North Pacific right whale
Bears, foxes, otters, and sables are numerous, as are reindeer in the north, and musk deer, hares, squirrels, rats, and mice everywhere. The bird population is mostly the common east Siberian, but there are some endemic or near-endemic breeding species, notably the endangered Nordmann's greenshank ("Tringa guttifer") and the Sakhalin leaf warbler ("Phylloscopus borealoides"). The rivers swarm with fish, especially species of salmon ("Oncorhynchus"). Numerous whales visit the sea coast, including the critically endangered Western Pacific gray whale, for which the coast of Sakhalin is the only known feeding ground. Other endangered whale species known to occur in this area are the North Pacific right whale, the bowhead whale, and the beluga whale.