A Norwegian polar bear population is going against the global trend by getting heavier and staying in good shape even as the sea ice around them melts. This is happening in one of the fastest-warming parts of the world.
Against the odds in a world that is getting warmer fast Arctic
Research from places like Baffin Bay and Hudson Bay has been telling a sad story for years. Fewer polar bears and thinner bears have meant fewer cubs and worse chances of survival.
The Barents Sea, which is between Norway and Russia, should follow the same pattern. In the last few decades, some parts of this area have warmed by up to 2°C per decade, making it one of the Arctic’s fastest-heating areas.
The sea ice here is melting away more than twice as fast as it is in other areas where polar bears live. That loss takes away bears’ main way to hunt seals, which are high in calories and help them build up fat reserves.
Researchers thought that bears would be thinner in years with less ice. Instead, the adult bears in Svalbard got heavier over time.
The new study, which came out in the journal Scientific Reports, is about adult polar bears that live near Svalbard, a Norwegian archipelago in the Barents Sea. For more than 27 years, from 1992 to 2019, scientists carefully measured body size and health.
What the data from the long term show
The team looked at 1,188 body measurements from 770 adult polar bears and compared them to the number of days each year when the area was free of ice.
Place of study: Svalbard, in the Barents Sea
Years: 1992–2019 (27 years)
770 adults were tested on bears.
Measurements taken: 1,188 records of body condition
Change in days without ice: about +100 days over the course of the study
The data fit what we thought at first. From the mid-1990s to around 2000, the bears’ health got worse as the sea ice melted.
Then something that wasn’t expected happened. As the number of days without ice grew, the bears’ health stabilized and, on average, got better over the next twenty years.
Even though the sea ice was getting smaller and it was getting harder to hunt seals, Svalbard’s polar bears generally got fatter and looked healthier.
The bears were doing better on the scales at the end of the study than models had thought they would. This made me wonder: what are they doing differently?
How polar bears are changing in Svalbard
Going from hunting ice to taking advantage of land
People often think of polar bears as specialists that only hunt on sea ice. Scientists are seeing a different side of them in Svalbard.
Researchers say that more bears, especially females, are spending more time on land during the summer. They are expanding their menu instead of waiting for seals on the ice.
- Bears in this area can find a number of other food sources on and near land:
- Reindeer eating grass on the tundra
- Eggs and chicks from colonies of seabirds
- Walrus bodies washed up on the beach
- Common seals live near the coast.
Scientists have seen bears break into bird nests in western Svalbard and spend more time near dense bird colonies in the east. At least for now, these opportunistic meals seem to be helping them keep or even build up their fat stores.
The fact that polar bears can change their feeding habits in Svalbard shows that they may be more adaptable than people used to think, as long as the conditions are right.
What makes this area different from other Arctic hotspots
The Barents Sea is unique because it is warming and losing ice so quickly. But Svalbard also has things that many other polar bear areas don’t have.
F
| Factor | Svalbard (Barents Sea) | Many other polar-bear regions |
|---|---|---|
| Access to land prey | Reindeer, bird colonies, carcasses | Often limited or less abundant |
| Coastal topography | Complex coastline, islands and cliffs for seabirds | More open coasts with fewer concentrated colonies |
| Sea ice loss rate | Very rapid, strong seasonal shifts | Variable, often slower in past decades |
| Human management | Strict protections and hunting bans | Regulations differ widely by region |
A sign of hope, not a way out of climate change
Even though the body’s condition is getting better, the scientists involved are careful not to overstate the result. They stress that just because a polar bear is fat doesn’t mean it’s safe.
Being in good shape doesn’t mean that reproduction will be stable, cubs will survive, or the population will be viable in the long term.
Important parts of the puzzle are still missing. This study primarily examined the physical condition in adults. It didn’t look at the total number of people, the birth rate, or how many cubs are becoming adults.
For many species, survival or breeding success goes down after their body condition gets worse. In Svalbard, the opposite could be true: adult bears may still look strong, but their reproduction may be slowly going down.
Independent experts say that one good sign can hide deeper problems. They say that to really understand what’s going on, we need to keep track of individual bears, the number of cubs, and deaths over a long period of time.
What “body condition” really means
When scientists look at wildlife, they often use the term “body condition,” but it can be hard to understand what they mean. In real life, it means the animal’s overall energy levels and health.
Researchers usually look at the following things when studying polar bears:
Weight and length of the body (to see how heavy a bear is for its size)
Fat stores that can be seen, especially on the hips and shoulders
Tone of muscles and overall shape
Age and sex, which affect how things change naturally
A bear that is in good shape has enough fat to last through times when food is hard to find and to have babies. Those reserves are very important for a pregnant woman. She might spend months in a den giving birth and nursing her cubs without eating outside.
When the health of a population’s bodies gets worse, it often means that the environment is under more stress, like losing habitat or prey. For Svalbard, the surprise is that this early warning sign isn’t flashing red yet, even though a lot of ice has melted.
What might happen to Svalbard’s bears in the future
The study only shows how bears have reacted so far. It doesn’t say how long they can keep paying as the weather gets warmer.
Researchers list a few possible paths:
Short-term resilience: Bears keep eating land-based food to make up for some of the loss of seal hunting, which keeps their bodies in relatively good shape for a while.
Long-term decline: As ice-free seasons get longer, land resources may not be able to make up for the energy gap, which could lead to lower survival and reproduction rates.
Some groups of bears, like those that live near rich bird cliffs or carcass sites, may do better than others that live in more remote or barren areas.
There is also a chance that things will get worse. If polar bears eat more reindeer or bird colonies, that pressure can change the ecosystems where they live, which could mean fewer of those food sources in the future.
What this means for discussions about climate change and conservation
The Svalbard results are in the middle of a heated discussion about the effects of climate change. Pictures of polar bears that are starving have become strong symbols of climate change. Some people might misuse a study that says some bears are getting fatter to downplay the risks.
The researchers themselves say that sea ice is still very important for polar bears and that ice is still melting because of global warming caused by people.
The overall situation in the Arctic still shows that many polar bear populations are losing habitat and becoming more stressed. Svalbard appears to be an example of short-term resilience in a favourable setting, not an escape from climate pressure.
The study shows how important local context is for planning conservation efforts. People who have access to a variety of food sources and strong protections may be able to handle things better for a while. Others, especially those who live in flatter, less productive areas, might not have that choice.
It also shows how important it is to do fieldwork over a long period of time. If we hadn’t taken measurements over and over for almost thirty years, we wouldn’t have noticed this surprising change in body condition. That kind of dataset helps separate brief fluctuations from real trends, and can guide decisions on protected areas, shipping routes and tourism limits in the Arctic.
