Multiple morphological forms sometimes recognized as subspecies exist, including the mainland grizzly (Ursus arctos horribilis), Kodiak bear (U. a. middendorffi), peninsular grizzly (U. a. gyas), and the recently extinct California grizzly (U. a. californicus†)[1][2] and Mexican grizzly bear (U. a. nelsoni†). On average bears near the coast tend to be larger while inland grizzlies tend to be smaller.
The Ussuri brown bear (U. a. lasiotus) inhabiting Russia, Northern China, Japan and Korea[3][4][5] is sometimes referred to as the black grizzly, although it is a different subspecies from the bears in America.
Classification
Meaning of "grizzly"
Meriwether Lewis and William Clark first described it as grisley, which could be interpreted as either "grizzly" (i.e., "grizzled"—that is, with golden and grey tips of the hair) or "grisly" ("fear-inspiring", now usually "gruesome").[6] The modern spelling supposes the former meaning; even so, naturalist George Ord formally classified it in 1815 as U. horribilis, not for its hair, but for its character.[7]Evolution and genetics
Grizzly phylogenetics
Classification has been revised along genetic lines.[1] There are two morphological forms of Ursus arctos, the grizzly and the coastal brown bears, but these morphological forms do not have distinct mtDNA lineages.[8]Ursus arctos - the brown bear
Brown bears originated in Eurasia and traveled to North America approximately 50,000 years ago,[9][10] spreading into the contiguous United States about 13,000 years ago.[11] In the 19th century, the grizzly was classified as 86 distinct species. However, by 1928 only seven grizzlies remained[2] and by 1953 only one species remained globally.[12] However, modern genetic testing reveals the grizzly to be a subspecies of the brown bear (Ursus arctos). Rausch found that North America has but one species of grizzly.[13] Therefore, everywhere it is the "brown bear"; in North America, it is the "grizzly", but these are all the same species, Ursus arctos.Ursus arctos subspecies in North America
In 1963 Rausch reduced the number of North American subspecies to one, Ursus arctos middendorffi[14]Further testing of Y-chromosomes is required to yield an accurate new taxonomy with different subspecies.[1]
Coastal grizzlies, often referred to by the popular but geographically redundant synonym of "brown bear" or "Alaskan brown bear" are larger and darker than inland grizzlies, which is why they, too, were considered a different species from grizzlies. Kodiak grizzly bears were also at one time considered distinct. Therefore, at one time there were five different "species" of brown bear, including three in North America.[15]
Appearance
Grizzly claws are longer than an American black bear's and adapted for digging
Although variable in color from blond to nearly black, grizzly bear fur is typically brown with darker legs and commonly white or blond tipped fur on the flank and back.[20] A pronounced hump appears on their shoulders; the hump is a good way to distinguish a grizzly bear from a black bear, as black bears do not have this hump. Aside from the distinguishing hump a grizzly bear can be identified by a "dished in" profile of their face with short, rounded ears, whereas a black bear has a straight face profile and longer ears.[21] A grizzly bear can also be identified by its rump, which is lower than its shoulders, while a black bear's rump is higher.[21] A grizzly bear's front claws measure about 2–4 inches in length and a black bear's measure about 1–2 inches in length.[21]
A Grizzly Bear roams in a wooded area near Jasper Townsite in Jasper National Park, Alberta, Canada.
Range and population
Grizzly bear in Katmai National Park with partially eaten salmon – the heads, skin and subcutaneous tissue are eaten to obtain the most fat.
