The Bengal tiger (Panthera tigris tigris) is the most numerous tiger subspecies. Its populations have been estimated at 1,706-1,909 in India, 440 in Bangladesh, 124-229 in Nepal and 67-81 in Bhutan. Since 2010, it has been classified as an endangered species by the IUCN. The total population is estimated at fewer than 2,500 individuals with a decreasing trend, and none of the Tiger Conservation Landscapes within the Bengal tiger's range is large enough to support an effective population size of 250 adult individuals.
Bengal is traditionally fixed as the typical locality for the binomial Panthera tigris, to which the British taxonomist Pocock subordinated the Bengal tiger in 1929 under the trinomial Panthera tigris tigris. It is the national animal of both India and Bangladesh. 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.
Male Bengal tigers have an average total length of 270 to 310 cm (110 to 120 in) including the tail, while females measure 240 to 265 cm (94 to 104 in) on average. The tail is typically 85 to 110 cm (33 to 43 in) long, and on average, tigers are 90 to 110 cm (35 to 43 in) in height at the shoulders. The average weight of males is 221.2 kg (488 lb), while that of females is 139.7 kg (308 lb).
The smallest recorded weights for Bengal tigers are from the Bangladesh Sundarbans, where adult females are 75–80 kg (170-180 lb). The white tiger is a recessive mutant of the Bengal tiger, which is reported in the wild from time to time in Assam, Bengal, Bihar and especially from the former State of Rewa. However, it is not to be mistaken as 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. Two tigers shot in Kumaon and near Oude at the end of the 19th century allegedly measured more than 12 ft (370 cm). But at the time, sportsmen had not yet adopted a standard system of measurement; some would measure between pegs while others would round the curves.