Science Fair Project Encyclopedia
Tigers (Panthera tigris) are mammals of the Felidae family, one of four "big cats" that belong to the Panthera genus. Tigers are predatory carnivores.
Most tigers live in forests and grasslands (for which their camouflage is ideally suited). Of all the big cats, only the tiger and jaguar are strong swimmers, and tigers may often be found bathing in ponds, lakes and rivers. Tigers hunt alone, and their diet consists primarily of medium-sized herbivores such as deer, wild pigs, elk and buffalo, but they will also take larger or smaller prey if the circumstances demand it. Humans are probably the tiger's only predator, often illegally killing tigers for their fur or their penises, falsely believed to be aphrodisiacs. From the destruction of its habitat, to the poaching for the fur, tigers have decreased in size and have been placed in the endangered species list. Other than the human, the tiger is at the top of the food chain. A tiger's head often carries the symbol of Wang (king).
Different subspecies of tiger have somewhat different characteristics. In general, male tigers may weigh between 150 and 310 kilograms (330 lb and 680 lb) and females between 100 and 160 kg (220 lb and 350 lb). The males are between 2.6 and 3.3 metres (8'6" and 10'9") in length, and the females are between 2.3 and 2.75 metres (7'6" and 9') in length. Of the more common subspecies, Corbetts Tigers are the smallest and Amur Tigers the largest.
The ground of the coat may be any colour from yellow to orange/red, with white areas on the chest, neck, and the inside of the legs. A common recessive variant is the white tiger, which may occur with the correct combination of parents; they are not albinos. Black or melanistic tigers have been reported, but no live specimen has ever been recorded. Also in existence are golden tabby tigers (also called "golden tigers" or "tabby tigers") which have a golden hue, much lighter than the colouration of normal tigers, and stripes that are brown. This variation in colour is very rare, and only a handful of golden tabby tigers exist, all in captivity.
The stripes of most tigers vary from brown/grey to pure black, although white tigers have far fewer apparent stripes. The form and density of stripes differs between subspecies, but most tigers have in excess of 100 stripes. The now extinct Javan Tiger may have had far more than this. The pattern of stripes is unique to each animal, and thus could potentially be used to identify individuals, much in the same way as fingerprints are used to identify people. This is not, however, a preferred method of identification, due to the difficulty of recording the stripe pattern of a wild tiger. It seems likely that the purpose of stripes is camouflage, serving to hide these animals from their prey (few large animals have colour vision as capable as that of humans, so the colour is not so great a problem as one might suppose).
Method of killing
Tigers ordinarily overpower their prey from any angle, usually from ambush, and bite the neck, ordinarily breaking the prey's spinal column or windpipe, or severing the jugular vein or carotid artery.
Powerful swimmers, tigers are known to kill prey while swimming. Some tigers have even ambushed boats for the fishermen on board or their catch of fish.
There are eight separate subspecies of tiger, three of which are extinct and one of which is almost certain to become so in the near future. Their historical range (severely diminished today) ran through Russia, Siberia, Iran, Afghanistan, India, China and southeast Asia, including the Indonesian islands. These are the surviving subspecies, in descending order of wild population:
- The Bengal Tiger (Panthera tigris tigris) is found through the forests and grasslands of Bangladesh, Bhutan, China, India and Nepal. It is the national animal of both Bangladesh and India. The estimated wild population of this subspecies is 3000 to 4600, most living in India and Bangladesh. These tigers are under severe pressure from both habitat reduction and from poaching; some recipes in Chinese medicine (in particular cures for impotence) require parts of tigers. Project Tiger, an Indian conservation project launched in 1972, has had limited success in protecting this subspecies.
- Indochinese Tiger (Panthera tigris corbetti), also called Corbetts tiger, is found in Cambodia, China, Laos, Malaysia, Myanmar, Thailand and Vietnam. Estimates of its population vary between 1200–1800, but it seems likely that it is in the lower part of this range. The largest current population is in Malaysia, where illegal poaching is strictly controlled, but all existing populations are at extreme risk from habitat fragmentation and inbreeding. In Vietnam, almost three-quarters of the tigers killed end up providing stock for Chinese pharmacies and the tiger is seen by poor native people as a resource through which they can ease poverty.
