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The Cat Survival TrustThe TigerPanthera tigris Linnaeus
DescriptionOne of the most familiar of cats, the tiger is also one of the most endangered.The reddish-orange or ochre coat is marked with the famous dark vertical stripes. No two tigers have identical markings, one individual can be very asymmetrical. Stripes on the tail form rings, the underside is white or tinged with buff. The backs of the relatively small, rounded ears are black with white central spots. The hair on the back of the neck of some tigers may be almost mane-like. Physically, lions and tigers are almost equivalent. Their skulls are very similar, but in general the tiger’s is more massive and more arched. The tiger skull is therefore more superficially “catlike” because the facial part is shorter and more rounded. On average the nasal bones are longer and narrower in tigers. Zygomatic arches or cheek bones are extremely wide and thick in both species but more so in the tiger. The sagittal crest to which the neck muscles are attached, is higher and larger in lions. The bottom edge of the lower jawbone is convex in lions and more concave in tigers. Both species usually have the anterior upper premolar. As an inhabitant of open country, the lion has a more athletic posture than that of the forest-dwelling tiger. There is considerable variation within both species. Eight subspecies of tigers are described and generally accepted although some very recent work in molecular biology casts doubt on their validity (Cat News 26 p. 2):
Latitude and size seem to be correlated; tigers from the highest latitudes are larger and have more dense and longer coats. Corbett’s tiger is smaller than the Bengal tiger, darker in colour, and its stripes tend to break into spots. The black stripes of the Chinese tiger are broader and more widely spaced. Island forms of the tigers are, or were, smaller and darker than the “mainland” forms. The remaining skins of the Balinese tiger are the darkest of all. Although their coats are relatively short, Sumatran tigers have the largest facial ruffs. Siberian tigers are not, on average, much longer than Indian or Bengal tigers, but they are much heavier and more powerfully built. In particular, the muzzle is relatively broader and more massive than the other tigers. Siberian tigers are the largest cats in the world. Old males have characteristically huge heads and massive forequarters. They have a very full, and long winter coat making them appear to be extremely stocky, and they may put on a layer of fat more than 5 cm thick. The winter coat is rather pale and the stripes tend to be brown rather than black. Many felids express a relatively high degree of melanism i.e. dark or almost black pigmentation. There have been no verified specimens in which this has been manifest in tigers. In contrast white tigers have become world famous, especially those of Rewa in India. The local maharaja began breeding them in captivity in 1951. Some white tigers were pure albino, lacking pigmentation, but those of Rewa had ice-blue eyes and brown/black stripes on a white or cream background. This colour type is known as “chinchilla”. Yellow pigmentation is reduced to almost pure white, and black becomes sepia brown. This is a result of a mutation in one recessive gene; if the white tigers are mated with normal coloured tigers, the offspring are also normally marked. There has been a lot of dispute about the sizes of tigers, with “sportsmen” gaining kudos for the biggest “bag”. Confusion has arisen from the methods used, some hunters measuring the nose to tail lengths along the curves of the back and others a straight line between pegs. The former method was particularly open to abuse, or “inaccuracies”. Principal dimensions
Distribution and Habitats
Originally widespread, tigers were found in a very diverse variety of habitats: savannah, mangroves and temperate, coniferous and tropical rain forests. They require sufficient cover, year-round access to water, and a steady supply of suitable large prey.Their former distribution was from eastern Turkey and Transcaucasia through India and Indo-China to the Indonesian islands Java and Bali. There is no evidence to suggest that they inhabited the Tibetan plateau, but they do live in the foothills of the Himalayas, usually below 1,300 metres but occasionally higher and have killed domestic animals at 2,700 metres. One was seen at 3,960 metres. Amur or Siberian tigers live at 1,200 metres and descend in winter. Although the tiger was never found in central Siberia it was found regularly up to 50 degrees north latitude in the broad-leaved and mixed forests of the Far East. In 1905 a tiger was shot at 60 degrees 40 minutes north latitude. Tigers have also been seen on the island of Sakhalin when the Tartar Strait froze. Tigers have suffered extreme persecution and their distribution has been considerably restricted. Contemporary wild populations are now small and mostly relicts. The map shows most of the present distribution of tigers in grey; the Amur tiger occupies a small area, mainly in Russia, near the East coast just north of this map. The map is based on information in the Wild Cats Status Survey and Conservation Action Plan published by the IUCN/SSC Cat Speialist Group in 1996. See our Books page for more details. DietThe main prey animals of tigers in India are deer, buffalo, wild