The Siberian tiger (Panthera tigris altaica), also known as the Amur tiger, is a tiger subspecies inhabiting mainly the Sikhote Alin mountain region with a small subpopulation in southwest Primorye province in the Russian Far East. In 2005, there were 331–393 adult-subadult Amur tigers in this region, with a breeding adult population of about 250 individuals. The population has 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.