The Bengal tiger is a population of the Panthera tigris tigris subspecies and the nominate tiger subspecies. It ranks among the biggest wild cats alive today. It is considered to belong to the world's charismatic megafauna.
The tiger is estimated to have been present in the Indian subcontinent since the Late Pleistocene, for about 12,000 to 16,500 years. Today, it is threatened by poaching, loss and fragmentation of habitat, and was estimated at comprising fewer than 2,500 wild individuals by 2011. None of the Tiger Conservation Landscapes within its range is considered large enough to support an effective population of more than 250 adult individuals.
The Bengal tiger's historical range covered the Indus River valley until the early 19th century, almost all of India, Pakistan, southern Nepal, Bangladesh, Bhutan, and southwestern China. Today, it inhabits India, Bangladesh, Nepal, Bhutan, and southwestern China. India's tiger population was estimated at 2,603–3,346 individuals by 2018. Around 300–500 individuals are estimated in Bangladesh by 2015, 355 in Nepal by 2022, and 90 individuals in Bhutan by 2015.
The Bengal tiger's coat is yellow to light orange, with stripes ranging from dark brown to black; the belly and the interior parts of the limbs are white, and the tail is orange with black rings. The white tiger is a recessive mutant, which is reported in the wild from time to time in Assam, Bengal, Bihar and especially in the former State of Rewa. However, it is not an occurrence of albinism. In fact, there is only one fully authenticated case of a true albino tiger, and none of black tigers, with the possible exception of one dead specimen examined in Chittagong in 1846. Fourteen Bengal tiger skins in the collection of the Natural History Museum, London have 21–29 stripes. Another recessive mutant is the golden tiger that has a pale golden fur with red-brown stripes. The mutants are very rare in nature.
The greatest skull length of a tiger is 351 mm (13.8 in) in males and 293 mm (11.5 in) in females. It has exceptionally stout teeth. Its canines are 7.5 to 10 cm (3.0 to 3.9 in) long and thus the longest among all cats.
In 1982, a sub-fossil right middle phalanx was found in a prehistoric midden near Kuruwita in Sri Lanka, which is dated to about 16,500 years ago and tentatively considered to be of a tiger. Tigers appear to have arrived in Sri Lanka during a pluvial period, during which sea levels were depressed, evidently prior to the last glacial maximum about 20,000 years ago. The tiger probably arrived too late in southern India to colonise Sri Lanka, which earlier had been connected to India by a land bridge. Results of a phylogeographic study using 134 samples from tigers across the global range suggest that the historical northeastern distribution limit of the Bengal tiger is the region in the Chittagong Hills and Brahmaputra River basin, bordering the historical range of the Indochinese tiger. In the Indian subcontinent, tigers inhabit tropical moist evergreen forests, tropical dry forests, tropical and subtropical moist deciduous forests, mangroves, subtropical and temperate upland forests, and alluvial grasslands. The latter habitat once covered a huge swath of grassland, riverine and moist semi-deciduous forests along the major river system of the Gangetic and Brahmaputra plains, but has now been largely converted to agricultural land or severely degraded. Today, the best examples of this habitat type are limited to a few blocks at the base of the outer foothills of the Himalayas including the Tiger Conservation Units (TCUs) Rajaji-Corbett, Bardia-Banke, and the transboundary TCUs Chitwan-Parsa-Valmiki, Dudhwa-Kailali and Shuklaphanta-Kishanpur. Tiger densities in these TCUs are high, in part because of the extraordinary biomass of ungulate prey.
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