgs.gov/research/brownbears/safety/safeconduct.htm
 
|title=Brown Bear Projects at the Alaska Science Center
 
|publisher=Alaska Science Center - Biological Science Office
 
|accessdate=2008-06-02
 
|last=Smith
 
|first=Tom S.
 
}}</ref>  Too often people do not carry a proper caliber weapon to neutralize the bear.  According to the Alaska Science Center, a [[Gauge (bore diameter)|12 gauge]] [[shotgun]] with [[Slug (projectile)|slugs]] has been the most effective weapon.  There have been fewer injuries as a result of only carrying lethal loads in the shotgun, as opposed to deterrent rounds.  State of Alaska Defense of Life or Property (DLP) laws require you to report the kill to authorities, and salvage the hide, skull and claws.<ref name="casenumber_07-96958">
 
{{cite web
 
|url=http://www.dps.state.ak.us/pio/dispatch/Trooper%20Dispatches%20of%2011-19-2007.20071119.txt
 
|title=Alaska State Troopers Press Release of Monday, November 19, 2007
 
|publisher=Alaska Department of Public Safety
 
|accessdate=2008-06-02
 
|date=2007-11-19
 
|last=
 
|first=
 
|format=Case Number: 07-96958
 
}}
 
</ref>
 
 
If a bear is killed near camp the bear’s carcass must be adequately disposed of, including entrails and blood if possible.  Failure to move the carcass has often resulted in it attracting other bears and further exacerbating a bad situation.<ref name="smith_brown_bear_projects"/>
 
 
  
 
==Notes==
 
==Notes==
{{reflist}}
+
<references/>
  
 
==References==
 
==References==
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* Bellemain, E., J. E. Swenson, and P. Taberlet. [http://www.ingentaconnect.com/content/bsc/eth/2006/00000112/00000003/art00004;jsessionid=6580enj8ip2kk.alice?format=print Mating strategies in relation to sexually selected infanticide in a non-social carnivore: The brown bear]. ''Ethology'' 112(3) (2006): 238-246.
 +
* Brown, G. ''Great Bear Almanac''. New York: Lyons & Buford, 1996. ISBN 1558212108
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* Cameron, W. Learn to identify black bears and grizzly (brown) bears. ''Mountain Nature'' 2005.
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* Dewey, T., and L. Ballenger. [http://animaldiversity.ummz.umich.edu/site/accounts/information/Ursus_arctos.html ''Ursus arctos'']. ''Animal Diversity Web,'' 2002. Retrieved April 29, 2020.
 +
* Herrero, S. ''Bear Attacks: Their Causes and Avoidance,'' revised edition. Guilford, CT: Lyons Press, 2002. ISBN 158574557X
 +
* Macdonald, D. ''The Encyclopedia of Mammals''. London: Allen & Unwin, 1984. ISBN 004500028X
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* Matthiessen, P., and M. Hornocker. ''Tigers In The Snow''. North Point Press, 2001. ISBN 0865475962
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* Mazak, V. ''Der Tiger: Panthera tigris''. Nachdruck der 3. Auflage von 1983. Westarp Wissenschaften Hohenwarsleben, 2004. ISBN 3894327596
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* Russian Hunting Agency (RHA). [http://www.russianbearhunt.com/ Brown bear hunting in Russia]. ''Russian Hunting Agency'', 2007. Retrieved April 29, 2020.
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* Seryodkin, I. V., J. M. Goodrich, A. V. Kostyrya, B. O. Schleyer, E. N. Smirnov, L. L. Kerley, and D. G. Miquelle. "Relationship between tigers, brown bears, and Himalayan black bears."  In ''Tigers of Sikhote-Alin Zapovednik: Ecology and Conservation,'' edited by  D. G. Miquelle, E. N. Smirnov, and J. M. Goodrich, 156-163. Vladivostok, Russia: PSP, 2005.
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* Waits, L. P., S. L. Talbot, R. H. Ward, and G. F. Shields. Mitochondrial DNA phylogeography of the North American brown bear and implications for conservation. ''Conservation Biology'' 12(2) (1998): 408-417.
 +
* Wood, G. L. ''The Guinness Book of Animal Facts and Feats''. Sterling Pub Co., 1983. ISBN 978-0851122359
  