The Alaskan population of 30,000 individuals is the highest population of any province/state in North America. Populations in Alaska are densest along the coast, where food supplies such as salmon are more abundant.[28] The Admiralty Island National Monument protects the densest population—1,600 bears on a 1,600-square mile island.[29]
North America
There are currently about 55,000 wild grizzly bears total located throughout North America, most of which reside in Alaska.[9] Only about 1,500 grizzlies are left in the lower 48 states of the US.[30] Of these, about 800 live in Montana.[31] About 600 more live in Wyoming, in the Yellowstone-Teton area.[32] There are an estimated 70–100 grizzly bears living in northern and eastern Idaho. Its original range included much of the Great Plains and the southwestern states, but it has been extirpated in most of those areas. Combining Canada and the United States, grizzly bears inhabit approximately half the area of their historical range.[9]Although the once-abundant grizzly bear (see California grizzly bear) appears prominently on the state flag of California and was the symbol of the Bear Flag Republic before California's admission to the Union, they are no longer naturally present. The last grizzly in all of California was killed in the Sierra foothills east of Fresno in August 1922.[33]
In September 2007, a hunter produced evidence of one bear in the Selway-Bitterroot Wilderness ecosystem, by killing a male grizzly bear there.[34] In the North Cascades ecosystem of northern Washington, grizzly bear populations are estimated to be fewer than 20 bears. One sighting of a grizzly bear in 2010 has been recorded.[35] There has been no confirmed sighting of a grizzly in Colorado since 1979.[36]
Other provinces and the United States may use a combination of methods for population estimates. Therefore, it is difficult to say precisely what methods were used to produce total population estimates for Canada and North America, as they were likely developed from a variety of studies. The grizzly bear currently has legal protection in Mexico, European countries, some areas of Canada and in the United States. However, it is expected that repopulating its former range will be a slow process, due to a variety of reasons including the bear's slow reproductive habits and the effects of reintroducing such a large animal to areas prized for agriculture and livestock. Competition with other predators and predation on cubs are other possible limiting factors for grizzly bear recovery, though grizzly bears also benefit from scavenged carcasses from predators as an easy food source when other food sources decline.
Biology
Hibernation
Grizzly bears hibernate for 5–7 months each year[37] except where the climate is warm, as the California grizzly did not hibernate.[2] During this time, female grizzly bears give birth to their offspring, who then consume milk from their mother and gain strength for the remainder of the hibernation period.[38] To prepare for hibernation, grizzlies must prepare a den, and consume an immense amount of food as they do not eat during hibernation. Grizzly bears do not defecate or urinate throughout the entire hibernation period. The male grizzly bear's hibernation ends in early to mid-March, while females emerge in April or early May.[39]In preparation for winter, bears can gain approximately 180 kg (400 lb), during a period of hyperphagia, before going into hibernation.[40] The bear often waits for a substantial snowstorm before it enters its den: such behavior lessens the chances predators will find the den. The dens are typically at elevations above 1,800 m (5,900 ft) on north-facing slopes.[41] There is some debate amongst professionals as to whether grizzly bears technically hibernate: much of this debate revolves around body temperature and the ability of the bears to move around during hibernation on occasion. Grizzly bears can "partially" recycle their body wastes during this period.[42] Although inland or Rocky Mountain grizzlies spend nearly half of their life in dens, coastal grizzlies with better access to food sources spend less time in dens. In some areas where food is very plentiful year round, grizzly bears skip hibernation altogether.[43]
Reproduction
Sow with two cubs in the Kananaskis
Grizzly bears have one of the lowest reproductive rates of all terrestrial mammals in North America.[45] This is due to numerous ecological factors. Grizzly bears do not reach sexual maturity until they are at least five years old.[9][46] Once mated with a male in the summer, the female delays embryo implantation until hibernation, during which miscarriage can occur if the female does not receive the proper nutrients and caloric intake.[47] On average, females produce two cubs in a litter[46] and the mother cares for the cubs for up to two years, during which the mother will not mate.[9]
