STRUCTURE OF THE WINTER FAUNA OF MAMMALS IN THE SEAS OF NORTHEASTERN PALEARCTIC OF RUSSIA

Abstract

The ecological patterns of structure formation and spatial differentiation of the winter fauna of mammals in the seas of the northeastern Palearctic are analyzed. The method of aviation route surveys in a 1 km wide zone was applied. Aerial surveys in the end of 1987-1988 winter period covered the Bering, Chukchi, East Siberian Seas, and the eastern part of the Laptev Sea. The recorded species of mammals (n = 7) are ecologically associated with open sea areas, sea ice, continental and island coasts, and continental tundra. The winter fauna of mammals in the seas of the northeastern Palearctic accounts for 23% of the total mammalian fauna of the region; pinnipeds and cetaceans predominate in terms of the number of species. The similality of the winter fauna of mammals in the Arctic Ocean and the Northern Pacific is 36%. Most of the mammals were observed on the leads in the contact zones between different types of ice or in iceholes among the ice of autumn formation. Polar bears were most often observed near the Wrangel Island, beluga whales - to the east and northeast of the Navarin Cape, walruses - to the south of the Providence Bay. The average density of the winter population of mammals in the surveyed seas of the Northeastern Palearctic is 6.2 individuals/100 km². Walruses, beluga whales, and ringed seals predominate in the population, totaling 94% of the animal numbers.