* McLellan, B. N., C. Servheen, and D. Huber. 2008. [http://www.iucnredlist.org/details/41688 ''Ursus arctos'']. In IUCN, ''2008 IUCN Red List of Threatened Species''. Retrieved December 28, 2008.  
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==External links==
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All links retrieved November 21, 2023.
  
==External links==
 
 
*[http://www3.nationalgeographic.com/animals/mammals/brown-bear.html Brown Bear profile] from National Geographic
 
*[http://www3.nationalgeographic.com/animals/mammals/brown-bear.html Brown Bear profile] from National Geographic
 
*[http://www.thomasoneil.com/species2.php?n=502 Brown Bear images] from British Columbia, Alaska and Yellowstone.
 
*[http://www.thomasoneil.com/species2.php?n=502 Brown Bear images] from British Columbia, Alaska and Yellowstone.
 
*[http://www.medvede.sk/index1.php The Bears Project] information, reports and images of European brown bears
 
*[http://www.medvede.sk/index1.php The Bears Project] information, reports and images of European brown bears
*[http://www.wildanimalsonline.com/mammals/brownbear-grizzly.php Brown Bear facts and photography] at WildAnimalsOnline.com free online encyclopedia
 
*[http://www.ifaw.org/ifaw/general/default.aspx?oid=34751 IFAW] Rebuilding the European Brown Bear Population
 
 
*[http://www.sciencedaily.com/releases/2007/11/071126115307.htm Bear Hunting Altered Genetics More Than Ice Age Isolation]
 
*[http://www.sciencedaily.com/releases/2007/11/071126115307.htm Bear Hunting Altered Genetics More Than Ice Age Isolation]
 
*[http://www.sciencedaily.com/releases/2004/11/041115002514.htm Ancient Fossil Offers New Clues To Brown Bears Past]
 
*[http://www.sciencedaily.com/releases/2004/11/041115002514.htm Ancient Fossil Offers New Clues To Brown Bears Past]
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{{Carnivora|C.}}
 
{{Carnivora|C.}}
  
 
{{DEFAULTSORT:Bear, Brown}}
 
  
 
[[Category:Life sciences]]
 
[[Category:Life sciences]]

Latest revision as of 04:37, 22 November 2023

Brown bear
Grizzly bear (U. arctos horribilis)
Grizzly bear (U. arctos horribilis)
Conservation status
Status iucn2.3 LC.svg
Least Concern

(IUCN) [1]

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Ursidae
Genus: Ursus
Species: U. arctos
Binomial name
Ursus arctos
Linnaeus, 1758
Ursus arctos range map.
Ursus arctos range map.

Brown bear is the common name for a large bear, Ursus arctos, ranging in color from a common brown to yellowish or black fur and having a noticeable shoulder hump and a concave face. The most widely distributed member of the bear family, Ursidae, it is found in much of northern Eurasia and North America. Other well-known common names for various subspecies or populations include grizzly bear, Kodiak bear, Alaskan brown bear, Russian brown bear, Asiatic brown bear, Himalayan snow bear, and European brown bear. The brown bear sometimes is referred to as the "bruin."

The brown bear is a massive animal, weighing between 100 and 700 kilograms (220-1,500 pounds) and its larger populations, such as the Kodiak bear, match the polar bear as the largest extant land carnivores. While the brown bear's range has shrunk, and it has faced local extinctions, it remains listed as a least concern species with a total population of approximately 200,000. Its principal range countries are Russia, the United States (especially Alaska), Canada, and Finland.

The species primarily feeds on vegetable matter, including roots and berries, as well as fungi. Fish are a primary source of meat, and it will also kill small mammals on land. Larger mammals, such as deer, are taken only occasionally. Adult brown bears can match wolf packs and large felines, often driving them off their kills. As a seed disperser and predator, it plays an important role in the ecosystem.

