Steller sea lion
The southern end of Antsiferov is the site of one of five major Steller sea lion breeding rookeries (about 600 animals) on the Kuril Islands. Because of the absence of terrestrial predators, it is also the home of very dense colonies of northern fulmars and tufted puffins which nest in the hummocks along its slopes. Cliff-dwelling birds, such as kittiwakes and thick-billed murres are also abundant.