Polar bears in Norway’s Arctic are getting fatter and healthier, despite melting sea ice

A polar bear with her cub on a snowy beach in Svalbard, Norway on September 17, 2025. Credit: Magnus Martinsson/TT/Shutterstock via CNN Newsource

(CNN) — As the sea ice melts due to climate change, the trend of polar bears getting thinner and having fewer cubs has been well documented in areas such as Baffin Bay, a stretch of ocean between Greenland and Canada’s Baffin Island, and Hudson Bay in northeastern Canada.

A population of bears in Norway’s Arctic are bucking the trend, however, getting fatter and healthier even as the ice melts rapidly, according to a study published in the journal Scientific Reports on Thursday.

The Barents Sea area, off the northern coasts of Norway and Russia, has endured bigger temperature rises — up to 2 degrees Celsius, or 3.6 Fahrenheit, per decade in some parts — than other regions in the Arctic over the past few decades, the researchers from Norway, the United Kingdom and Canada noted.

The region has lost sea-ice habitat more than twice as fast as any other area where polar bears live.

Because of this, the researchers predicted that the bears would be leaner in the years when sea ice was less available.

Wild animals’ body condition usually gives early warning signs about the impact of environmental changes on their populations, according to the study.

Looking at the 27-year period between 1992 and 2019, they compared 1,188 body measurement records relating to 770 adult polar bears taken on Svalbard, a Norwegian-owned archipelago in the Barents Sea, with the number of ice-free days in the region.

The number of days the polar bears had to go without ice increased by approximately 100 days over that time period. Yet, after an initial decline in their body condition from 1995 to 2000, they actually became fatter and fitter in the two decades that followed.

So, while the ice was decreasing — reducing the bears’ ability to hunt for seals — their fat reserves were growing.

“The most likely explanation is that polar bears in Svalbard have so far been able to compensate for reduced access to sea ice by exploiting alternative foraging opportunities and by showing considerable ecological flexibility,” lead study author Jon Aars, a population geneticist and a senior researcher at the Norwegian Polar Institute, told CNN on Friday.

“In this region, bears have access (to) reindeer and eggs on land, walrus carcasses, and also harbour seals,” he continued.

An increasing number of bears had previously been observed spending more time on land during the summer, plundering birds’ nests in west Svalbard, and data had shown more adult females in east Svalbard spending more time in areas with bird colonies.

However, the researchers remain cautious.

“Importantly, maintained body condition does not mean that sea-ice loss has no effect,” Aars said. “Rather, it suggests that Svalbard bears have, up to now, been able to buffer some of the energetic costs associated with reduced ice.”

“This buffering capacity may rely on local conditions that are not present elsewhere in the Arctic and may not persist if sea-ice loss continues or accelerates,” he added.

Aars said the study “does not contradict the broader understanding that climate change poses a serious risk to polar bears. Instead, it underscores that climate impacts are complex and may involve temporary or partial compensation mechanisms.”

‘Only one piece of the puzzle’

Despite the bears’ apparent resilience to the impacts of a warming climate, the researchers only looked at one aspect of population health and did not assess other measures, such as overall population size.

While significant downward changes in survival and birth rates usually come after a decline in body condition, Aars said, “good body condition does not necessarily translate into stable reproduction, cub survival, or long-term population viability. Other demographic processes may already be negatively affected by sea-ice loss even if body condition appears maintained.”

He added that while the study looks at their past and present condition, it cannot predict how long the bears’ bodies will continue to be effective in compensating for a reduction in sea ice as climate change continues.

“These results are positive in the short term: the body condition of Svalbard bears showed little overall change during 1995-2019 despite substantial sea ice loss,” said animal biologist John Whiteman, chief research scientist at Polar Bears International and associate professor of biology at Old Dominion University in Virginia, in a statement shared with CNN on Friday.

However, Whiteman, who wasn’t involved in the Svalbard research, added that “body condition is only one piece of the puzzle” and fully understanding the factors driving this trend “requires continued monitoring, which emphasizes the importance of collecting long-term datasets.”

“Overall, while the big picture for conservation remains clear — polar bears need sea ice, which is disappearing due to climate change — this new study helps illustrate the substantial variation in how ice loss has affected bears thus far in different areas,” he added.

Amarachi Orie, CNN