While encounters with the brown bear in the wild can be dangerous for humans, these remarkable animals also add greatly to the wonder of nature and are prized sightings on ecotours. They also are popular trophies in sports hunting. Once sought for their meat and hides, they are less commonly used for such purposes. Extraction of bear bile, used in Traditional Chinese Medicine (TCM), is reported to involve a great deal of cruelty for the animals (see bile).

Description

A Eurasian brown bear running.

Brown bears have heads that are large and round with a concave facial profile, a characteristic used to distinguish them from other bears. Their snout protrudes from this concave or "hollow" face (Grzimek et al. 2004). They also have a large hump of muscle over their shoulders (Grzimek et al. 2004), which helps to distinguish them from such species as the black bear (Ursus americanus), which lacks this characteristic hump (Cameron 2005). Their tail is short, 10 to 13 centimeters (4 to 5 inches) long (Brown 1993).

The forearms of brown bears end in massive paws with claws up to 15 centimeters (6 inches) in length, which are mainly used for digging. Brown bear claws are not retractable, and have relatively blunt points. Like all bears, brown bears are plantigrades and can stand up on their hind legs for extended periods of time.

Brown bears have fur in shades of brown, black, tan or blond, or a combination of those colors. The longer outer guard hairs of the brown bear are often tipped with white or silver, giving a "grizzled" appearance.

Brown bears are large and very powerful, and can break the backs and necks of large prey. Males are 38 to 50 percent larger than females (Brown 1993). The normal range of physical dimensions for a brown bear is a head-and-body length of 1.7 to 2.8 meters (5.6-9.2 feet) and a shoulder height 90 to 150 centimeters (35-60 inches). The smallest subspecies is the Eurasian brown bear with mature females weighing as little as 90 kilograms (200 pounds) (Wood 1983). Barely larger, [grizzly bear]]s from the Yukon region (which are a third smaller than most grizzlies) can weigh as little as 100 kilograms (220 lb) in the spring (BF), and mature females of the Syrian brown bear weigh as little as 150 kilograms (331 pounds). The largest subspecies of the brown bear are the Kodiak bear, Siberian brown bear, and the bears from coastal Russia and Alaska. It is not unusual for large male Kodiak bears to stand over 3 meters (10 feet) while on their hind legs and to weigh about 680 kilograms (1,500 lb). The largest wild Kodiak bear on record weighed over 1,100 kilograms (2,500 pounds) (Brown 1993).

Size seems related to food availability, with subspecies distinctions being more related to nutrition rather than geographical location (Macdonald 1984). Bears raised in zoos are often heavier than wild bears because of regular feeding and limited movement. In zoos, bears may weigh up to 900 kilograms (2,000 pounds).

Distribution and habitat

Brown bear at Brooks Falls.

The most widely distributed ursid (McLellan et al. 2008), the brown bear has a global distribution, with populations in North America, Europe, northern Asia, and Japan (Grzimek et al. 2004). It occupies about 5 million square kilometers of North America, 800,000 square kilometers of Europe (excluding Russia), and much of northern Asia (McLellan et al. 2008).

There are about 200,000 brown bears in the world. The largest populations are in Russia, with 120,000, the United States with 32,500, and Canada with 21,750. Ninety-five percent of the brown bear population in the United States is in Alaska, though in the western United States they are repopulating slowly but steadily along the Rockies and plains. In Europe, there are 14,000 brown bears in ten separate fragmented populations, from Spain in the west, to Russia in the east, and from Scandinavia in the north to Romania, Bulgaria, and Greece (with about 200 animals) in the south. They are extinct in the British Isles, extremely threatened in France and Spain, and in trouble over most of Central Europe. The brown bear is Finland's national animal. The Carpathian brown bear population is the largest in Europe outside Russia, estimated at 4,500 to 5,000 bears.

