The Siberian tiger (Panthera tigris tigris), also called Amur tiger, is a tiger population inhabiting mainly the Sikhote Alin mountain region in southwest Primorye Province in the Russian Far East. The Siberian tiger once ranged throughout Korea, north-eastern China, Russian Far East, and eastern Mongolia. In 2005, there were 331–393 adult and subadult Siberian tigers in this region, with a breedingadult 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. An initial census held in 2015 indicated that the Siberian tiger population had increased to 480–540 individuals in the Russian Far East, including 100 cubs. This was followed up by a more detailed census which revealed there was a total population of 562 wild Siberian tigers in Russia.
Results of a phylogeographic study comparing mitochondrial DNA from Caspian tigers and living tiger subspecies indicate that the commonancestor of the Siberian and Caspian tigers colonized Central Asia from eastern China, via the Gansu− Silk Road corridor, and then subsequently traversed Siberia eastward to establish the Amur tiger population in the Russian Far East. The Caspian and Siberian tiger populations were the northernmost in mainland Asia.
The Siberian tiger was also called Manchurian tiger, Korean tiger, and Ussurian tiger, depending on the region where individuals were observed.