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.[1] By 2015, the Siberian tiger population has increased to 480–540 individuals in the Russian Far East, including 100 cubs.[2][3]