Mother grizzly with a cub
Litter size is between one and four cubs, averaging twins or triplets. Cubs are always born in the mother's winter den while she is in hibernation. Female grizzlies are fiercely protective of their cubs, being able to fend off predators as large as male bears bigger than they are in defence of the cubs.[49] Cubs feed entirely on their mother's milk until summer comes, after which they still drink milk but begin to eat solid foods. Cubs gain weight rapidly during their time with the mother—their weight will have ballooned from 4.5 to 45 kg (10 to 99 lb) in the two years spent with the mother. Mothers may see their cubs in later years but both avoid each other.[50]
Longevity
The average lifespan for a male is estimated at 22 years, with that of a female being slightly longer at 26.[51] Females live longer than males due to their less dangerous life; they do not engage in seasonal breeding fights as males do. The oldest wild inland grizzly was 34 years old in Alaska; the oldest coastal bear was 39,[52] but most grizzlies die in their first few years of life from predation or hunting.[53] Captive grizzlies have lived as long as 44 years.[citation needed]Ecology
Diet
Although grizzlies are of the order Carnivora and have the digestive system of carnivores, they are normally omnivores: their diets consist of both plants and animals. They have been known to prey on large mammals, when available, such as moose, elk, caribou, white-tailed deer, mule deer, bighorn sheep, bison, and even black bears; though they are more likely to take calves and injured individuals rather than healthy adults. Grizzly bears feed on fish such as salmon, trout, and bass, and those with access to a more protein-enriched diet in coastal areas potentially grow larger than inland individuals. Grizzly bears also readily scavenge food or carrion left behind by other animals.[54] Grizzly bears will also eat birds and their eggs, and gather in large numbers at fishing sites to feed on spawning salmon. They frequently prey on baby deer left in the grass, and occasionally they raid the nests of raptors such as bald eagles.[55]Canadian or Alaskan grizzlies are larger than those that reside in the American Rocky Mountains. This is due, in part, to the richness of their diets. In Yellowstone National Park in the United States, the grizzly bear's diet consists mostly of whitebark pine nuts, tubers, grasses, various rodents, army cutworm moths, and scavenged carcasses.[56] None of these, however, match the fat content of the salmon available in Alaska and British Columbia. With the high fat content of salmon, it is not uncommon to encounter grizzlies in Alaska weighing 540 kg (1,200 lb).[57] Grizzlies in Alaska supplement their diet of salmon and clams with sedge grass and berries. In areas where salmon are forced to leap waterfalls, grizzlies gather at the base of the falls to feed on and catch the fish. Salmon are at a disadvantage when they leap waterfalls because they cluster together at their bases and are therefore easier targets for the grizzlies.[58] Grizzly bears are well-documented catching leaping salmon in their mouths at Brooks Falls in Katmai National Park and Preserve in Alaska. They are also very experienced in chasing the fish around and pinning them with their claws.[59][60] At such sites such as Brooks Falls and McNeil Falls in Alaska, big male grizzlies fight regularly for the best fishing spots.[61] Grizzly bears along the coast also forage for razor clams, and frequently dig into the sand to seek them.[62] During the spring and fall, directly before and after the salmon runs, berries and grass make up the mainstay of the diets of coastal grizzlies.[63]
Grizzly bear fishing for salmon at Brooks Falls, Alaska
Meat, as already described, is an important part of a grizzly's diet. Grizzly bears occasionally prey on small mammals, such as marmots, ground squirrels, lemmings, and voles.[66] The most famous example of such predation is in Denali National Park and Preserve, where grizzlies chase, pounce on, and dig up Arctic ground squirrels to eat.[67] In some areas, grizzly bears prey on hoary marmots, overturning rocks to reach them, and in some cases preying on them when they are in hibernation.[68] Larger prey includes bison and moose, which are sometimes taken by bears in Yellowstone National Park. Because bison and moose are dangerous prey, grizzlies usually use cover to stalk them and/or pick off weak individuals or calves.