pigs, porcupines and langur monkeys. If they have the opportunity they will kill wolves, young rhinoceros, young elephant and even leopards. As a very large solitary carnivore, a tiger regards all animals it encounters as potential food.A tiger is able to kill a full grown adult bull gaur, and yet can be killed by a wild boar and wild dogs. The Siberian tigers seem to prefer to prey on Manchurian wapiti and wild pig, and have been known to take brown bears and lynx. Rotting flesh and birds are also eaten by tigers and occasionally they supplement their diets with fruit. Like domestic cats, tigers eat grass in order to improve their digestion. A female must kill approximately every eight days, and when lactating or producing milk, every five days or so. BehaviourThe social system of the tiger is fairly typical for a wild cat. They avoid one another but are very much aware of the presence of other tigers. The male maintains an exclusive home-range which encompasses two or more non-overlapping female ranges.Urine spraying is the most used form of territory delineation, visual clues such as tree scratching and defecation in ground scrapes are also used. Range size is influenced by prey type and availability. High quality habitats, with high prey densities are occupied by prime tigers of both sexes. Young males and older individuals are pushed out. In Siberia male home ranges are 800-1,000 km2, in Nepal 60-72 and in India 78. Female ranges in similar regions are respectively: 100-400; 16-20 and 65 km2. Corbett estimated a tigress to have a range covering 3,885 km2. Kaplanov studied Siberian tigers and identified a male who ranged over 3,200 km2 and a female who habitually hunted over 4,200 km2 (Guggisberg 1975). Males cannot afford to be very strictly territorial, their ranges are simply too big, so strangers are able to pass through. Territorial defence is passive but males do fight and kill one another in competition for space. Adult females are rather more stable in their ranges, and tend not to expand even when a next-door neighbour dies. Evidence shows that tigers often cover 20 to 50 km in one day. Individuals in search of a territory will roam very much more widely. Females who are not holding ranges do not or cannot breed. During the first month of birth the mother’s range will shrink to a quarter of her normal. As the cubs mature this will gradually expand. Tigers display a marked aversion to heat and will actively seek out shade. In hot weather tigers like to lie in water. They can easily swim 4 miles, and they are evidently at home in the marshy Sundarbans. Reports from 150 years ago state that tigers were often found during the day. Their camouflage is extremely effective even in broad daylight. The years of persecution have favoured those tigers which were secretive and preferred to move and live in cover, or learned to be so. Like lions, tigers will often roar after they have made a kill. Parihar in 1989 observed an injured tiger deliberately treating an open wound (Self-help Medical Treatment by a Tiger. Cat News, 13, 1990, p.2). The animal made a paste of clayey-loam soil with its saliva by chewing. Then the tiger spat it out, and applied it to the wound by rolling in the paste. Despite their asocial reputations, as many as six adult tigers have been observed to share a kill, feeding together (Thapar 1989). Siblings do occasionally stay together after leaving their mothers. There have even been reports of co-operative hunting between the mother and her cubs and between grown siblings. A mother, two male cubs, a three year-old male and an adult male have all been observed interacting, rubbing together and playing (A Glimpse of Tiger Family Life. Cat News 11, 1989, p.16). Depending on the available cover, prospective prey are stalked and rushed from 9 to 25 metres. Deer apparently seem to feel safe at a distance of 30 metres from a tiger, provided it is visible. (Thapar 1986). The tiger’s target is usually the neck, if hit with sufficient force the vertebrae will be dislocated, killing the prey instantly. If the victim struggles the bite will be transferred to the throat. Small or medium prey is despatched with a neck bite which aims to damage or sever the spinal cord. A suffocating throat bite which obstructs the larynx and carotid arteries is used for larger prey. Carcasses are usually dragged into cover. Tigers have been known to sleep on top of a dead animal on order to protect it from the depredations of vultures and crows. After the first period of eating a tiger will go to drink and lay up in the vicinity of the body. Schaller estimated that for every kill, a tiger may have to make as many as twenty attempts. Destruction of the tiger’s natural prey base has been significantly responsible for many of the instances of man-eating. Overhunting removes the animals upon which the tiger relies for food. This usually happens before their habitat is destroyed so although they have a home their food resource has been depleted. The tigers either face starvation or find alternative sources of food: livestock or people. Old, infirm or wounded tigers are usually the culprits, but not always; tigers in prime condition will prey on humans. Jim Corbett killed the notorious Champawat Tigress in 1907. She had a broken canine and was responsible for the deaths of 436 people. During the Second World War, tigers in Burma got an appetite for human