Brown bears were once native to the Atlas Mountains in Africa, and may have existed as late as the mid-1800s in Algeria and Morocco and as late as 1500s in the Sinai of Egypt, but are not extinct in these areas (McLellan et al. 2008). They also were once in Mexico, but were extirpated there and in a large portion of the southwestern United States during the twentieth century (McLellan et al. 2008). Although many hold on to the belief that some brown bears still may be present in Mexico and the Atlas Mountains of Morocco, both are almost certainly extinct. The last known Mexican brown bear was shot in 1960. Very small numbers remain in Iraq and Nepal, but they have apparently been eliminated from Syria and possibly Bhutan (McLellan et al. 2008).

Brown bears live in Alaska, east through the Yukon and Northwest Territories, south through British Columbia and through the western half of Alberta. Small populations exist in the Greater Yellowstone ecosystem of northwest Wyoming (with about 600 animals), the Northern Continental Divide ecosystem of northwest Montana (with about 400-500 animals), the Cabinet-Yaak ecosystem of northwest Montana and northeast Idaho (with about 30-40 animals), the Selkirk ecosystem of northeast Washington and northwest Idaho (with about 40-50 animals), and the North Cascades ecosystem of north-central Washington (with about 5-10 animals). These five ecosystems combine for a total of roughly 1,200 wild grizzlies still persisting in the contiguous United States. Unfortunately, these populations are isolated from each other, inhibiting any genetic flow to occur between ecosystems. This poses one of the greatest threats to the future survival of the grizzly bear in the contiguous United States.

The population of brown bears in the Pyrenees mountain range between France and Spain is so low, estimated at fourteen to eighteen with a shortage of females, that bears, mostly female, from Slovenia were released in the spring of 2006 to alleviate the imbalance and preserve the species' presence in the area, despite protests from French farmers.

In Arctic areas, the potential habitat of the brown bear is increasing. The seeming warming of that region has allowed the species to move farther and farther north into what was once exclusively the domain of the polar bear. In non-Arctic areas, habitat loss is blamed as the leading cause of endangerment, followed by hunting.

North American brown bears seem to prefer open landscapes, whereas in Eurasia they inhabit mostly dense forests. It is thought that the Eurasian bears that colonized America were tundra adapted, something indicated by brown bears in the Chukotka Peninsula on the Asian side of Bering Strait, which are the only Asian brown bears to live year-round in lowland tundra like their American cousins (RHA 2007).

Behavior

The brown bear is primarily solitary animals, although they may gather in large numbers at major food sources and form social hierarchies based on age and size (Dewey and Ballenger 2002; Grzimek et al. 2004). They may be active at any time, but primarily forage in the morning and at dusk, and rest during the day (Dewey and Ballenger 2002).

In the summer, the brown bear may put on substantial reserves of fat (up to 180 kilograms or 400 pounds of fat in larger populations), on which it relies to make it through winter, when it becomes very lethargic. Although they are not full hibernators, and can be woken easily, both sexes like to den in a protected spot such as a cave, crevice, or hollow log during the winter months.

Reproduction

The mating season takes place from late May through early July. Being serially monogamous, brown bears will remain with the same mate from several days to a couple of weeks. Females become sexually mature between the age of 5 and 7 years, while males will usually not mate until a few years later when they are large and strong enough to successfully compete with other males for mating rights.

Through the process of delayed implantation, a female's fertilized egg will divide and float free within the uterus for six months. During winter dormancy, the fetus will attach itself to the uterine wall and the cubs will be born after an eight-week period while the mother sleeps. Should the mother not gain enough weight to survive through the winter, the embryo will not implant and be reabsorbed into the body.

The average litter number is between one and four, with two being the most common number, though there have been cases of bears with five cubs, though it is not unusual for females to adopt strange cubs. The size of a litter depends on a number of factors, such as the age of the mother, geographic location, and food supply. Older females tend to give birth to larger litters.