[69][70] Grizzlies in Alaska also regularly prey on moose calves, which in Denali National Park may be their main source of meat. In fact, grizzly bears are such important predators of moose and elk calves in Alaska and in Yellowstone, that they may kill as many as 51 percent of elk or moose calves born that year. Grizzly bears have also been blamed in the decline of elk in Yellowstone National Park when the actual predators were thought to be gray wolves.[71][72][73][74][75] In northern Alaska, grizzlies are a significant predator of caribou, mostly taking sick or old individuals or calves.[76] Several studies show that grizzly bears may follow the caribou herds year-round in order to maintain their food supply.[77][78] In northern Alaska, grizzly bears often encounter muskox. Despite the fact that muskox do not usually occur in grizzly habitat and that they are bigger and more powerful than caribou, predation on muskox by grizzlies has been recorded.[79]
Grizzly bears along the Alaskan coast also scavenge on dead or washed up whales.[80] Usually such incidents involve only one or two grizzlies at a carcass, but up to ten large males have been seen at a time eating a dead humpback whale. Dead seals and sea lions are also consumed.[citation needed]
Although the diets of grizzly bears vary extensively based on seasonal and regional changes, plants make up a large portion of them, with some estimates as high as 80–90%.[81] Various berries constitute an important food source when they are available. These can include blueberries, blackberries (Rubus fruticosus), salmon berries (Rubus spectabilis), cranberries (Vaccinium oxycoccos), buffalo berries (Shepherdia argentea), soapberries (Shepherdia canadensis), and huckleberries (Vaccinium parvifolium), depending on the environment. Insects such as ladybugs, ants, and bees are eaten if they are available in large quantities. In Yellowstone National Park, grizzly bears may obtain half of their yearly caloric needs by feeding on miller moths that congregate on mountain slopes.[82] When food is abundant, grizzly bears will feed in groups. For example, many grizzly bears will visit meadows right after an avalanche or glacier slide. This is due to an influx of legumes, such as Hedysarum, which the grizzlies consume in massive amounts.[83] When food sources become scarcer, however, they separate once again.
Interspecific competition
Grizzly bear cub in Western Canada
Black bears generally stay out of grizzly territory, but grizzlies may occasionally enter black bear terrain to obtain food sources both bears enjoy, such as pine nuts, acorns, mushrooms, and berries. When a black bear sees a grizzly coming, it either turns tail and runs or climbs a tree. Black bears are not strong competition for prey because they have a more herbivorous diet. Confrontations are rare because of the differences in size, habitats, and diets of the bear species. When this happens, it is usually with the grizzly being the aggressor. The black bear will only fight when it is a smaller grizzly such as a yearling or when the black bear has no other choice but to defend itself. There is at least one confirmed observation of a grizzly bear digging out, killing and eating a black bear when the latter was in hibernation.[89]
The segregation of black bear and grizzly bear populations is possibly due to competitive exclusion. In certain areas, grizzly bears outcompete black bears for the same resources.[90] For example, many Pacific coastal islands off British Columbia and Alaska support either the black bear or the grizzly, but rarely both.[91] In regions where both species coexist, they are divided by landscape gradients such as age of forest, elevation and openness of land. Grizzly bears tend to favor old forests with high productivity, higher elevations and more open habitats compared with black bears.[90]
The relationship between grizzly bears and other predators is mostly one-sided; grizzly bears will approach feeding predators to steal their kill. In general, the other species will leave the carcasses for the bear to avoid competition or predation. Any parts of the carcass left uneaten are scavenged by smaller animals.[92] Cougars generally give the bears a wide berth. Grizzlies have less competition with cougars than with other predators, such as coyotes, wolves, and other bears. When a grizzly descends on a cougar feeding on its kill, the cougar usually gives way to the bear. When a cougar does stand its ground, it will use its superior agility and its claws to harass the bear, yet stay out of its reach until one of them gives up. Grizzly bears occasionally kill cougars in disputes over kills.[93] There have been several accounts, primarily from the late 19th and early 20th centuries, of cougars and grizzly bears killing each other in fights to the death.[94] The other big cat that is present in the United States, which may pose as a threat to bears, is the jaguar.[95]
