The use of this name is ancient and has been found mentioned in
several rune stone s who believed saying the actual term for "bear"
would summon it. Because peasants avoided saying the original name, it has been
lost to history and "bear" has replaced it. These animals looked very
different from today's bears, being small and raccoon-like in overall
appearance, and diets perhaps more similar to that of a badger. Parictis does not
appear in Eurasia and Africa until the Miocene. Bears are generally bulky and
robust animals with relatively short legs. They are sexually dimorphic with
regard to size, with the males being larger. Larger species tend to show
increased levels of sexual dimorphism in comparison to smaller species, and
where a species varies in size across its distribution; individuals from
larger-sized areas tend also to vary more. Bears are the most massive
terrestrial members of the order Carnivore. The.The smallest bears are the sun bears
of Asia, which weigh an average of 65 kg (143 lb) for the males and 45 kg (99
lb) for the females, though the smallest mature females can weigh only 20 kg
(44 lb).
Bears have an excellent sense of smell, better than the dogs (Canidae),
or possibly any other mammal. This sense of smell is used for signalling
between bears (either to warn off rivals or detect mates) and for finding food.
Smell is the principal sense used by bears to find most of their food. Unlike
most other members of the Carnivore, bears have relatively undeveloped
carnassial teeth, and their teeth are adapted for a diet that includes a
significant amount of vegetable matter. The canine teeth are large, and the
molar teeth flat and crushing. Considerable variation occurs in dental formula
even within a given species. This may indicate bears are still in the process
of evolving from carnivorous to predominantly herbivorous diets. All "medium"-sized bear species
(which include the other five extant species) are around the same average
weight, with males averaging around 100 to 120 kg (220 to 260 lb) and females
averaging around 60 to 85 kg (132 to 187 lb), although it is not uncommon for
male American black bears to considerably exceed "average"
weights.Bears are primarily found in the Northern Hemisphere, and with one
exception, only in Asia, North America and Europe.
A single species, the
spectacled bear, is native to the Andean region of South America. The Atlas
bear, a subspecies of the brown bear, was the only bear native to Africa. It
was distributed in North Africa from Morocco to Libya, but has been extinct
since around the 1870s. The most widespread species is the brown bear, which
occurs from Western Europe eastwards through Asia to the western areas of North
America. While many people think bears are nocturnal, they are, in fact,
generally diurnal, active for the most part during the day. The belief they are
nocturnal apparently comes from the habits of bears that live near humans,
which engage in some nocturnal activities, such as raiding trash cans or crops
while avoiding humans.[citation needed] The sloth bear of Asia is the most
nocturnal of the bears, but this varies by individual, and females with cubs
are often diurnal to avoid competition with males and nocturnal predators.Bears
are overwhelmingly solitary and are considered to be the most asocial of all
the Carnivore. Their carnivorous reputation not withstanding, most bears have
adopted diets of more plant than animal matter and are completely opportunistic
omnivores.
Some bears will climb trees to obtain mast (edible vegetative or
reproductive parts such as acorns); smaller species that are more able to climb
include a greater amount of this in their diets. Such masts can be very
important to the diets of these species, and mast failures may result in
long-range movements by bears looking for alternative food sources. When taking
warm-blooded animals, bears will typically take small or young animals, as they
are easier to catch. However, both species of black bears and the brown bear
can sometimes take large prey, such as ungulates. Often, bears will feed on
other large animals when they encounter a carcass, whether or not the carcass
is claimed by, or is the kill of, another predator. The age at which bears
reach sexual maturity is highly variable, both between and within species.
Sexual maturity is dependent on body condition, which is in turn dependent upon
the food supply available to the growing individual. The females of smaller
species may have young in as little as two years, whereas the larger species
may not rear young until they are four or even 9 years old.
First breeding may
be even later in males, where competition for mates may leave younger males
without access to females. Male bears, especially polar and brown bears will
kill and sometimes devour cubs born to another father to induce a female to
breed again. Female bears are often successful in driving off males in
protection of their cubs, despite being rather smaller. Many bears of northern
regions are assumed [by whom?] to hibernate in the winter, a belief supported
by a number of scientific studies. While many bear species do go into a
physiological state often colloquially called "hibernation" or
"winter sleep", it is not true hibernation. Some species, such as the
polar bear, American black bear, sloth bear, and brown bear, are dangerous to
humans, especially in areas where they have become used to people. All bears
are physically powerful and are likely capable of fatally attacking a person,
but they, for the most part, are shy, are easily frightened and will avoid
humans. Injuries caused by bears are rare, but are often widely reported. Where
bears raid crops or attack livestock, they may come into conflict with humans.
These problems may be the work of only a few bears, but they create a climate
of conflict, as farmers and ranchers may perceive all losses as due to bears
and advocate the preventive removal of all bears.
Mitigation methods may be
used to reduce bear damage to crops, and reduce local antipathy towards bears.
Bears in captivity have been trained to dance, box, or ride bicycles; however,
this use of the animals became controversial in the late 20th century. Bears
were kept for baiting in Europe at least since the 16th century. Bears in captivity
have been trained to dance, box, or ride bicycles; however, this use of the
animals became controversial in the late 20th century. Bears were kept for
baiting in Europe at least since the 16th century."The Brown Bear of
Norway" is a Scottish fairy tale telling the adventures of a girl who
married a prince magically turned into a bear, and who managed to get him back
into a human form by the force of her love and after many trials and
difficulties. In the 1970s, this story was adapted into the East German fantasy
film The Singing Ringing Tree and broadcast on British television. This
recurrent motif was used by the Church as a symbol of the victory of
Christianity over paganism. In the Norse settlements of northern England during
the 10th century, a type of "hogback" grave cover of a long narrow
block of stone, with a shaped apex like the roof beam of a long house, is
carved with a muzzled, thus christianised, bear clasping each gable end.
Two
authoritative organizations for seeking scientific information on bear species
of the world are the International Association for Bear Research &
Management, also known as the International Bear Association (IBA); and the
Bear Specialist Group of the Species Survival Commission, a part of the
International Union for the Conservation of Nature. These organizations focus
on the species' natural history, management, and conservation.
No comments:
Post a Comment