The Siberian Tiger, also known as the Amur tiger, is a tiger subspecies. In 2005, there were 331–393 adult and sub-adult Amur tigers in this region, with a breeding adult population of about 250 individuals. The population had been stable for more than a decade due to intensive conservation efforts, but partial surveys conducted after 2005 indicate that the Russian tiger population is declining.
The Siberian tiger is reddish-rusty, or rusty-yellow in color, with narrow black transverse stripes. The body length is not less than 150 cm (60 in), condylobasal length of skull 250 mm (10 in), zygomatic width 180 mm (7 in), and length of upper carnassial tooth over 26 mm (1 in) long. It has an extended supple body standing on rather short legs with a fairly long tail. It is typically 5–10 cm (2–4 in) taller than the Bengal tiger, which is about 107–110 cm (42–43 in) tall.
The skull of the Siberian tiger is characterized by its large size, and is similar to the skull of a lion, and differs in the structural features of the lower jaw and relative length of nasals. The facial region is very powerful and very broad in the region of the canines. The skull prominences, especially sagittal crest and crista occipitalis are very high and strong in old males, and often much more massive than usually observed in the biggest skulls of Indian tigers.
The ground color of Siberian tigers' pelage is often very pale, especially in winter coat. However, variations within populations may be considerable. Individual variation is also found in form, length, and partly in color, of the dark stripes, which have been described as being dark brown rather than black. The fur of the Siberian tiger is moderately thick, coarse and sparse compared to that of other fields living in the former Soviet Union. The summer coat is coarse, while the winter coat is denser, longer, softer, and silkier. The winter fur often appears quite shaggy on the trunk, and is markedly longer on the head, almost covering the ears. The whiskers and hair on the back of the head and the top of the neck are also greatly elongated. The background color of the winter coat is generally less bright and rusty compared to that of the summer coat. Due to the winter fur's greater length, the stripes appear broader with less defined outlines. The summer fur on the back is 15–17 mm (0.59–0.67 in) long, 30–50 mm (1.2–2.0 in) along the top of the neck, 25–35 mm (0.98–1.38 in) on the abdomen, and 14–16 mm (0.55–0.63 in) on the tail. The winter fur on the back is 40–50 mm (1.6–2.0 in), 70–110 mm (2.8–4.3 in) on the top of the neck, 70–95 mm (2.8–3.7 in) on the throat, 60–100 mm (2.4–3.9 in) on the chest and 65–105 mm (2.6–4.1 in) on the abdomen. The whiskers are 90–115 mm (3.5–4.5 in).
Key habitats for the Amur tiger are Korean pine broadleaf forests with a complex composition and structure. The faunal complex of the region is represented by a mixture of Asian and boreal life forms.
Prey species include Manchurian wapiti, musk deer, goral and smaller prey like hares, rabbits, pikas and salmon.