- The Sumatran Tiger (Panthera tigris sumatrae) is found only on the Indonesian island of Sumatra. The wild population is estimated at between 400 and 500 animals, occurring predominantly in the island’s five national parks. Recent genetic testing has revealed the presence of unique genetic markers, indicating that it may develop into a separate species, if it is not made extinct. This has led to suggestions that Sumatran Tigers should have greater priority for conservation than any other subspecies. Habitat destruction is the main threat to the existing tiger population (logging continues even in the supposedly protected national parks), but 66 tigers were recorded as being shot and killed between 1998 and 2000—nearly 20% of the total population.
- The Siberian Tiger (Panthera tigris altaica), also known as the Amur, Manchurian or North China tiger, is now confined almost totally to a very restricted part of eastern Russia where they are now protected. There are less than 400 of these tigers in the wild today, and many populations are likely to no longer be genetically viable, subject to potentially catastrophic inbreeding.
- The South China Tiger (Panthera tigris amoyensis), also known as the Amoy or Xiamen tiger, is the most critically endangered subspecies of tiger, and will almost certainly become extinct. It seems likely that the last known wild South Chinese tiger was shot and killed in 1994, and no live tigers have been seen in their natural habitat for the last 20 years. In 1959, Mao Zedong declared the tiger to be a pest, and numbers quickly fell from 4000 or so to approximately 200 in 1976. In 1977 the Chinese government reversed the law, and banned the killing of wild tigers, but this appears to have been too late to save the subspecies. There are currently 59 known captive Chinese tigers, all within China, but these are known to be descended from only 6 animals. Thus, the genetic diversity required to maintain the subspecies no longer exists, making its eventual extinction very likely.
- The Javan Tiger (Panthera tigris mondaica) was limited to the Indonesian island of Java. It now seems likely that this subspecies was made extinct in the 1980s, as a result of hunting and habitat destruction, but the extinction of this subspecies was extremely probable from the 1950s onwards (when it is thought that fewer than 25 tigers remained in the wild). The last specimen was sighted in 1979.
- The Caspian Tiger or Persian Tiger (Panthera tigris virgata) appears to have become extinct in the late 1960s, with the last reliable sighting in 1968. Historically it ranged through Afghanistan, Iran, Iraq, Pakistan, the former Soviet Union and Turkey.
- The Balinese Tiger (Panthera tigris balica) has always been limited to the island of Bali. These tigers were hunted to extinction—the last Balinese Tiger is thought to have been killed at Sumbar Kima, West Bali on 27 September, 1937; this was an adult female. No Balinese Tiger was ever held in captivity. The tiger still plays an important role in Balinese Hindu religion.
Tigers in literature and popular culture
The tiger has certainly managed to appeal to man's imagination. Both Rudyard Kipling in The Jungle Books and William Blake in his Songs of Experience depict him as a ferocious, fearful animal. In The Jungle Books, the tiger Shere Khan is the biggest and most dangerous enemy of Mowgli, the uncrowned king of the jungle. Even in the cutesy Bill Watterson comic strip, Calvin and Hobbes, Hobbes the tiger sometimes escapes his role of cuddly animal. At the other end of the scale there is Tigger, the tiger from A. A. Milne's Winnie the Pooh stories, who is always happy and never induces fear. In the award winning A Tiger for Malgudi, a Yogi befriends a tiger.
A stylized tiger was a mascot of the 1988 Olympic Games of Seoul. Tigers have been used in advertising such commodities as gasoline and breakfast cereal in long-standing advertising campaigns.
- Smilodon (popularly known as the Sabertooth tiger)
- Tiger Temple, a Buddhist temple in Thailand famous for its tame tigers
- Siegfried & Roy, two famous tamers of tigers
- Project Tiger
- Jim Corbett, Man-eaters of Kumaon, Oxford University Press, 1946
- Sierra Club (A Tiger Conservation project)
- Tiger Territory
- Enchanted Learning Software - All About Tigers
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