The tiger is the largest member of the cat family, with the Siberian tiger weighing as much as 360 kg (790 lb). Although it is found in a variety of habitats, the tiger always requires dense vegetative cover, an adequate supply of large ungulate prey, and access to a reliable source of water. The principal prey of the tiger consists of various species of deer and wild pigs, usually in the 50 - 200 kg (110 - 440 lb) range. These include sambar, chital, swamp deer, red deer, Timor deer and wild boar. It will also take young elephants and rhinos and smaller species such as monkeys, birds, reptiles and fish.

Tigers are generally diurnal or crepuscular where they are undisturbed, but they become nocturnal in disturbed habitats or near human settlements. They do not readily cross large open areas. Although tigers are usually solitary (except for females with cubs), males and females exhibit a high degree of social tolerance towards one another. A male tiger usually establishes a territory that does not overlap with the territories of other males but does overlap the territories of 2 - 3 females (up to 7). Females establish territories that generally (but not always) do not overlap each other. The range of an individual tiger can vary from 50 sq km (20 sq mi) in an area with high prey densities (e.g. some reserves in India) to 4000 sq km (1500 sq mi) in Siberia.

The tiger formerly occurred from Turkey across southern Asia and most of China, to the Soviet Far East. The Southeast Asian range included Peninsular Malaysia, Singapore, Sumatra, Java and Bali. But the abundance and distribution of tigers has diminished substantially since the beginning of the 20th century. 3 of the 8 subspecies of tiger, the Bali, Caspian and Javan tigers, have become extinct since the 1950's. Currently, the tiger occurs only in scattered populations from India to Vietnam and in Indonesia (Sumatra), the Russian Far East, and possibly in China and North Korea. The tiger is extinct in most of its former range.

Commercial poaching (especially to obtain various parts of the tiger's body for Oriental medicine), a declining prey base, and loss of habitat are the principal threats to the tiger at present.