TIGERS

The Largest Living Cat Species

The tiger (Panthera tigris) is the largest living cat species and a member of the genus Panthera. It is most recognisable for its dark vertical stripes on orange fur with a white underside. An apex predator, it primarily preys on ungulates, such as deer and wild boar. It is territorial and generally a solitary but social predator, requiring large contiguous areas of habitat to support its requirements for prey and rearing of its offspring. Tiger cubs stay with their mother for about two years and then become independent, leaving their mother’s home range to establish their own.

The tiger was first scientifically described in 1758. It once ranged widely from the Eastern Anatolia Region in the west to the Amur River basin in the east, and in the south from the foothills of the Himalayas to Bali in the Sunda Islands. Since the early 20th century, tiger populations have lost at least 93% of their historic range and have been extirpated from Western and Central Asia, the islands of Java and Bali, and in large areas of Southeast and South Asia and China. What remains of the range where tigers still roam free is fragmented, stretching in spots from Siberian temperate forests to subtropical and tropical forests on the Indian subcontinent, Indochina and a single Indonesian island, Sumatra.

The tiger is listed as Endangered on the IUCN Red List. As of 2015, the global wild tiger population was estimated to number between 3,062 and 3,948 mature individuals, with most populations living in small isolated pockets. India currently hosts the largest tiger population. Major reasons for population decline are habitat destruction, habitat fragmentation and poaching. Tigers are also victims of human–wildlife conflict, due to encroachment in countries with a high human population density.

The tiger is among the most recognisable and popular of the world’s charismatic megafauna. It featured prominently in the ancient mythology and folklore of cultures throughout its historic range and continues to be depicted in modern films and literature, appearing on many flags, coats of arms and as mascots for sporting teams. The tiger is the national animal of India, Bangladesh, Malaysia and South Korea.

For many years, scientists separated tigers into nine subspecies, including six living subspecies and three extinct subspecies. The living subspecies were Bengal tigers (Panthera tigris tigris), Amur tigers (P.t. altaica), South China tigers (P.t. amoyensis), Sumatran tigers (P.t. sumatrae), Indochinese tigers (P.t. corbetti) and Malayan tigers (P.t. jacksoni).

Humans wiped out the extinct tiger subspecies by hunting them and destroying their habitats. Bali tigers (P. t. balica) were last documented in the late 1930s, Caspian tigers (P.t. virgata) went extinct in the early 1970s and Javan tigers (P.t. sondaica) disappeared by the early 1980s, according to the IUCN Cat Specialist Group(opens in new tab).

In recent years, some researchers have challenged the traditional tiger classification. A 2015 study published in the journal Science Advances(opens in new tab) argued that there are only two subspecies of tigers: Sunda tigers, which combined Sumatran tigers and extinct Bali tigers and Javan tigers into one subspecies under the name P.t. sondaica, and continental tigers, a subspecies that contains all other tigers under the Bengal tiger name P.t. altaica. However, a study published in the journal Current Biology(opens in new tab) in 2018 presented genomic evidence supporting the traditional classification of six genetically distinct subspecies of tigers

The white tigers seen in some zoos are not a separate species or subspecies from orange tigers; rather, they are the result of a mutation in a single gene. A 2013 study published in the journal Current Biology(opens in new tab) found that a mutation in a pigment gene called SLC45A2 is responsible for stopping the production of red and yellow pigments that give normal tigers their color, resulting in tigers that are white with black stripes.

White tiger gene variations originate from the Bengal tiger population. However, the mutation is extremely rare in the wild, and the last known wild white tiger was hunted and killed in 1958. A white tiger that was captured in central India in 1951 and named Mohan is the ancestor of almost all white tigers in captivity today. Mohan’s descendants were deliberately inbred by humans to increase the chances of passing on his mutation. This inbreeding led to a range of health problems in the white tiger population, including premature deaths, deformities and stillbirths, according to the 2013 study.

Humans can also selectively breed tigers in captivity to change the color of their stripes to make them lighter and more golden. A rare genetic variation can even cause tiger stripes to broaden and fuse together so that the tiger appears blacker than usual. This “black tiger” coat is also seen in one population of wild tigers in Similipal Tiger Reserve in eastern India, likely because the population is small and isolated, with limited genetic diversity, according to a 2021 study published in the journal Proceedings of the National Academy of Sciences. (opens in new tab)

The IUCN categorizes tigers as endangered and lists illegal poaching as the main threat to the species. Tigers are poached so their body parts and fur can be sold as part of the illegal wildlife trade. Tiger bones are used in traditional Asian medicines, and similar markets seek tigers’ skin, teeth and other parts.

In addition to the threat of poaching, tiger habitat is being converted into agriculture or human settlements and commercially logged. Tiger attacks on humans and livestock also bring the big cats into conflict with people, who kill them in retaliation.

A 2013 study published in the journal Wildlife Biology in Practice(opens in new tab) found that tigers in the Sundarbans Reserved Forest region of Bangladesh killed an average of 22 people per year over a 63-year period. While the relative risk of a human being killed by a tiger in its range is low, such killings have a big impact on the families of the people who are killed and give tigers a bad reputation.