Сивуч
Raikoke is one of five major Steller sea lion rookeries on the Kuril Islands and in the spring and summer it is home to one of the largest northern fulmar aggregations on the Kurils; crested and parakeet auklet, pigeon guillemot, and black-legged kittiwake also nest on the island. Captain Henry James Snow reported that in 1883 some 15,000 northern fur seals inhabited the island. However, by the 1890s only "a few scores" were recorded captured there, almost certainly due to overexploitation by fur hunters. Currently no fur seals reproduce on Raikoke.