The cubs are born blind, toothless, hairless and weigh less than 1 pound at birth. They feed on their mother’s milk until spring and as late as early summer depending on climate conditions. The cubs, which will weigh from 15 to 20 pounds at this time, will have developed enough to follow her and begin to forage for solid food.

Cubs will remain with their mother from two to four years, during which time they will learn survival techniques such as which foods have the highest nutritional values and where to attain them, how to hunt, how to fish, how to defend themselves and where to den. The cubs learn by following and imitating their mother’s actions during the period they are with her (SOTB).

Brown bears engage in infanticide (Bellemain et al. 2006). An adult male bear may kill the cubs of another bear either to make the female sexually receptive or simply for consumption. Cubs will flee up a tree when they sight a strange male bear and the mother will defend them even though the male may be twice her size.

Dietary habits

Brown bear feeding on salmon.

Brown bears are omnivores and feed on a variety of plant products, including berries, roots, and sprouts, as well as fungi and meat products such as fish, insects, and small mammals. Despite their reputation, most brown bears are not particularly carnivorous as they typically derive up to 90 percent of their dietary food energy from vegetable matter (DCED). Their jaw structure has evolved to fit their dietary habits.

The diet of brown bearns varies enormously throughout their differing ranges. For example, bears in Yellowstone National Park during eat an enormous number of moths during the summer, sometimes as many as 40,000 in a day in August, and may derive up to half of their annual food energy from these insects (Reed 2006). Locally, in areas of Russia and Alaska, brown bears feed mostly on spawning salmon, and the nutrition and abundance of this food accounts for the enormous size of the bears from these areas. Brown bears also occasionally prey on deer, elk, moose, caribou, and bison. When brown bears attack these animals, they tend to choose the young ones since they are much easier to catch. When hunting, the brown bear uses its sharp canine teeth for neck-biting its prey. On rare occasions, bears kill by hitting their prey with their powerful forearms, which can break the necks and backs of large prey, such as bison. They also feed on carrion and will use their size to intimidate other predators such as wolves, cougars, and black bears from their kills.

Interspecific predatory relationships

Brown bears will often use their large size to intimidate wolves from their kills. Though conflict over carcasses is common, the two predators will, on rare occasions, tolerate each other on the same kill. Given the opportunity, both species will prey on each other's cubs.

Reconstruction of a brown bear confronting a wolf pack by Adolph Murie (1944).

Adult bears are generally immune from predatory attacks from anything other than another bear. Some bears emerging from hibernation have been known to seek out tigers in order to steal their kills (Matthiessen and Hornocker 2001). However, in the Russian Far East, brown bears, along with smaller Asiatic black bears, constitute 5 to 8 percent of the diet of Siberian tigers (Mazak 1983). In particular, the brown bear's input is estimated as 1 to 1.5 percent. However, tigers prefer to contest brown bear sows (Seryodkin 2006). For the tiger, even bears of the same size are a force to be reckoned with when confronted head on. There are 12 known incidents when Siberian tigers were killed and eaten by brown bears (Seryodkin et al. 2005; Seryodkin 2006). Brown bear/tiger conflict can eliminate the weakest animals from both populations (Seryodkin et al. 2005; Seryodkin 2006).

Brown bears usually dominate other bear species in areas where they coexist. Due to their smaller size, American black bears are at a competitive disadvantage over brown bears in open, non-forested areas. Although displacement of black bears by brown bears has been documented, actual interspecific killing of black bears by brown bears has only occasionally been reported. The black bear's habit of living in heavily forested areas as opposed to the brown bear's preference for open spaces usually ensures that the two species avoid confrontations in areas where they are sympatric.

There has been a recent increase in interactions between brown bears and polar bears. Brown bears have been seen moving increasingly northward into territories formerly claimed by polar bears. Brown bears tend to dominate polar bears in disputes over carcasses, and dead polar bear cubs have been found in brown bear dens (Dye 2005).

Giant panda cubs have also been reportedly eaten by brown bears (Brown 1993).

