Реферат на тему Tigers Essay Research Paper Tigers are descended
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Tigers Essay, Research Paper
Tigers are descended from civet-like animals called niacis that lived during the age
of the dinosaurs about 60 million years ago (Dang, 1994). These small mammals, with
long bodies and short flexible limbs, evolved over millions of years into several hundred
different species, including cats, bears, dogs and weasels. About 37 cat species exist today
(Dang, 1994). Tigers evolved in eastern Asia , but it is not exact. Sabre-tooth tigers are
not the ancestors of today’s tigers. In fact, sabre-tooth tigers belonged to a separate
branch of cat evolution which became extinct many millions of years ago.
The Siberian or Amur tiger lives primarily in eastern Russia, and a few are found in
northeastern China and northern North Korea. It is estimated that 437-506 Siberian tigers
still exist in the wild (Tilson ,1995). About 490 captive Siberian tigers a re managed in
zoo conservation programs (Tilson, 1995).
The South China tiger is the most critically endnagered of all tiger subspecies.
They are found in central and eastern China. It is estimated that only 20-30 South China
tigers are left in the wild (Dang ,1994). Currently 48 South China tigers live in 19 zoos,
all in China (Dang ,1994).
The distribution of the Indochinese tiger is centered in Thailand, and is found in
Myanmar, southern China, CAnbodia, Laos, Vietnam, and penisular Malaysia. About
1,180- 1,790 Indochines tigers are left in the wild and about 60 live in zoos (Tilson, 1995).
Bengal tigers live in India, and some range through Nepal, Bangladesh, Bhutan,
and Myanmar. The estimated wild population is approzimately 3,060- 4,735 tigers, with
about 333 in captivity, primarily in zoos in India (Dang, 1994).
White tigers are just white-colored Bengal tigers. They ae not a separate
subspecies of tiger, and they are no albinos. They have blue eyes, a pink nose, and creamy
white fur with chocolate colored striipes, White tigers are only born when two tigers that
both carry the unusual gene for white coloring mate, Wild white tigers are very rare, and
todayt they can only be seen in zoos.
The Sumatrain tiger is found only on the Indonesian island of Sumatra. About
400-500 wild Sumatran tigers are believed to exist, primarily inthe island’s five national
parks (Dang, 1994). Another 235 Simatran tigers live in zoos around the world (Dang,
1994).
Three tiger subspecies have been considered to become extinct in the past 70 years
(Tilson ,1994). The Caspian tiger, known as the Panthera tigris virgata, once ranged in
Afghanistan, Iran, Turkey, Mongolia, and Central Asiatic area of Russia and probably
went extinct in the 1950’s (Tilson, 1995). The Javan tiger, Panthera tigris sondaica,
formerly ranged on the Indonesian island of Java and was last seen in 1972 (Tilson, 1995).
The Bali tiger, Panthera tigris balica, once lived on Bali, where the last tiger was believed
to have been killed in 1937 (Tilson, 1995).
Tigers have social behavior. Adult tigers are solitary animal that establish their
territories in areas with enough prey, cover and water to support them. The hardship of
loating prey in tiger habitat makes it more efficient for tigers to hunt alone. As a result,
they do not tend to form social groups like lions. A female tiger and her cubs are the
exception to this, and will form a family group for 2 to 3 years, until the cubs are able to
fend for themselves (Dang ,1994). The territory of a tiger usually ranges in size from
about 10 to 30 square miles, although the territory of a Siberian tiger may be as large as
120 square miles (Tilson, 1995). Both male and female tigers spray bushes and trees
along their route with amixture of urine and scent gland secretions. This is a way of
declaring their territory. They also leave marks on trees, and urinate or leave droppongs
in prominent places.
Female tigers reach maturity when they area bout 3 years old and males reach it
when they are a year or so later (Dang, 1994). In temperate climates, a tigress comes into
heat only seasonally , but in tropical climates, she may come int heat throughtout the year.
She signals her readiness with scent marking and locating roars. The brief act of
copulaiton occurs continually for a five day period. Tigers are induced ovulators, and
must be stimualted through frequent copulation in order to become pregnant. To
stimulate ovulation the male tiger’s penis has spines. This explains in part why the female
roars and lashes out at the male immediately following copulation.
After mating, the period for tigers is about 103 days (Tilson, 1995). The average
litter size of tigers is 2 or 3 cubs (Tilson, 1995). One usually dies at birth. Tiger cubs are
born blind and weigh only about 2 to 3 pounds (Tilson, 1995). They live on their mother’s
milk for 6-8 weeks before the female begins taking them to kill in order to feed (Tilson,
1995). They start making their kills within 18 months of age (Tilson, 1995). Young tigers
leave their mother’s range at anywhere from a year and a half to three years of age,
depending on whether the mother has another liter. Females tend to stay closer to the
mother’s range than males.
Over much of the tiger’s broad geographic range, wild pig, wild cattle and several
species of deer are its major prey. All prey are forest or grassland ungulates that range in
size from 65 to 2,000 pounds (Tilson, 1995). Tigers are ambush hunters, stalking their
prey, appproaching as closely as possible. When they are close enough they charge the
animal. They bite the neck or throat of their prey. The neck bite, which affects the spinal
cord, is typically used on small or medium sized prey. The throat bite that causes
suffocation is used on larger animals. After killing their prey, tigers drag the animal to a
safe place so that no one else eats it. They usually carry their prey in high trees.
Typically, wild tigers go wild on fresh kills, and can eat as much as 40 pounds of meat at
one time (Dang, 1994). Several days may pass before they are hungry enough to hunt
again.
Although tiger attacks on humans are unusual, they do sometimes occur. Because
the Asian human population is increasing, farmers and loggers are beginning to use areas
where tigers live. This causes increasing conflicts between tigers and human. It is thought
that most tigers who eat humans are sick or injured and unanble to kill their prey. Once
they have acquired a taste for human beings, they will keep eating humans. While man-
eating tigers are a rarity in most parts of Asia, they are common in the Sunderbans. No
one lives in the magrove forests and swamps of the Sunderbans. The Sunderban tigers
seem to have targeted humans as prey, and human being attacked are being reported every
year. Several different have been used to combat man-eating tigers in the Sunderbans.
One method uses human dummies fitted with electric wires from car batteries. This
method administers a shock when touched by a tiger. Another method uses a simple mask
of a human face which arw worn on back of your head. This effectively made both sides
of the wearer appear to be the front. This method is used because tigers usually attack
from the behind. While this method seemed to work for several years, the Sunderban
tigers have discovered the trick.
In no further discussion, tigers are very interesting to learn about. Tigers may be
dangerous if you invade their territory. Tigers can be found in open areas and zoos . If
you want to see tigers you should go to a zoo. Tigers are becoming extinct because we
are invading their territories and we should protect them from going extinct because they
are fascinating creatures.