The Siberian tiger (Panthera tigris altaica), also known as the Amur, Altaic, Korean, North Chinese or Ussuri tiger, is a subspecies of tiger which once ranged throughout Western Asia, Central Asia and eastern Russia, and as far east as Alaska during prehistoric times, though it is now completely confined to the Amur-Ussuri region of Primorsky Krai and Khabarovsk Krai in far eastern Siberia, where it is now protected. It is the biggest of the eight recent tiger subspecies and the largest living felid, attaining 320 kg (710 lb) in an exceptional specimen. Genetic research in 2009 revealed that the current Siberian tiger population is almost identical to the Caspian tiger, a now extinct western population once thought to have been a distinct subspecies.