Taxonomy

There is little agreement on classification of brown bears. Some systems have proposed as many as 90 subspecies, while recent DNA analysis has identified as few as five clades (FWS 2005). DNA analysis has recently revealed that the identified subspecies of brown bears, both Eurasian and North American, are genetically quite homogeneous, and that their genetic phylogeography does not correspond to their traditional taxonomy (Waits et al. 1998). The subspecies of brown bears have been listed as follows (one of which, called clade I by Waits et al. (1998), part of the subspecies identified as U. a. sitkensis, by Hall and U. a. dalli by Kurtén, appears to be more closely related to the polar bear than to other brown bears (Waits et al. 1998)):

  • Ursus arctos arctos—Eurasian brown bear
  • Ursus arctos ognevi—East from Kolyma River
  • Ursus arctos beringianus—Kamchatka brown bear; Kamchatka Peninsula and Paramushir Island
  • Ursus arctos californicus—California golden bear (extinct)
  • Ursus arctos crowtheri—Atlas bear (extinct)
  • Ursus arctos gobiensis—Gobi bear; Mongolia
  • Ursus arctos horribilis—Grizzly bear; Canada and United States
  • Ursus arctos isabellinus—Himalayan brown bear; Nepal, Pakistan and Northern India
  • Ursus arctos formicarius—Carpathian bear;
Polar/brown bear hybrid, Rothschild Museum, Tring
  • Ursus arctos lasiotus—Amur brown bear ( or "Ussuri brown bear," "black grizzly," or "horse bear"), Russia: Southern Kuril Islands, Sakhalin, Maritime Territory, and the Ussuri/Amur river region south of the Stanovoy Range. China: Northeastern Heilongjiang. Japan: Hokkaidō
  • Ursus arctos marsicanus—Marsican brown bear; Central Italy (critically endangered)
  • Ursus arctos meridionalis—Northern Caucasus
  • Ursus arctos middendorffi—Kodiak bear; Kodiak, Afognak, Shuyak Islands (Alaska)
  • Ursus arctos nelsoni—Mexican grizzly bear; (extinct)
  • Ursus arctos collaris—Siberian brown bear; Siberia (except for the habitat of the Kamchatka and Amur brown bears.) Also in northern Mongolia, far northern Xinjiang, and extreme eastern Kazakhstan.
  • Ursus arctos pruinosus—Tibetan blue bear; Western China
  • Ursus arctos syriacus—Syrian brown bear; Middle East
  • Ursus arctos yesoensis—Hokkaido brown bear; Japan
  • Ursus arctos piscator—Bergman's bear (extinct?)

Hybrids

A grizzly–polar bear hybrid is a rare ursid hybrid resulting from a union of a brown bear and a polar bear. It has occurred both in captivity and in the wild. In 2006, the occurrence of this hybrid in nature was confirmed by testing the DNA of a strange-looking bear that had been shot in the Canadian arctic (AP 2008). Previously, the hybrid had been produced in zoos and was considered a "cryptid" (a hypothesized animal for which there is no scientific proof of existence in the wild).

Brown bear in prehistory

North America

The brown bear has existed in North America since at least the most recent ice age, though it is thought that the larger, taller, and stronger giant short-faced bear, or bulldog bear, was the dominant carnivore at the time. The giant short-faced bear was a tall, thin animal adapted to eating large mammals, whereas the grizzly or brown bear has teeth appropriate for its omnivorous diet.

The brown bear also shared North America with the American lion and Smilodon, carnivorous competitors. The modern grizzly can eat plants, insects, carrion, and small and large animals. The American lion, Smilodon, and giant short-faced bear had a more limited range of food, making them vulnerable to starvation as the supply of available large mammals decreased, possibly due to hunting by humans.

The time of the Arctodus extinction is about the same as the extinction of the long-horned bison and other megafauna. Both of these animals were replaced by Eurasian immigrants, specifically the brown bear and American bison. Since this was also about the same time as the Clovis tool kit hunting culture appeared in North America, with culturally advanced humans entering the Americas from Asia, the implication is that the brown bear was better adapted to human competition than the megafauna, presumably due to a long term coexistence in the Old World with people.

