Tiger

Name and taxonomy

Carl Linnaeus named the tiger Felis tigris in 1758, when every cat sat in the genus Felis. Reginald Innes Pocock moved it into the genus Panthera in 1929. The English word came through Old French and Latin from the Greek tigris. An old story links the name to an Armenian or Persian word for an arrow, but scholars now doubt the connection. The other members of Panthera are the lion, the leopard, the jaguar and the snow leopard, the cats that can roar.

Naturalists proposed nine tiger subspecies over about two hundred years, from the 1800s onward. Most were told apart by fur length, colour and stripe pattern on museum skins, which is a weak basis. In 2017 the Cat Specialist Group accepted only two: P. t. tigris on the mainland and the smaller P. t. sondaica on the Sunda Islands. A 2018 genome study of six living populations found each one to be a separate branch. The IUCN still has the question under review.

Evolution and relatives

Genetic work makes the snow leopard the tiger's closest relative. The two lines split between 2.70 and 3.70 million years ago. The oldest remains of the modern species are pieces of jaw found in Lantian County, China, from the early Pleistocene. Later Pleistocene tigers turn up across China, Sumatra and Java, and fossils are known from Borneo and the Philippines. Supposed tiger bones from Japan belong to the cave lion.

Every living tiger descends from a single ancestor of 108,000 to 72,000 years ago. The population shrank around 115,000 years ago during a glacial period, then spread out again from a refuge in Indochina. In zoos, tigers have bred with lions. A liger, from a lion father and a tiger mother, grows far larger than either parent, while a tigon stays parent-sized. These hybrids often carry serious birth defects, so breeding them is widely seen as unethical.

Appearance

The tiger has the standard cat build: a muscular body, short strong legs, wide front paws and a large head. The head and body measure 1.4 to 2.8 metres, and the tail adds 0.6 to 1.1 metres. An adult stands 0.8 to 1.1 metres at the shoulder. Male Bengal tigers weigh 200 to 260 kilograms, and females 100 to 160 kg. Island tigers are much smaller: a female Sumatran tiger can weigh as little as 75 kg. The claws are curved and retractile and can reach 10 centimetres.

The coat is orange, from yellowish to reddish, with white on the belly, the inner legs and parts of the face. Black or dark brown stripes run mostly vertically down the body, and no two tigers share the same pattern. The pattern is in the skin as well as in the fur. Each ear carries a white spot on the back, ringed with black. The stripes break up the outline among trees, reeds and tall grass, and the orange probably reads as green to colour-blind deer.

No cat has longer canine teeth: they measure 6.4 to 7.6 centimetres. White tigers carry a recessive gene and have sepia stripes on a white ground. Only 0.001% of wild tigers carry the genes for it, and the many white tigers in captivity come from inbreeding. In Simlipal National Park in India, around 37% of tigers have thick merged stripes, a sign of genetic isolation.

Habitat and range

The tiger is a forest animal, but it is not fussy about the kind of forest. In the Russian Far East it lives among Korean pine and mixed broadleaf woods, in deep snow. On the Indian subcontinent it uses moist and dry tropical forest, floodplain grassland and the mangroves of the Sundarbans. In Sumatra it ranges from lowland peat swamp to rugged mountain forest. A tiger needs three things: cover, water and enough prey. In Bhutan it has been recorded at 4,200 metres.

The historic range ran from eastern Turkey and Iran through Central Asia and India to Siberia, Java and Bali. As of 2022 the tiger occupies less than 7% of that area. It survives in scattered blocks in India, Nepal, Bhutan, Bangladesh, Southeast Asia, Sumatra, northeast China and the Russian Far East. India holds the most tiger habitat, with 300,508 square kilometres, followed by Russia. GBIF holds records from 42 countries, but that figure includes zoos and is not the native range.

Density depends on prey. Jim Corbett National Park in northern India supports 12 to 17 tigers per 100 square kilometres. Logged forests in Myanmar, Thailand and Malaysia hold under one tiger per 100 square kilometres.

