2007 Schools Wikipedia Selection. Related subjects: Mammals
Bengal Tiger (P. tigris tigris)
Historical distribution of tigers (pale yellow) and 2006 (green).
Tigris striatus Severtzov, 1858
Tigers (Panthera tigris) are mammals of the Felidae family and one of four " big cats" in the Panthera genus. They are apex predators and the largest feline species in the world, comparable in size to the biggest fossil felids. The Bengal Tiger is the most common subspecies of tiger, constituting approximately 80% of the entire tiger population, and is found in Bangladesh, Bhutan, Myanmar, Nepal, and India. An endangered species, the majority of the world's tigers now live in captivity.
Tigers are the heaviest cats found in the wild. Although different subspecies of tiger have different characteristics, in general male tigers weigh between 200 and 320 kilograms (440 and 700 lb) and females between 120 and 181 kg (265 and 400 lb). On average, males are between 2.6 and 3.3 metres (8 ft 6 in to 10 ft 8 in) in length, and females are between 2.3 and 2.75 metres (7 ft 6 in and 9 ft) in length. Of the living subspecies, Sumatran tigers are the smallest, and Amur (or Siberian) tigers are the largest.
Most tigers have orange coats, a fair (whitish) medial and ventral area and stripes that vary from brown or hay to pure black. 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 function of stripes is camouflage, serving to hide these animals from their prey. The stripe pattern is found on a tiger's skin and if shaved, its distinctive camouflage pattern would be preserved.
Like most cats, tigers are believed to have some degree of colour vision.
There is a well-known mutation that produces the white tiger, an animal which is rare in the wild, but widely bred in zoos due to its popularity. The white tiger is not a separate sub-species, but only a colour variation. There are also unconfirmed reports of a "blue" or slate-coloured tiger, and largely or totally black tigers, and these are assumed, if real, to be intermittent mutations rather than distinct species. Similar to the lion, the tiger has the ability to roar.
Most tigers live in forests or grasslands, for which their camouflage is ideally suited, and where it is easy to hunt prey that are faster or more agile. Among the big cats, only the tiger and jaguar are strong swimmers; tigers are often found bathing in ponds, lakes, and rivers and are known to kill while swimming. Tigers hunt alone and eat primarily medium to large sized herbivores such as sambar deer, but they also have the capability to eat much smaller prey such as birds, and other such things, wild pigs, young gaur, water buffalo and domestic cattle. They also kill such formidable predators as sloth bear, dogs, leopards, crocodiles and pythons as prey, and occasionally prey on creatures as small as langurs, peacocks and hares. Old and injured tigers have been known to attack humans or domestic cattle and are then termed as man-eaters or cattle-lifters which often leads to them being captured, shot or poisoned.
Adult elephants are too dangerous to tigers to serve as common prey, but conflicts between elephants and tigers do sometimes take place.
Tigers often ambush their prey as other cats do, overpowering their prey from any angle, using their body size and strength to knock prey off balance. Even with great masses, Tigers can reach speeds of about 60 km/h (37 mph). Once prone, the tiger bites the back of the neck, often breaking the prey's spinal cord, piercing the windpipe, or severing the jugular vein or carotid artery. Tigers prefer to bite the throats of large prey. After biting, the tiger then uses its muscled forelimbs to hold onto the prey, bringing it to the ground. The tiger remains latched onto the neck until its prey dies.
The Sundarbans mangrove swamps of Bengal have had a higher incidence of man-eaters, where some healthy tigers have been known to hunt humans as prey.
In the wild, tigers can leap as high as 5 m (16 ft) and as far as 9-10 m (30-33 ft), making them one of the highest-jumping mammals (just slightly behind cougars in jumping ability).
They have been reported to carry domestic livestock weighing 50 kg (110 lb) while easily jumping over fences 2 m (6 ft 6 in) high. Their heavily muscled forelimbs are used to hold tightly onto the prey and to avoid being dislodged, especially by large prey such as gaurs. Gaurs and water buffalo weighing over a ton have been killed by tigers weighing about a sixth as much. A single blow from a tiger's paw can kill a full-grown wolf or human, or can heavily injure a 150 kg (330 lb) Sambar deer.
Biology and ecology
Adult tigers are territorial and fiercely defensive. A tigress may have a territory of 20 km² while the territories of males are much larger, covering 60-100 km². Male territories may overlap those of many females, but males are intolerant of other males within their territory. Because of their aggressive nature, territorial disputes are violent and often end in the death of one of the males. Males will fight other males for territory. To identify his territory the male marks trees by spraying urine and anal gland secretions on trees as well as by marking trails with scat. Males show a behaviour called flehmen, a grimacing face, when identifying a female's reproductive condition by sniffing their urine markings.