The extinction of ice-age herbivorous megafauna resulted in the extinction of the sabertooth, American lion, and giant short-faced bear, leaving the brown bear as the major large predator in North America, with the gray wolf, the jaguar in the south, the American black bear, and cougar also competing for large prey. The origin of human presence in America is widely accepted to have occurred across the Bering Land Bridge with the largest known immigration being that of the Paleo Indians at about the last ice age, bringing with them the Clovis point and advanced hunting techniques. When the last ice age ended about 10,000 years ago, brown bears from farther south in North America slowly expanded their range northward and back up into Alaska. Today there are three genetically distinct grizzly bear clades in North America: The Alaskan-Yukon Grizzly, the Alberta-Saskatchewan lineage, and those found in the Colorado-Washington-Idaho-Montana-Wyoming area.

Eurasia

In Europe, the brown bear shared its habitat with other predators such as the cave lion, cave hyena, and the larger, closely related cave bear, which the brown bear ultimately outlasted. The cave bear was hunted by Neanderthals who may have had a religion relating to this bear, the Cave Bear Cult. However, the Neanderthal population was too small for their consumption of cave bear to result in the species' extinction, and the cave bear outlasted the Neanderthals by 18,000 years, becoming extinct about 10,000 years ago. The cave bear and brown bear diets were similar, and the two species probably lived in the same area at the same time. Why the cave bear died out is not known.

The Caledonian bear was said to be so fierce that it was favored by the Romans who used them in their amphitheatres.

Relationship with humans

Front paw imprint.
Rear paw imprint.

Bears become attracted to human created food sources such as garbage dumps, litter bins, and dumpsters; and venture into human dwellings or barns in search of food as humans encroach into bear habitat. In the United States, bears sometimes kill and eat farm animals. When bears come to associate human activity with a "food reward," a bear is likely to continue to become emboldened and the likeliness of human-bear encounters increases, as they may return to the same location despite relocation. The saying, "a fed bear is a dead bear," has come into use to popularize the idea that allowing bears to scavenge human garbage, such as trash cans and campers' backpacks, pet food, or other food sources that draw the bear into contact with humans can result in a bear being put into a situation where it has to be killed for safety reasons.

Relocation has been used to separate the bear from the human environment, but it does not address the problem bear's newly learned humans-as-food-source behavior. Nor does it address the environmental situations which created the human habituated bear. And attracting multiple bears to an area can lead to competition, social conflict, and bear-on-bear injuries and death.

Yellowstone National Park, an enormous reserve located in the Western United States, contains prime habitat for the grizzly bear (Ursus arctos horribilis), but due to the enormous number of visitors, human-bear encounters are common. The scenic beauty of the area has led to an influx of people moving into the area. In addition, because there are so many bear relocations to the same remote areas of Yellowstone, and because male bears tend to dominate the center of the relocation zone, female bears tend to be pushed to the boundaries of the region and beyond. The result is that a large proportion of repeat offenders, bears that are killed for public safety, are females. This creates a further depressive effect on an already stressed population size. The grizzly bear is officially described as threatened in the United States. Although the problem is most significant with regard to grizzlies, these issues affect the other types of brown bear as well.

In Europe, part of the problem lies with shepherds; over the past two centuries, many sheep and goat herders have gradually abandoned the more traditional practice of using dogs to guard flocks, which have concurrently grown larger. Typically, they allow the herds to graze freely over sizable tracts of land. As bears reclaim parts of their range, they may eat livestock. In some cases, the shepherd will shoot the bear thinking that his livelihood is under threat. Many shepherds are now better informed about the ample compensation available in some areas and will make a claim when a loss to his livestock due to a bear takes place.