Diet and hunting

The tiger is an apex predator that feeds mainly on large and medium hooved mammals. Sambar, chital, wapiti, barasingha, gaur, water buffalo and wild boar make up most kills. In the Russian Far East, red deer and wild boar together made up 84% of recorded kills. It also takes monkeys, peafowl, porcupines, fish and even bears when the chance comes. Near villages it kills livestock and dogs.

A tiger hunts by ambush, mostly at night. It finds prey by sight and hearing, creeps close with its head low, and freezes between moves. The rush starts from about 30 metres, and if the prey sees it first, the tiger gives up. It can sprint at 56 kilometres per hour and leap 10 metres, but it cannot keep a chase going. Only about one attack in 10 to 20 ends in a kill.

The tiger attacks from behind or from the side and tries to pull the animal over. Large prey dies from a bite that holds the throat until it stops breathing. Small prey dies from a neck bite that breaks the spinal cord. It drags the carcass into cover, rests, then eats up to 50 kilograms in one session. One tiger moved a dead gaur bull of 700 kg on its own. It feeds on a large kill for several days and leaves little for scavengers.

Behaviour and social life

Adult tigers live alone. The only lasting bond is between a mother and her cubs. Each adult defends a home range against others of the same sex, and a male's range covers several female ranges. Two females in the Sundarbans held ranges of only 10.6 and 14.1 square kilometres. In the Sikhote-Alin reserve in Russia, females used 248 to 520 square kilometres and males 847 to 1,923.

Tigers mark their ranges with sprayed urine, claw marks on trees, scrapes on the ground and droppings on trails. A range left empty by a death can be claimed within days. Most disputes end with threats rather than a fight. The worst fights happen between two males over a female in heat. A male will sometimes share a kill with the females and cubs in his range, and let them eat first.

Young tigers disperse up to 650 kilometres to reach other populations. Daughters settle near their mother, while sons travel further. A tiger swims well and crosses rivers up to 8 kilometres wide, and it lies in water on hot days. Its size makes it a poor climber compared with smaller cats, though cubs climb often. Tigers may cover 16 to 32 kilometres in a single night.

Communication and senses

A tiger is usually silent, but it has a wide range of calls. The roar tells other tigers where it is and carries about 3 kilometres. A softer moan, made with the mouth partly closed, carries 400 metres and signals tension or submission. Friendly tigers make a low snort called a prusten, the big-cat version of a purr. Mothers grunt to their cubs, cubs miaow back, and a startled tiger gives a short woof.

Scent does most of the long-term work. Both sexes pull the flehmen grimace, with curled lip and bared teeth, when they smell a urine mark. A male uses it to tell when a female is ready to mate. The white ear spots are flashed during aggressive meetings and between mother and cubs. The tail signals mood too: raised and swaying for a friendly approach, low and still when calm. Like other cats, the tiger sees well in low light, which suits its night hunting.

Reproduction and life cycle

Tigers breed in any month, with a peak between November and April. A female is in heat for three to six days, and the cycle returns every three to nine weeks. She calls the resident male by roaring and scent marking. A pair can remain together for as long as four days and mate many times, each mating lasting under 20 seconds. Gestation lasts about 105 days.

The mother gives birth in thick vegetation, a cave or under a rock. A litter holds two to four cubs as a rule, though up to seven have been recorded. A newborn weighs 785 to 1,610 grams and is blind. The eyes open between 3 and 14 days after birth. If the den seems unsafe, she moves the cubs one by one, carried by the scruff of the neck. At about two months the cubs leave the den, start on meat and follow their mother.

Weaning ends at about six months, and cubs join hunts at eight to ten months. A cub can make its first kill at 11 months and leaves its mother at 18 to 24 months. Females mature at three to four years and males at four to five. A new male that takes over a range may kill the cubs of the old one. In Chitwan National Park, 12 of 56 cubs and juveniles died that way over seven years. Wild tigers usually live 8 to 10 years, and captive tigers 16 to 18, with a record of 26.

Predators and threats

An adult tiger has no natural predator apart from people. Cubs die from other predators, floods, fires, injuries and the loss of the mother. Adult males kill cubs they did not father, and they sometimes kill young tigers that wander into their range. Large prey such as gaur, buffalo and boar can wound or kill a tiger. A big pack of dholes can kill a tiger too. Tigers carry tapeworms and nematodes, and canine distemper has killed Siberian tigers.

