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 population in southwest Primorye Province in the Russian Far East. In 2005, there were 331–393 adult and subadult 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 was declining. By 2015, the Siberian tiger population had increased to 480–540 individuals in the Russian Far East, including 100 cubs. A more detailed census revealed a total population of 562 wild Siberian tigers in Russia.