A female is only receptive for a few days and mating is frequent during that time period. A pair will copulate frequently and noisily, like other cats. The gestation period is 103 days and 3–4 cubs of about 1 kg (2 lb) each are born. The females rear them alone. Wandering male tigers may kill cubs to make the female receptive. At 8 weeks, the cubs are ready to follow their mother out of the den. The cubs become independent around 18 months of age, but it is not until they are around 2–2½ years old that they leave their mother. The cubs reach sexual maturity by 3–4 years of age. The female tigers generally own territory near their mother, while males tend to wander in search of territory, which they acquire by fighting and eliminating a territorial male. Over the course of her life, a female tiger will give birth to an approximately equal number of male and female cubs. Tigers breed well in captivity, and the captive population in the United States may rival the wild population of the world.
In the wild, tigers mostly feed on deer, wild boar, and wild cattle, including gaur and water buffaloes, young rhinos and young elephants, and sometimes, even leopards and bears. Tigers have been known to kill crocodiles on occasion, although predation is rare and the predators typically avoid one another. Siberian tigers and brown bears are a serious threat to each other and both tend to avoid each other. Statistically though, the Siberian tiger has been the more successful in battles between the two animals because bears taken by tigers are often smaller sized bears, however tigers can and do kill larger brown bears. Even female tigers, which are considerably smaller than male tigers, are capable of taking down and killing adult gaurs by themselves. Sambar, wild boar and gaur are the tiger's favoured prey in India. Young elephant and rhino calves are occasionally taken when they are left unprotected by their herds. A case where a tiger killed an adult female Indian rhino has been observed.
Tigers prefer large prey such as sambar, gaur and wild water buffalo because they provide more meat and last for many days, avoiding the need for another hunt. In all of their range, tigers are the top predators and do not compete with other carnivores other than the dhole or Indian wild dog, which makes up for its relative lack of strength by numbers. They do not prey on large animals such as adult elephants and rhinos, although they will prey on their young whenever they have an opportunity. However, a desperate tiger will attack anything it regards as potential food, including humans.
Tigers have been studied in the wild using a variety of techniques. The populations of tigers were estimated in the past using plaster casts of their pugmarks. In recent times, camera trapping has been used instead. Newer techniques based on DNA from their scat are also being evaluated. Radio collaring has also been a popular approach to tracking them for study in the wild.
Humans are the tiger's most significant predator, as tigers are often poached illegally for their fur. Also, their bones and nearly all body parts are used in traditional Chinese medicine for a range of purported uses including pain killers and aphrodisiacs. Poaching for fur and destruction of habitat have greatly reduced tiger populations in the wild. A century ago, it is estimated there were over 100,000 tigers in the world; now numbers are down to below 2,500 mature breeding individuals, with no subpopulation containing more than 250 mature breeding individuals.
At the Kalachakra Tibetan Buddhist festival in south India in January 2006 the Dalai Lama preached a ruling against using, selling, or buying wild animals, their products, or derivatives. The result when Tibetan pilgrims returned to Tibet afterwards was much destruction by Tibetans of their wild animal skins including tiger and leopard skins used as ornamental garments. Time will show whether this causes a thankfully needed long-term slump in the demand for poached tiger and leopard skins.