Coyotes, foxes, and wolverines are generally regarded as pests to the grizzlies rather than competition, though they may compete for smaller prey, such as ground squirrels and rabbits. All three will try to scavenge whatever they can from the bears. Wolverines are aggressive enough to occasionally persist until the bear finishes eating, leaving more scraps than normal for the smaller animal.[92] Packs of coyotes have also displaced grizzly bears in disputes over kills.[96]
Ecological role
The grizzly bear has several relationships with its ecosystem. One such relationship is a mutualistic relationship with fleshy-fruit bearing plants. After the grizzly consumes the fruit, the seeds are excreted and thereby dispersed in a germinable condition. Some studies have shown germination success is indeed increased as a result of seeds being deposited along with nutrients in feces.[97] This makes grizzly bears important seed distributors in their habitats.[98]While foraging for tree roots, plant bulbs, or ground squirrels, bears stir up the soil. This process not only helps grizzlies access their food, but also increases species richness in alpine ecosystems.[99] An area that contains both bear digs and undisturbed land has greater plant diversity than an area that contains just undisturbed land.[99] Along with increasing species richness, soil disturbance causes nitrogen to be dug up from lower soil layers, and makes nitrogen more readily available in the environment. An area that has been dug by the grizzly bear has significantly more nitrogen than an undisturbed area.[100]
Nitrogen cycling is not only facilitated by grizzlies digging for food, it is also accomplished via their habit of carrying salmon carcasses into surrounding forests.[101] It has been found that spruce tree (Picea glauca) foliage within 500 m (1,600 ft) of the stream where the salmon have been obtained contains nitrogen originating from salmon on which the bears preyed.[102] These nitrogen influxes to the forest are directly related to the presence of grizzly bears and salmon.[103]
Grizzlies directly regulate prey populations and also help prevent overgrazing in forests by controlling the populations of other species in the food chain.[104] An experiment in Grand Teton National Park in Wyoming in the United States showed removal of wolves and grizzly bears caused populations of their herbivorous prey to increase.[105] This, in turn, changed the structure and density of plants in the area, which decreased the population sizes of migratory birds.[105] This provides evidence grizzly bears represent a keystone predator, having a major influence on the entire ecosystem they inhabit.[104]
When grizzly bears fish for salmon along the coasts of Alaska and British Columbia, they often only eat the skin, brain and roe of the fish. In doing so, they provide a food source for gulls, ravens, and foxes, all of which eat salmon as well; this benefits both the bear and the smaller predators.[106]
Interaction with humans
Conflicts with humans
Native Americans fighting a Grizzly Bear, painting by George Catlin.
A rough and tumble with a grizzly by H. Bullock Webster, watercolor
Grizzly bears normally avoid contact with people. In spite of their obvious physical advantage they rarely actively hunt humans.[110] Most grizzly bear attacks result from a bear that has been surprised at very close range, especially if it has a supply of food to protect, or female grizzlies protecting their offspring.[111] A bear killing a human in a national park may be killed to prevent its attacking again.[112]
Hugh Glass being attacked by a grizzly bear, from an early newspaper illustration of unknown origin
Increased human–bear interaction has created "problem bears": bears adapted to human activities or habitat.[113] Aversive conditioning using rubber bullets, foul-tasting chemicals, or acoustic deterrent devices attempt to condition bears to associate humans with unpleasantness, but is ineffectual when bears have already learned to positively associate humans with food.[114] Such bears are translocated or killed because they pose a threat to humans. The B.C. government kills approximately 50 problem bears each year[114] and overall spends more than one million dollars annually to address bear complaints, relocate bears and kill them.[114]
