Franz Josef Land and snow bunting. Some ivory gulls, little auks and Brünnich's guillemots opt to spend the winter on the islands. The polar bear population of Franz Josef Land lies within the Barents Sea subpopulation, which also includes polar bears inhabiting Svalbard and the western coast of Novaya Zemlya. In 2004, the Barents Sea subpopulation was estimated at 2,650. There is also a population of Arctic fox, which typically have their territories near seabird habitats. Being declared as a marine mammal sanctuary, the island has rich biodiversity of rare marine mammals. Three species of seals habit the archipelago. Harp seal is the
History of Franz Josef Land the southern and central parts of the archipelago had been explored. At the time there was a presumption that a large landmass, tentatively called Petermann Land, stretched northwards, possibly all the way to the pole. To the west another landmass was expected, Gillis Land, which it was expected might reach as far as Svalbard. Frederick George Jackson hoped to exploit the previous expeditions' experience with overwintering to launch an expedition to explore the northern parts of the island group. To prepare for the trip, in 1893 he took an expedition to Yugorsky Strait and Vaygach Island, south of Novaya Zemlya.