The tiger is at risk because of conflicts over values. When is a tiger worth more alive than dead? How do you make the habitat needed to sustain a tiger population worth more with tigers in it than without the tigers? Habitat alteration and human activities are largely responsible for the tiger population decline. It is highly dependent on cover, and cannot survive in cleared areas. Many of its former forest and grassland homes have been converted to agricultural land. A stressed ecosystem exacerbates the paucity and scarcity of food over long stretches especially along corridors connecting habitats, causing tigers to walk longer beats increasing the possibility that they could attack domestic cattle. Despite legal protection in almost all of its range, poaching is a problem, since in many areas the tiger is still regarded as a pest.
The illegal trade in tiger body parts is also a severe threat. Tiger bone sells for up to US $500 per gram; tiger penis for US $1700 per gram; and tiger skins sold in the Middle East fetch up to US $15,000 each.
Inadequate enforcement of national and international laws allows poaching and trade in tiger parts to continue in many countries, even in so called "protected areas".
Partial to untouched nature, tigers probably require over 10 km2 of individual habitat which exacerbates the problem of maintaining large predator populations in densely populated areas.
Fossils indicate that the tiger evolved in eastern Asia and could once be found from eastern Turkey to the Sea of Okhotsk, India, continental Southeast Asia, and the islands of Sumatra, Java and Bali. Today, tigers live no further west than India, and have vanished completely from Bali and Java. The eight subspecies of tiger are each adapted to a different habitat and climatic zone. Three of which are now believed extinct, the Javan tiger P. t. sondaica, Caspian tiger P. t. virgata and Bali tiger P. t. balica.
The main reason for the death of the last of the tigers in Kazakhstan was the extensive burning of reeds in the lower reaches of rivers during April and May every year, which destroyed all vegetation there in the 1930's through the 1940's. Tigers disappeared from the lower reaches of the Amu-Darya mainly because of fires, no more than a dozen existed in 1942, and by 1950 tigers were extirpated from the Amu Darya delta.
In Tajikistan their population decreased as a result of rapid cultivation of river floodplains. Finaly dislocated from their small range in Tajikistan in 1950 due to a riparian forest fire. Local hunters killed four in a three month period, in all likelihood ending the tiger's chances for reproduction. The last sighting of tiger tracks in Tajikistan were in 1953 or 1954, in the Tigrovaya Balka Nature Reserve.
Extinctions of the Turan tiger in the non-Soviet parts of its range, Afghanistan and Iran, were confirmed in 1964 and 1976, respectively. The last indigenous Soviet tiger probably disappeared in 1953 or 1954 in Tajikistan. On 10 January 1954, a tiger that apparently crossed into Turkmenia from Iran was killed on the Sumbar River near Kaine-Kasyr. The Director of the Kyrgyzstan Institute of Zoology, claims that a tiger was located on the Amu Darya delta in 1968, and other sources cite multiple sitings of a young tiger in June 1968 at the same location.
With the entrance into central Asia of Russians, special military hunting teams were formed to fight tigers, almost entirely destroying the tigers in a short period of time, although a large role in the driving away of these predators was played by the rapid agricultural reclamation and settlement of river valleys.
The total tiger population is estimated at between 4,400 and 7,700 individuals, including "unofficial" institutions such as circuses, there might be more tigers in captivity in the world now than in the wild.
In the early 1900s, there may have been 100,000 tigers, but the tiger population has declined by roughly 95% this century. Most of the remaining tigers are scattered in small isolated populations. At one point in the 1970's the tiger's numbers had dropped to about 4,000.
A World Bank funded mining expansion in the deciduous Sal forests of the Konar watershed (Thousand tiger region) in south-central Bihar state, to the east of the town of Hazaribagh, India, is threatening the habitat for around 30 per cent of the world's remaining wild tigers. The Konar watershed is situated in the north-eastern corner of what may be the largest connected tiger habitat on Earth, supporting perhaps as many as 1,500 tigers. The vital connecting corridors are stressed, but they are still functioning, and tigers are still using them. The 25 mines the World Bank is funding are to be distributed widely through the Thousand Tigers region. It is reasonable to expect that most of the other mines will also be expanded in the same area.
The bengal tiger inhabits tropical jungle, brush, marsh lands, and tall grasslands in fragmented areas of Bangladesh, Nepal, India, Bhutan, and Burma. Incidence: Only 3,000-4,000 Bengal tigers remain in the wild. 333 are in captivity, primarily in zoos in India. The IUCN Cat Specialist Group estimated 2,500 to 3,750 Bengal tigers in India in 1998. Also 93-97 tigers live in three protected areas in Nepal, 50-240 tigers are in four protected areas in Bhutan, about 360 tigers live in three protected areas in Bangladesh, and an unknown number of Bengal tigers remain in Myanmar.
Probably the least-known tiger subspecies as there are relatively few in zoos, P.t.corbetti has a broad distribution across most of Indochina, which includes southern China, Vietnam, Cambodia, Lao PDR, Thailand, Malaysia and eastern Myanmar. In Thailand, the center of the Indochinese tiger's range, earlier estimates of this subspecies status suggested a range of 400 to 600 individuals. In the early 1990s a survey of a number of sites suggested about 248 tigers were still left in Thailand's protected areas. According to the Thai Royal Forest Department (RFD), tigers are present in 42 protected areas in Thailand, distributed in 17 separate populations. The RFD suggests a potential total population of 439-595 tigers distributed across 44,295 km2 of habitat in Thailand. In 1995 there were about 43 Indochinese tigers in 10 zoos of Indochina and North America. An estimate in 1995 suggested as few as 200 tigers remained in Vietnam. However, several experts think that the actual number is lower - as few as 80. It is thought that only 1000 to 1700 of this subspecies remain.
The IUCN considers the Tiger as "Endangered". CITES lists the species as "Appendix 1".