Bear awareness programs have been developed by numerous towns in British Columbia, Canada, to help prevent conflicts with both black and grizzly bears. The main premise of these programs is to teach humans to manage foods that attract bears. Keeping garbage securely stored, harvesting fruit when ripe, securing livestock behind electric fences, and storing pet food indoors are all measures promoted by bear awareness programs. The fact that grizzly bears are less numerous and even protected in some areas, means that preventing conflict with grizzlies is especially important. Revelstoke, British Columbia is a community that demonstrates the success of this approach. In the ten years preceding the development of a community education program in Revelstoke, 16 grizzlies were destroyed and a further 107 were relocated away from the town. An education program run by Revelstoke Bear Aware was put in place in 1996. Since the program began just four grizzlies have been eliminated and five have been relocated.[115]
For back-country campers, hanging food between trees at a height unreachable to bears is a common procedure, although some grizzlies can climb and reach hanging food in other ways. An alternative to hanging food is to use a bear canister.[116]
Traveling in groups of six or more can significantly reduce the chance of bear-related injuries while hiking in bear country.[117]
Grizzly bears are especially dangerous because of the force of their bite, which has been measured at over 8 megapascals (1160 psi). It has been estimated that a bite from a grizzly could even crush a bowling ball.[118]
Protection
A grizzly in Denali National Park
Within the United States, the U.S. Fish and Wildlife Service concentrates its effort to restore grizzly bears in six recovery areas. These are Northern Continental Divide (Montana), Yellowstone (Montana, Wyoming, and Idaho), Cabinet-Yaak (Montana and Idaho), Selway-Bitterroot (Montana and Idaho), Selkirk (Idaho and Washington), and North Cascades (Washington). The grizzly population in these areas is estimated at 750 in the Northern Continental Divide, 550 in Yellowstone, 40 in the Yaak portion of the Cabinet-Yaak, and 15 in the Cabinet portion (in northwestern Montana), 105 in Selkirk region of Idaho, 10–20 in the North Cascades, and none currently in Selway-Bitterroots, although there have been sightings.[122] These are estimates because bears move in and out of these areas, and it is therefore impossible to conduct a precise count. In the recovery areas that adjoin Canada, bears also move back and forth across the international boundary.
The U.S. Fish and Wildlife Service claims the Cabinet-Yaak and Selkirk areas are linked through British Columbia, a claim that is disputed.[123] U.S. and Canadian national parks, such as Banff National Park, Yellowstone and Grand Teton, and Theodore Roosevelt National Park are subject to laws and regulations designed to protect the bears.
A sign at a BC Park warns campers to hang food, garbage, and toiletries out of reach of bears, or to use a secure bear cache.
Farther north, in Alberta, Canada, intense DNA hair-snagging studies in 2000 showed the grizzly population to be increasing faster than what it was formerly believed to be, and Alberta Sustainable Resource Development calculated a population of 841 bears.[129] In 2002, the Endangered Species Conservation Committee recommended that the Alberta grizzly bear population be designated as threatened due to recent estimates of grizzly bear mortality rates that indicated the population was in decline. A recovery plan released by the provincial government in March 2008 indicated the grizzly population is lower than previously believed.[130] In 2010, the provincial government formally listed its population of about 700 grizzlies as "Threatened".[131]
Environment Canada consider the grizzly bear to a "special concern" species, as it is particularly sensitive to human activities and natural threats. In Alberta and British Columbia, the species is considered to be at risk.[132] In 2008, it was estimated there were 16,014 grizzly bears in the British Columbia population, which was lower than previously estimated due to refinements in the population model.[133]
The Mexican grizzly bear (Ursus arctos nelsoni) is extinct.[134][135]
Conservation efforts
Drum or barrel trap, used to safely relocate bears, adjacent to a building in Grand Teton National Park in Wyoming, United States
The Refuge for Endangered Wildlife located on Grouse Mountain in Vancouver is an example of a different type of conservation effort for the diminishing grizzly bear population. The refuge is a five-acre terrain which has functioned as a home for two orphaned grizzly bears since 2001.[137] The purpose of this refuge is to provide awareness and education to the public about grizzly bears, as well as providing an area for research and observation of this secluded species.