Legal status

  • The grizzly bear, sometimes called the silvertip bear, is listed as threatened in the Continental United States. It is slowly repopulating in areas where it was previously extirpated, though it is still vulnerable.
  • The California golden bear (Ursus arctos californicus) disappeared from the state of California in 1922, when the last one was shot in Tulare County, but it is still on the state flag of California. The bear is alluded to in the names of the sports teams of the University of California, Berkeley (the California Golden Bears), and of the University of California, Los Angeles (the UCLA Bruins), and in the mascot of University of California, Riverside.
  • The Mexican grizzly bear is listed as an endangered species, but it may be extinct.
  • In Canada, the brown bear is listed as vulnerable in Alberta, British Columbia, Northwest Territories, and Yukon Territory. Prairie populations of grizzly bear are listed as extirpated in Alberta, Manitoba, and Saskatchewan.
  • The brown bear is a European Protected Species, given protection throughout the European Union.

Bear encounters

There are an average of two fatal bear attacks a year in North America (Herrero 2002). In Scandinavia, there are only four known cases since 1902 of bear encounters that have resulted in death. The two most common causes for bear attack are surprise and curiosity (Smith and Herrero 2007).

Some types of bears, such as polar bears, are more likely to attack humans when searching for food, while American black bears are much less likely to attack.

The Alaska Science Center ranks the following as the most likely reasons for bear attacks (Smith and Herrero 2007):

  • 1) Surprise
  • 2) Curiosity
  • 3) Invaded personal space (this includes a mother bear protecting her young)
  • 4) Predatory
  • 5) Hunting wounded
  • 6) Carcass defense
  • 7) Provoked charge

Notes

  1. B. N. McLellan, C. Servheen, and D. Huber, "Ursus arctos,", 2008 IUCN Red List of Threatened Species (IUCN 2008). Retrieved December 28, 2008.

References
ISBN links support NWE through referral fees

  • Bellemain, E., J. E. Swenson, and P. Taberlet. Mating strategies in relation to sexually selected infanticide in a non-social carnivore: The brown bear. Ethology 112(3) (2006): 238-246.
  • Brown, G. Great Bear Almanac. New York: Lyons & Buford, 1996. ISBN 1558212108
  • Cameron, W. Learn to identify black bears and grizzly (brown) bears. Mountain Nature 2005.
  • Dewey, T., and L. Ballenger. Ursus arctos. Animal Diversity Web, 2002. Retrieved April 29, 2020.
  • Herrero, S. Bear Attacks: Their Causes and Avoidance, revised edition. Guilford, CT: Lyons Press, 2002. ISBN 158574557X
  • Macdonald, D. The Encyclopedia of Mammals. London: Allen & Unwin, 1984. ISBN 004500028X
  • Matthiessen, P., and M. Hornocker. Tigers In The Snow. North Point Press, 2001. ISBN 0865475962
  • Mazak, V. Der Tiger: Panthera tigris. Nachdruck der 3. Auflage von 1983. Westarp Wissenschaften Hohenwarsleben, 2004. ISBN 3894327596
  • Russian Hunting Agency (RHA). Brown bear hunting in Russia. Russian Hunting Agency, 2007. Retrieved April 29, 2020.
  • Seryodkin, I. V., J. M. Goodrich, A. V. Kostyrya, B. O. Schleyer, E. N. Smirnov, L. L. Kerley, and D. G. Miquelle. "Relationship between tigers, brown bears, and Himalayan black bears." In Tigers of Sikhote-Alin Zapovednik: Ecology and Conservation, edited by D. G. Miquelle, E. N. Smirnov, and J. M. Goodrich, 156-163. Vladivostok, Russia: PSP, 2005.
  • Waits, L. P., S. L. Talbot, R. H. Ward, and G. F. Shields. Mitochondrial DNA phylogeography of the North American brown bear and implications for conservation. Conservation Biology 12(2) (1998): 408-417.
  • Wood, G. L. The Guinness Book of Animal Facts and Feats. Sterling Pub Co., 1983. ISBN 978-0851122359

External links

All links retrieved November 21, 2023.


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