The real threats are people. Forest is cleared for plantations, roads, railways and mines, which cuts the range into small isolated blocks. In Peninsular Malaysia alone, 8,315.7 square kilometres of tiger habitat went between 1988 and 2012. Poachers set snares for skins, bones, teeth and claws, and the parts go into traditional medicine. Between 2000 and 2022 at least 3,377 tigers were seized in 2,205 raids across 28 countries. Villagers also kill tigers in revenge for lost cattle.

Population and conservation

The IUCN Red List has rated the tiger Endangered since 1986. The world population fell from an estimated 5,000 to 8,262 in the late 1990s to 3,726 to 5,578 in 2022. The occupied range shrank by 53% to 68% over the same period. The Siberian, South China and Sumatran tigers are each rated Critically Endangered on their own. South Korea lists the tiger as Regionally Extinct, and the Bali, Javan and Caspian tigers are gone.

Every range country protects the tiger by law, and CITES Appendix I bans trade in live tigers and their parts. India founded Project Tiger in 1973 and by 2022 had 53 tiger reserves covering 75,796 square kilometres. Nepal reached years of zero poaching after 2010, and its tiger numbers doubled in a decade. Russia has banned tiger hunting since 1952 and treats poaching as a serious crime.

Wildlife corridors now link reserves in the Terai Arc of Nepal and India, and tigers use at least nine of them. China and Russia agreed in 2019 to manage two border parks together. Kazakhstan is restoring habitat and prey to bring tigers back to the Ile-Balkash reserve. Zoos keep a coordinated breeding stock as insurance against extinction in the wild.

Relationship with humans

People have hunted tigers for thousands of years, and a rock painting at Bhimbetka in India shows it. Mughal emperors and European colonists hunted from horses and elephants, and an estimated 80,000 tigers died between 1875 and 1925. In most places tigers avoid people. Most attacks are defensive, but some tigers, often old or injured ones, do hunt people. The Champawat tiger killed over 430 people in Nepal and India before Jim Corbett shot her. In the Sundarbans, official records list 1,396 deaths between 1935 and 2006, mostly fishermen and honey collectors.

Tigers have been kept since Roman times, when they were killed in amphitheatres. A 2020 count found more than 8,000 tigers in captivity in Asia, over 5,000 in the United States and at least 850 in Europe. That is more tigers than live in the wild. Only 6% of the American captive tigers were in accredited zoos, and the United States banned private big cats in 2022. Circus acts with tigers peaked in the 20th century and have since declined.

Chinese traditional medicine has used tiger bone for over 3000 years, though no evidence shows it works. Tiger farms in China and in Southeast Asia raise the animals for their parts, which seems to increase demand rather than lower it. On the positive side, tigers draw tourists to Indian reserves and give local people a reason to protect forest.

In culture and myth

Where the lion stands for royalty in the West, the tiger plays that role across Asia. In ancient China the tiger was the king of the forest and a symbol of the emperor's power. It is the third of the 12 signs of the Chinese zodiac. Chinese astronomy has a White Tiger among its Four Symbols, standing for the west and autumn, opposite the Azure Dragon. A tiger appears on the Indus Valley Pashupati seal and on the coins of the Chola dynasty in southern India.

In Hindu tradition the tiger carries the goddess Durga into battle, and the tiger is India's national animal. Buddhist teaching groups the tiger with the monkey and the deer as the Three Senseless Creatures, and the tiger stands for anger. Korean myth makes tigers messengers of the Mountain Gods, and Korean and Chinese homes used tiger images to keep off evil spirits. In Malaysia and Indonesia, tiger shamans call on the animal to heal the sick. Weretiger stories occur across the range, and the Mnong of Indochina believed tigers could become human.

William Blake's poem The Tyger, from 1794, asks how the same maker could create the tiger and the lamb. In the Chinese novel Water Margin the bandit Wu Song kills a tiger with his bare hands. Shere Khan in Kipling's The Jungle Book is the enemy of Mowgli. Friendlier tigers include Tigger from Winnie-the-Pooh and Tony the Tiger on cereal boxes. A 2004 online poll across 73 countries put the tiger first among favourite animals, on 21% of the vote.