Another factor currently being taken into consideration when designing conservation plans for future generations are anthropogenic barriers in the form of urban development and roads. These elements are acting as obstacles, causing fragmentation of the remaining grizzly bear population habitat and prevention of gene flow between subpopulations (for example, Banff National Park). This, in turn, is creating a decline in genetic diversity, and therefore the overall fitness of the general population is lowered.[138] In light of these issues, conservation plans often include migration corridors by way of long strips of "park forest" to connect less developed areas, or by way of tunnels and overpasses over busy roads.[139] Using GPS collar tracking, scientists can study whether or not these efforts are actually making a positive contribution towards resolving the problem.[140] To date, most corridors are found to be infrequently used, and thus genetic isolation is currently occurring, which can result in inbreeding and therefore an increased frequency of deleterious genes through genetic drift.[141] Current data suggest female grizzly bears are disproportionately less likely than males to use these corridors, which can prevent mate access and decrease the number of offspring.
In the United States, national efforts have been made since 1982 for the recovery plan of grizzly bears.[142] A lot of the efforts made have been through different organizations efforts to educate the public on grizzly bear safety, habits of grizzly bears and different ways to reduce human-bear conflict. The Interagency Grizzly Bear Recovery Committee is one of many organizations committed to the recovery of grizzly bears in the lower 48 states.[143] There are five recovery zones for grizzly bears in the lower 48 states including the North Cascades ecosystem in Washington state.[144] The National Park Service and U.S. Fish and Wildlife initiated the process of an environmental impact statement that started in the fall of 2014 to begin the recovery process of grizzly bears to the North Cascades region.[144] A final plan and environmental impact statement was released in the spring of 2017 with a record of decision to follow.[144][145]
In early March 2016, the U.S. Fish and Wildlife Service proposed to withdraw Endangered Species Act protections from grizzly bears in and around Yellowstone National Park. The population has risen from 136 bears in 1975 to an estimated 700 in 2017, and was "delisted" in June 2017.[144][146][145]
Bear-watching
In the past 20 years in Alaska, ecotourism has boomed. While many people come to Alaska to bear-hunt, the majority come to watch the bears and observe their habits. Some of the best bear viewing in the world occurs on coastal areas of the Alaska Peninsula, including in Lake Clark National Park and Preserve, Katmai National Park and Preserve, and the McNeil River State Game Sanctuary and Refuge. Here bears gather in large numbers to feast on concentrated food sources, including sedges in the salt marshes, clams in the nearby tidal flats, salmon in the estuary streams, and berries on the neighboring hillsides.
Bear catches a salmon at Brooks Falls
The McNeil River State Game Sanctuary and Refuge, on the McNeil River, is home to the greatest concentration of brown bears in the world. An estimated 144 individual bears have been identified at the falls in a single summer with as many as 74 at one time;[151] 60 or more bears at the falls is a frequent sight, and it is not uncommon to see 100 bears at the falls throughout a single day.[152] The McNeil River State Game Refuge, containing Chenik Lake and a smaller number of grizzly bears, has been closed to grizzly hunting since 1995.[153] All of the Katmai-McNeil area is closed to hunting except for Katmai National Preserve, where regulated legal hunting takes place.[154] In all, the Katmai-McNeil area has an estimated 2,500 grizzly bears.[155]
Admiralty Island, in southeast Alaska, was known to early natives as Xootsnoowú, meaning "fortress of bears," and is home to the densest grizzly population in North America. An estimated 1600 grizzlies live on the island, which itself is only 140 km (90 mi) long.[156] One place to view grizzly bears in the island is probably Pack Creek, in the Stan Price State Wildlife Sanctuary. 20 to 30 grizzlies can be observed at the creek at one time and like Brooks Camp, visitors can watch bears from an above platform.[157] Kodiak Island, hence its name, is another place to view bears. An estimated 3,500 Kodiak grizzly bears inhabit the island, 2,300 of these in the Kodiak National Wildlife Refuge.[158][159] The O'Malley River is considered the best place on Kodiak Island to view grizzly bears.[160]
Ursus arctos
(Linnaeus, 1758
Historic and present range
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.