Brown
Bear |
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Brown Bear
rearing |
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Scientific classification |
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Binomial name |
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Ursus
arctos |
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Ursus arctos range map. |
The brown
bear (Ursus arctos) is a species of bear distributed throughout the
Northern hemisphere. Weighing up to 130–700 kg (290-1,550 pounds), the larger
races of brown bear tie with the Polar bear as the largest extant land
carnivores. The grizzly bear (Ursus arctos horribilis), the Kodiak Bear
(Ursus arctos middendorffi), and the Mexican brown bear are North
American subspecies of the brown bear. However, 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.[2]
It is sometimes referred to poetically as the bruin.
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. Brown bears have a large hump
of muscle over their shoulders, which give strength to the forelimbs for
digging. Bears are very powerful, even if considered pound for pound, a big
specimen can break a neck or spine of a fully grown buffalo with a single blow.
Forearms end in massive paws with very powerful claws up to 15 cm (5.9 inches)
in length. Their heads are large and round with a concave facial profile. 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 59
inches), although the abnormally large specimens exceed these measurements. The
smallest subspecies is the European brown bear, with mature females weighing as
little as 90 kg (200 lb). The largest subspecies of the brown bear are the
Kodiak bear and the bears from coastal Russia and Alaska. Some large male
Kodiak are over 3m (10 feet) in height while on their hind legs, and weigh
about 680 kg (1,500 lb). Bears raised in zoos are usually heavier than bears
raised in the wild because of regular feeding and less movement. In zoos, bears
may weigh up to 900 kilograms (2000 pounds), like the well-known
"Goliath" from New Jersey's Space Farms zoo. They have a very short,
stubby tail, just like all bears.
Claws are mainly used for
digging. Unlike the claws of other large predatory animals such as lions or
tigers, brown bear claws are not retractable, giving them a dull edge compared
to the claws of other predators. When hunting, the brown bear uses its sharp
canine teeth for neck-biting its prey. Brown bears, like tigers, ambush their
prey.
In spite of their size,
some have been clocked at speeds in excess of 56 km/h (35 mph). Along with
their strength and deceptive speed, brown bears are legendary for their
stamina. They are capable of running at full speed for miles at a time without
stopping.
Brown bears were once
native to Asia, the Atlas Mountains in Africa, Europe and North America,[3]
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.
Brown bears live in Alaska,
east through the Yukon and Northwest Territories, south through British
Columbia and through the western half of Alberta. Isolated populations exist in
northwestern Washington, northern Idaho, western Montana, and northwestern Wyoming.
Ursus arctos 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, also known as the bulldog bear, was the dominant carnivore at
the time. The giant short-faced bear was a tall, thin animal adapted to eat
large mammals, whereas the grizzly or brown bear has teeth appropriate for its
omnivorous diet. The giant short-faced bear, on average, weighed twice as much
as the grizzly, despite some exceptional grizzly bears in the later Old West
that weighed 800 kilograms.
Ursus arctos 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 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 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 a human
presence in America in unknown, but largest known immigration was that of the
Paleo Indians at about the last ice age, bringing with them the Clovis point
and advanced hunting techniques.
In Europe, the brown bear
outlasted the larger and closely related cave bear. The cave bear was hunted by
Neanderthals 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 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.
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. Much smaller
populations, ranging in the hundreds, are also present in countries such as
Mexico. In Europe, there are 14,000 brown bears in ten separate fragmented
populations, from Spain to Russia and from Scandinavia in the north to Romania
and Bulgaria in the south. They are extinct in the British Isles, extremely
threatened or extinct in France, 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.
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.
Brown bears prefer
semi-open country, usually in mountainous areas.
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" 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.
They are omnivores and feed
on a variety of plant parts, including berries, roots, and sprouts, fungi,
fish, insects, and small mammals, especially ground squirrels. Contrary to
popular mythology, brown bears are not particularly carnivorous as they derive
up to 90% of their dietary food energy from vegetable matter.[citation
needed] Their jaw structure has evolved to fit their dietary habits
and it is longer and lacks strong, sharp canine teeth of true predators. Bears
eat an enormous number of moths during the summer, sometimes as many as 40,000
in a day[1], and may derive up to a third of their food energy from these
insects[2]. 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 (Odocoeilus spp.; Dama spp., Capreolus spp.), Red
Deer (Cervus elaphus or American elk), moose (Alces alces) and
American bison (Bison bison). When brown bears attack these animals,
they tend to choose young calves or aged, sick adults because they are slow and
weak. Brown bears retrace their own tracks and walk only on rocks while being
hunted to avoid being traced.
The brown bear is
plantigrade like all bears, meaning it walks with its entire foot like a human,
rather than on its toes like cats and dogs, which are digitigrade. They can
stand up on their hind legs for extended periods of time. Bears tend to sit
down on their rear with their upper body off the ground.