There are nine subspecies of tiger, three of which are extinct and one of which is almost certain to become extinct in the near future. Their historical range (severely diminished today) ran through Russia, Siberia, Iran, Afghanistan, India, China and south-east Asia, including the Indonesian islands. The South China Tiger is believed to be the first tiger. These are the surviving subspecies, in descending order of wild population:
- The Bengal tiger or the Royal Bengal tiger (Panthera tigris tigris) is found in parts of India, Bangladesh, Nepal, Bhutan, and Burma. It lives in varied habitats - grasslands, subtropical and tropical rainforests, scrub forests, wet and dry deciduous forests and mangroves. The Indian government's estimated population figure for these tigers is between 3,100 and 4,500, some 3,000 of which are found in India alone. However, many Indian tiger conservationists doubt this number, seeing it as overly optimistic. The number of Bengal tigers in India may be fewer than 2,000, as most of the collected statistics are based on pugmark identification, which often gives a biased result. Even though this is the most 'common' tiger, these tigers are under severe pressure from both habitat destruction and poaching. In 1972, India launched a massive wildlife conservation project, known as Project Tiger, to protect the depleting numbers of tigers in India. The project helped increase the population of these tigers from 1,200 in the 1970s to 3,000 in the 1990s and is considered as one of the most successful wildlife conservation programs. At least one Tiger Reserve ( Sariska) has lost its entire tiger population to poaching. Male Bengal tigers range anywhere from 200 to 295 kg (440-650 lb) and females range between 120-180 kg (264-400 lb). Males in the wild usually weigh 205 to 227 kg (450-500 lb), while the average female will weigh about 140 kg (310 lb). However, the northern Indian and the Nepalese Bengal tigers are considerably bulkier than those found in other places, with recorded instances of shot males that weighed more than 300 kg (660 lb). One large male killed in Nepal in 1942 weighed 320 kg (706 lb), while another, killed in 1910 in India, weighed 317 kg (700 lb). The largest Bengal tiger ever shot was a male 3.3 m (11 ft) in total length and weighed close to 390 kg (857 lb); this giant was killed in 1967.
- The Indochinese tiger (Panthera tigris corbetti), also called Corbett's tiger, is found in Cambodia, China, Laos, Burma, Thailand, and Vietnam. Estimates of its population vary between 1,200 to 1,800, but it seems likely that the number is in the lower part of the 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 provide stock for Chinese pharmacies. Also, the tigers are seen by poor natives as a resource through which they can ease poverty. Indochinese tigers are smaller and darker than Bengal tigers. Males weigh from 150-190 kg (330-420 lb) on average while females are smaller at 110-140 kg (242-308 lb).
- The Malayan tiger (Panthera tigris jacksoni), exclusively found in the southern (Malaysian) part of the Malay Peninsula, was not considered a subspecies in its own right until 2004. The new classification came about after a study by Luo et al. from the Laboratory of Genomic Diversity Study, part of the National Cancer Institute of the United States. Recent counts showed there are 600-800 tigers in the wild, making it the third largest tiger population behind the Bengal tiger and the Indochinese tiger. The Malayan tiger is a national icon in Malaysia, appearing on its coat of arms and in logos of Malaysian institutions, such as Maybank.
- 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, seen chiefly in the island's 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, or nearly 20% of the total population. The Sumatran tiger is the smallest of all living tiger subspecies. Adult males weigh between 100-130 kg (220-286 lb), females 70-90 kg (154-198 lb). Their small size is an adaptation to the thick, dense forests of the Sumatra island where they reside, as well as the smaller-sized prey. On February 3, 2007 a pregnant Sumatran Tiger was caught by people from Rokan Hilir village at Riau province. Indonesian fauna conservation officials are planning to transfer her to the Bogor Safari Park in Java.
- The Amur tiger (Panthera tigris altaica), also known as the Siberian, Manchurian or North China tiger, is confined completely to the Amur region in far eastern Siberia, where it is now protected. The last two censuses (1996 and 2005) found 450-500 Amur tigers within their single and more or less continuous range making it one of the largest undivided tiger populations in the world. Considered the largest subspecies, with the exception of the northern Indian and the Nepalese Bengal tigers, the largest wild Amur tiger on record weighed 384 kg (845 lb), while two captive ones weighed 465 kg (1025 lb) and 423 kg (932 lb). Some Bengal tigers can grow to the same length as Amur tigers. Weights can vary substantially depending on whether the tiger has been fully fed or has an empty belly. The average weight of a male Amur tiger is around 227 kg (500 lb), but they can be anywhere from 205 to 364 kg (450-800 lb). The Amur tiger is also noted for its thick coat, distinguished by a paler golden hue and a smaller number of stripes. The Amur tiger is the largest and heaviest of all living felines. A six-month old Amur tiger can be as big as a fully grown leopard.
- 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 is also considered to be the first of all tiger subspecies. This subspecies is one of the smallest tiger species. The length of the South China tiger ranges from 2.2-2.6 m (87-104 in) for both males and females. Males weigh between 127 and 177 kg (280-390 lb) while females weigh between 100 and 118 kg (220-260 lb). It seems likely that the last known wild South China tiger was shot and killed in 1994, and no live tigers have been seen in their natural habitat for the last 20 years. In 1977, the Chinese government passed a law banning the killing of wild tigers, but this appears to have been too late to save the subspecies. There are currently 59 known captive South China tigers, all within China, but these are known to be descended from only six animals. Thus, the genetic diversity required to maintain the subspecies no longer exists, making its eventual extinction very likely. Currently, there are breeding efforts to reintroduce these tigers to the wild by 2008.
