YAKUTSK, November 28. /TASS/. Climate change forces polar bears to change their habitat and, on the contrary, helps brown bears to develop new territories. As a result, their habitats are overlapping, which can lead to interspecific conflicts and hybrid crossing, and this also increases risks for humans, the Ecofactor Ecology Center's Development Director Ilya Chernook told TASS.
In two expeditions to Chukotka (the Chukchi Peninsula) to study the Chukotka-Alaska polar bear population, scientists used long-range drones. The first expedition was in late August, 2022 - to the Chukchi Sea coast from Cape Schmidt to the village of Enurmino. The second expedition in September was on the Wrangel Island - where animals of the Chukotka-Alaska polar bear population have a "maternity hospital."
"We have used aircraft to survey comprehensively polar bear habitats on the Chukchi Sea coast," the scientist said. "We have found nine brown bears and a lot of their tracks. Brown bears are not typical for this territory, and their presence on the coast means that they begin competing with polar bears for food. Thus, the habitats of polar and brown bears begin to overlap."
When brown and polar bears meet, conflicts and hybrid crossing are possible, he continued. The appearance of brown bears on the coast brings risks, because, according to statistics, those animals are more aggressive and more dangerous to humans.
Scientists stress that in Yakutia and Chukotka polar bears have been coming more often to the mainland's coast. "We think this is due to changes in the ocean ice cover. The ice edge is retreating further to the north, thus the polar bear's food base - marine mammals - are changing the habitat. While following seals and walruses, polar bears are getting more often to the mainland. To be able to say how the population's number and distribution are changing, we need to have repeated regular studies," he added.
The polar bear is listed in the Russian Federation's Red Data Book and in the Red Data Book published by the International Union for Conservation of Nature and Natural Resources (IUCN). Its number is steadily decreasing. Among the main threats are poaching, the shrinking sea ice due to climate change, and the Arctic environment's pollution. Chukotka is home to the world's largest Chukotka-Alaska polar bear population.