Normally a solitary animal,
the brown bear congregates alongside streams and rivers during the salmon spawn
in the fall. Every other year, females produce one to four young, which weigh
only about 1 to 2 kg (2 to 5 lb) at birth. Raised entirely by their mother,
cubs are taught to climb trees when in danger. Brown bears are also found in
the midwest region of the U.S. in the states of Montana, Wyoming, Minnesota,
Wisconsin,and Idaho.
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. The saying, "a fed bear is a dead bear," has
come into use to popularize the idea that allowing bears to scavenge human
garbage, pet food, or other food sources that draw the bear into contact with
humans can result in a bear's death.
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."[4]
Some bears become hooked on
a given food source and will return to the same location despite relocation.
Bears that repeatedly return to a human environment for food are sometimes
killed to prevent human injury.
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.
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 sizeable tracts of land. As bears reclaim parts of
their range, they may take livestock as a means of survival. The shepherd is
forced to shoot the bear to protect his livelihood.
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. The
subspecies of brown bears have been listed as follows:[5] 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.[2]
It is extremely rare that
brown bears kill or seriously injure humans, but fatal encounters occur when
brown bears behave aggressively. There are an average of two fatal attacks a
year in North America.[6] In Scandinavia, there are only three known
cases during the last 100 years in which humans were killed by bears. Attacks
usually occur because the bear is injured or a human encounters a mother bear
with cubs. 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 Scandinavian Bear
Research project lists the following situations as potentially dangerous:
1.
Meeting
an injured bear
2.
A
human suddenly appearing
3.
Meeting
a bear in its cave
4.
Meeting
a bear who has been provoked
Anyone walking in a forest
where there are bears should carry an air horn because 'bear bells' tend to
provoke a bear's curiosity and a brown bear's natural instinct is to run away
from humans. When traveling in groups, trail songs are also effective. If
camping, do not bring food into the tent, and clean up all garbage. Bears have
a fantastic sense of smell and will eat anything people eat. If one meets a
bear, one should remain calm and slowly walk in the opposite direction. Running
humans trigger the bear's chasing instinct and bears can outrun humans. Do not
make threatening moves, eye contact, or shout. Thousands of encounters occur
between humans and brown bears every year without conflict.
If a brown bear attacks and
it is impossible to get away, the person should lie down in a fetal position
and put his/her hands around the head to protect from bites to reduce damage to
vital organs. Pretending to be dead may save you. Unlike with the American
black bear, punching or gouging attacking brown bears intensifies their
assaults. [citation needed] Black bears are NOT the same as
Grizzlies. Don't confuse the two.
American black bears,
rarely attack and are almost totally vegetarian, but require a different
technique. For these, people should huddle if in a group or raise hands or
backpack in the air to appear bigger, as well as make lots of noise. There is a
good chance of scaring away a black bear as they are shy and timid. If it
attacks anyway, fight back. Black bears will disengage if injured. However, the
best defense is to make plenty of noise in areas with bears to scare them away
before an encounter.
In some areas, it is
permissible to carry firearms to defend against bear attacks. This includes
most of the state of Alaska and the Canadian bush. In parts of northern Canada,
a rifle of sufficient power is required equipment. The Alaska Department of Fish
and Game recommends as a minimum firearm for use against brown bear a rifle in
the .30-06 range firing 200 grain expanding bullets moving at least 2,000 feet
per second (610 m/s) at impact. Many Alaskan hikers prefer using shotguns
firing a Brenneke slug at magnum velocities or lever-action rifles able to fire
magnum-level .45-70 cartridges. These firearms are lighter and easier to tote
than a full-size bolt-action hunting rifle, but can fire heavy hardcast slugs
which impact with 3,000 ft·lbf or more at close range. They are less effective
in hunting brown bears due to limited effective range, but for purposes of
defense that is not of paramount concern.
It is also important to
remember that the considerations while hunting a brown bear are different from
those which arise while defending against an attacking brown bear. Hunters will
wait for a broadside shot at the heart/lung area of unsuspecting bears. With
proper placement, almost any rifle is capable of taking out a brown bear in
these circumstances. Though it is not recommended and may be illegal under
current game rules, historically the .30-30 and even .32-20 were used to hunt
brown bears. However, when the bear is charging, a round of substantially more
power is preferred to both disable the animal quickly and penetrate the thick
layers of bone, fat, and tissue between the bear's head and shoulders and its
vital organs. Hitting the brain is notoriously difficult due to its placement
deep below a muscular brow.
In the past decade, a
number of high-powered handguns have been produced in the United States for use
in handgun hunting and bear defense. These include the .454 Casull revolvers
produced by Taurus and Ruger and the .500 Smith & Wesson produced for that
company's supersized "X" frame revolver. Their enormous recoil and
weight make them difficult to deploy quickly in the field. Their utility in
defense against brown bears is still a matter of great controversy.
A number of pepper sprays
have recently been developed as non-lethal (but very harmful) and potentially
safer defense against bear attacks. Pepper spray is deployed in the same manner
one would deploy a can of mace; an effective shot is one to the face. Pepper
spray is not used like insect repellant; spraying campsites with pepper spray seems
to attract bears.
Wikipedia
http://en.wikipedia.org/w/index.php?title=Brown_Bear&action=history