Extinct tiger subspecies
Tigers are uncommon in the fossil record. The distinct fossils of tigers were discovered in Pleistocene deposits – mostly in Asia. Nevertheless, tiger fossils 100,000 years old have been found in Alaska. Possibly because of a land bridge between Siberia and Alaska during the ice ages, this Alaskan tiger might have been a North American population of Siberian tiger. In addition, some scientists have discovered similarities between tiger bones and those of the American lion, an extinct big cat that dominated much of North America as recently as 10,000 years ago. Some have used these observations to conclude that the American lion was a New World tiger species.
Tiger fossils have also turned up in Japan. These fossils indicate that the Japanese tiger was no bigger than the island subspecies of tigers of recent ages. This may be due to the phenomenon in which body size is related to environmental space (see island dwarfism), or in the case of a large predator like a tiger, availability of prey.
- 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.
- The Javan tiger (Panthera tigris sondaica) 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, though it is thought that such a tiger was last shot dead in the south-eastern-most part of Turkey in 1970. Historically it ranged through Afghanistan, Iran, Iraq, Pakistan, the former Soviet Union and Turkey. This tiger was said to be yellow with black stripes. The Caspian tiger was one of two subspecies of tiger (along with the Bengal) that was used by the Romans to battle Roman Gladiators and other animals, including the Barbary Lion.
- The Trinil tiger (Panthera tigris trinilensis) is the oldest tiger fossil dating from about 1.2 million years ago. This tiger was found at the locality of Trinil, Java, Indonesia.
Tigers in literature and popular culture
The word "tiger" is borrowed from the Greek word "tigris", which itself is derived "possibly from an Iranian source." In American English, "Tigress" was first recorded in 1611. " Tiger's-eye" is a name for a golden-brown striped, chatoyant, fibrous variety of quartz used as a semi-precious gemstone.
The tiger has long been a subject of imaginative literature. Both Rudyard Kipling in The Jungle Book and William Blake in Songs of Experience depict the tiger as a menacing and fearful animal. In The Jungle Book, the tiger, Shere Khan, is the wicked mortal enemy of the protagonist, Mowgli. However, other depictions are more benign: Tigger, the tiger from A. A. Milne's Winnie the Pooh stories, is cuddly and likable. The famous comic strip Calvin and Hobbes features Calvin and his stuffed tiger, Hobbes.
The tiger is one of the most popular sport teams mascots. Some examples the American Major League Baseball team Detroit Tigers and the English rugby union club Leicester Tigers and the NCAA Division I sports teams, LSU Tigers, Auburn Tigers, and Clemson Tigers.
During Bleeding Kansas in 1850s, pro-slavery militiamen operating out of Missouri who raided anti-slavery settlements in Kansas styled themselves the "Tigers." This tradition survives in University of Missouri mascot "Tigers."
Humble Oil, a division of Standard Oil Company of New Jersey, USA, (Jersey Standard), used a caricatured tiger and the slogan "Put a Tiger in your Tank" to promote their gasoline/petrol products. Jersey Standard used a real tiger in its advertising when it took the Exxon name company-wide in 1972 and when advertising abroad as Esso. The brand kept the tiger mascot as a part of ExxonMobil when they merged in 1999.
The tiger is one of the 12 Chinese zodiac animals. Also in various Chinese art and martial art, the tiger is depicted as an equal rival towards the Chinese dragon. In Imperial China, a tiger often represented the highest army general (or present day defence secretary), while the emperor and empress were represented by a dragon and phoenix, respectively.
The tiger is regarded as the king of the jungle in most parts of Asia, because its forehead has a marking which resembles the Chinese character 王, which means "king". Consequently, many cartoon depictions of tigers in China are drawn with 王 on their forehead.
A stylized tiger cub, " Hodori", was a mascot of the 1988 Summer Olympic Games of Seoul.
The tiger as a national animal
The Tiger is the national animal of:
- Bangladesh (Royal Bengal Tiger)
- China, along with Dragon and Panda; the Tiger is the unofficial symbol
- India (Royal Bengal Tiger)
- Nepal (Royal Bengal Tiger)
- North Korea (Siberian Tiger)
- South Korea (Siberian Tiger)
- Former Nazi Germany along with the black eagle (currently it is the black eagle ( Bundesadler) (official) and leopard (unofficial)
- Former USSR (Siberian Tiger) (currently it is the Bear and golden bicephalic eagle)