flesh by feeding on the corpses left behind after fighting, or from dead prisoners of war. In the past 20 years, more than 800 people have been reported to have been killed by tigers in the Sundarbans mangrove on the borders of India and Bangladesh. Most of these deaths could have been avoided. In the Bangladesh Sundarbans more than 100 were killed from 1989 to 1991 (Heavy Death Toll to Tigers in Bangladesh. Cat News 16, 1992, p.6). Understandably these tragedies create serious problems for the conservation of these animals. About 8,000 people have permits to enter the Sundarbans Tiger Reserve to collect wood and honey and to go fishing. Sufficient prey seems to exist but tigers still prey on humans. They swim out to boats to seize fishermen. Electrified human dummies have been used with considerable success to discourage attacking tigers. The predators now associate what used to be food with a mild electric shock. Masks have also helped save lives. Tigers generally stalk and attack from behind. Human face masks worn on the back of the head confuse them. Several have been seen following people but not pressing an attack. In 1987 when the masks were introduced, 30 were killed, but no-one wearing a mask (Man-eaters and Masks. Cat News 11, 1989, p. 12). Since then it has become compulsory to wear a mask and only one has been attacked from the side. Man-eating has also been recorded from Sumatra, Malaysia and Indo-China. It appears to be uncommon in Manchuria and Siberia, there have been no recorded cases of unprovoked tigers attacking people, even where there have been relatively close contacts in the Primorjie region. Near Lazo in February 1976, a tiger killed and ate part of a tractor driver. Tigers generally try to avoid contact with people. ReproductionAlthough tigers mate at all times of the year, there are certain periods of noisy mating activity. In southern India this time is usually in April and May and to a lesser degree between October and November. In northern India, most activity is during November-February. In Malaysia and Indo-China mating occurs between November and March. Further north, in Manchuria and the Siberian Far East, tigers mate most frequently at the end of December and in January.A tigress may be pursued by several males who will fight to establish the victor. Copulation is extremely frequent, more than 50 times in one day, during which the male will grasp the scruff of his partner’s neck in his teeth. Gestation periods of the Siberian tiger on average 103 (93-112) days, appears to be longer than that of smaller Bengal tiger 95-109 days. Litters are usually of two or three cubs, but sometimes as many as six. Sumatran tiger cubs weigh about 750 grammes at birth, those of the Bengal 1,100-1,800 grammes and those of the Siberian 1,359 (785-1,760) grammes. Their eyes open after the first week, and the milk teeth erupt at the end of the second week. By 20 days the cubs can usually walk. Coat colour of the cubs tends to be rather light and it darkens to the adult shade in about three and a half to five and a half months. Lactation lasts for about five or six months and the young tigers begin to eat meat between six and eight weeks. At one year of age a tiger can fend for itself, but cubs tend to stay with their mothers for about two years. Siberian tigers develop more slowly and may not leave their mothers for four years. When the mother has a new litter the old one usually disperses. It is rare to see a female with two different litters at the same time. Young male tigers disperse much further than females who tend to settle near to their natal range. Siberian tigresses reach sexual maturity in 48 (37-60) months in the wild, younger in captivity. Males grow faster as cubs, usually mature later, in four or five years. Corbett gave evidence of a three year old male mating. Tigers are generally fully grown at five years old. A senile Siberian tiger once lived for 26 years in captivity. Conservation StatusRising human populations, extreme poverty and developmental activities are the root causes of most environmental problems. The tiger is also affected by cultural factors, many nations revere the tiger as a magnificent symbol, others regard it as a source of potent medicine.In the past 50 years three of the eight subspecies have become extinct. The early success of Project Tiger, set up in India in 1973, was hailed as a great conservation success story. It created worldwide complacency about the future of the tiger. This has proved to be unfounded. Urgent action to protect the remaining wild tigers is absolutely vital. Recent estimates put the numbers of wild tigers between 4,600 and 7,700 (P. Jackson: The Status of the Tiger in 1993 and threats to its future. Cat News, 19, 1993, p.5-11). About half of all the tigers are in India. But the Indian census methods are widely criticised as being overinflated. Some of the agencies responsible for the implementation of the tiger projects link tiger numbers to management performance. They wish to show that their tiger numbers are at least constant, or are increasing. Therefore there are more tigers on paper than there are in the wild. The problem is that many wildlife managers are untrained in wildlife biology (U. Karanth: Management Options for Wild Tigers. Cat News, 17, 1992, p. 4). It is estimated by the Cat Survival Trust that at the end of 1994 the real total of wild tigers was less