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Polar-brown bear hybrid may develop in Yakutia's north, expert says

It is reported that scientists explain such hybrids by the climate changes

YAKUTSK, November 7. /TASS/. A hybrid of a brown and a polar bear may develop in Yakutia's north due to the changing habitat areas of those mammals, Director of the Institute for Biological Problems of Cryolithozone (the Russian Academy of Sciences' Siberian Branch) Innokentiy Okhlopkov told TASS.

Polar bears are the largest land predators on the Earth. They spend the biggest part of life at sea among drifting ice. According to the World Wildlife Fund, the Arctic ice cover has shrunk by more than 30% in recent years, and due to this the polar bear population may decrease by two-thirds very soon.

"Brown bears are moving into the tundra. Brown bears have been seen in the lower reaches of the Kolyma River (Yakutia's Arctic zone - TASS), where polar bears live," the scientist said. "Brown bears have been seen, for example, in the Anabar District. It is likely that in the future there will be hybrids of polar and brown bears."

A similar case was recorded in Canada. In 2006, an unusual polar bear was seen in the Northwest Territories: it had brown marks on the fur, and its muzzle was shaped untypically. Hunters shot the animal, and results of DNA tests confirmed what scientists had guessed: it really was an ursid hybrid of a polar bear and a grizzly. In 2010, another bear was shot in the same Arctic region of Canada. The animal turned out to be a result of crossing in the next generation - a hybrid mother and a grizzly father.

Scientists explain such hybrids by the climate changes. According to the US Vanderbilt University, the sharp weather changes in the polar Arctic lead to a reduction in the area of sea ice, that is, the hunting grounds of polar bears. On the other hand, for the same reason, the hunting territories available to grizzlies have been expanding northbound. Thus, their habitats begin to overlap.

Climate changes

Other species, typically living in the taiga, such as wolverines and foxes, have become more active in the tundra, said Maria Vladimirtseva, an expert at the Institute of Biological Problems of Cryolithozone. Noticeable changes have been found also in the tundra vegetation cover.

Studies find that taiga bird species in Yakutia have been expanding their habitats in the northern direction. Scientists refer this phenomenon to the climate changes, among other aspects. "The warming recorded by climate experts is reflected in the northward movement and increase in numbers of some invertebrates that are part of the bird food supply, as well as in the changing vegetation. These changes in the Arctic ecosystems create conditions for some bird species to expand their ranges in the northern direction," she said.

The process of occupying new nesting sites within a territory can demonstrate the Northeast Asia tundra communities are insufficient, and it may be seen as the tundra biota's possible reaction to the climate warming, the ornithologist added.

The Institute of Permafrost Studies (the Russian Academy of Sciences' Siberian Branch), has analyzed data from 52 weather stations in Yakutia to find that over recent 50 years the average annual air temperature across the region has grown by 1.1 to 3.4 degrees. This warming happens unevenly in time and space and is caused mainly by the warming during winter seasons. The contribution of summer seasons is less significant.

Earlier, scientists have reported the nesting expansion of the Asian dowitcher into Siberia's taiga - to Yakutia's west. Ornithologists predict this rare representative of the dowitcher family will spread to the region's north-east - into the Arctic regions. The steppe birds have been flying to Yakutia in pairs since 2018. First chicks were found in 2019. Since that time, the species has begun the northeast expansion. In 2021, the birds were seen in the watershed of the Vilyu and the Lena Rivers.

Population studies

According to the Institute, Yakutia is home to two polar bear populations - Laptev and Chukchi-Alaska. To preserve the number of Arctic animals, in July 2020, the Bear Islands Nature Reserve was created in Yakutia's Nizhnekolymsky District. The nature reserve was organized under the Ecology national project. The reserve covers the Kolyma River delta, the tundra landscapes of the Indigiro-Kolyma lowland and the Medvezhye Islands archipelago with the adjacent water area of the East Siberian Sea.

The reserve preserves rare and endangered species of animals, birds and their habitats. The Medvezhye Islands archipelago is the main location for polar bears' ancestral dens in Yakutia.

Scientists conduct autumn and spring monitoring sessions, using aircraft. In October, during an autumn air monitoring, they found about 60 polar bears, including about 30 individuals on the archipelago islands.

Polar bears are listed in the International Red Date Book and in the Red Data Book of Russia. Specialists say, the global population is between 22 and 31 thousand animals. The population has been decreasing steadily. The main threats are poaching, reducing areas of sea ice due to the climate changes, and the Arctic environment pollution.