There were once eight subspecies of tigers. Today, three are extinct. Three others are critically endangered, including the Amur tiger.
It's estimated that only 350 to 450 Amur tigers survive in the wild. Besides being reduced in number, their range has been reduced. Once, they lived throughout much of Siberia and surrounding areas, and for this reason they were often called Siberian tigers. Today, with their reduced range, they're no longer found in Siberia or called by that name. (Their "new" name comes from the Amur River, which flows through the middle of their current, reduced range in Russia.)