than 4,200 and the total of all stud book tigers in captivity, less than 1,200! Basic tiger protection is inadequately funded and management is hampered by the lack of basic biological data on the populations. Poaching has markedly increased in recent years, there is strong evidence from India and Nepal. The value of tiger bones has increased dramatically, outstripping the value of skins. This is due to the ruthless Chinese demand for ingredients for traditional medicines. Tiger parts, bones in particular, are regarded as miracle cures. Estimates of tiger numbers remaining in China are less than 100. Half of those remaining are Siberian, the rest the wholly indigenous P. t. amoyensis. If this subspecies is not carefully protected and encouraged, the South Chinese tiger will become the fourth subspecies to become extinct in the wild this century. There are only a handful of scattered individuals lingering with scarcely the barest hope of recovery. Recently the Chinese Government declared that the Siberian tiger was increasing in China, they stated that there was now at least 100. A leading Russian tiger biologist, Dimitry Pikunov said that the Chinese scientists themselves stated that there were fewer than 20 (Xinhua Claims Siberian Tigers Increasing. Cat News 20, 1994, p.6-7). Eradicating the deeply held beliefs of the Chinese is vital to ensure the long-term survival of the tiger. Pressure for healing products is considerable. Although the State Council of China announced a ban on tiger bones in traditional medicine on 29th May 1993, the demand for them is not likely to disappear in the foreseeable future (China Bans Tiger Bone and Puts Tiger Farm in Limbo. Cat News, 19, 1993, p.3-4). Bones are very easily passed off as those of domestic animals which are legally traded. Only experts can identify them, unlike the characteristic skins. Poachers killed at least half of the famous tigers in India’s renowned Ranthambhore Tiger Reserve. Extensively studied and written about by Valmik Thapar, these tigers were familiar to millions of people. This loss was a key factor in alerting the world to the critical situation which now exists (Poaching for Bones Threatens World’s last Tigers. Cat News 17, 1992, p.2-3). Thapar set up the Ranthambhore Foundation, which aims to cater for the needs of the people who live around the reserve as well as the tigers. Conservation projects now have new priorities; to work together with the locals and to gain their essential support. Serious problems arise if this is not done. Heavy handed dealing with poachers in Nagarhole National Park in southern India caused a mob riot. Forest staff were driven out and vast areas of forest were burned. In Manas Tiger Reserve, again in India, a political struggle caused armed gangs to invade the reserve, they killed forest guards and let in poachers. Islands of protected tiger habitat exist, these areas are threatened. The tigers in them are often unable to migrate out so the populations become extremely inbred. Professor P. Leyhausen (What is a Viable Tiger Population? Cat News 4, 1986, p.3-4) recommends that 300 tigers is the absolute minimum necessary. This however is an unattainable ideal. Nowhere in India is there an area of suitable unbroken tiger habitat large enough to sustain a population of this size. Therefore there is little hope for a self-perpetuating population. The tiger is on Appendix I of the Convention on International Trade in Endangered Species, CITES. Only six of the 14 countries which have tigers are signatory to CITES. In those countries enforcement is seriously deficient. Most of the remaining reserves hold too few tigers to maintain viable populations. Captive populations have too little genetic diversity. The area of marsh and mangrove known as the Sundarbans supports the largest single population of tigers extant in the wild. Free ranging tiger populations are too small and fragmented to ensure their future survival except in the Sundarbans. However, the human pressures on the forests and reserves are increasing, this creates conflict of interests. Tiger ranges are constricted when the habitat available is reduced. This crowding leads to increased competition between neighbouring individual tigers. Tigers are killed, seriously injured or unable to reproduce as a consequence of these more frequent confrontations. The constraints on territory size for males is that they must encompass several females. Female tigers have to be able to utilise a range which can provide enough food to support lactation and to provide several den sites. If they cannot have sufficient space then they will not survive. We are left with the expectation that tigers will become extinct in the wild. The IUCN Red List has the Amur tiger (P. t. altaicaP. t. amoyensis) and Sumatran tiger (P. t. sumatrae) as Critically Endangered and all other surviving tigers as Endangered. (Cat News 23, 1995, p. 21) Latest NewsCaptive Breeding and Tigers in Captivity
This is achieved by the maintenance of a studbook which is used to select suitable breeding partners for captive animals. Such studbooks are maintained on a voluntary basis by dedicated individuals or teams at various zoos around the world. Zoos which have Tigers
Latest update: 3rd December, 1999 © September 1996 The Cat Survival Trust, The Centre, Codicote Road, Welwyn, AL6 9TU, England.
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