Svalbard Polar Bears Has Better Body Condition Now Than 25 Years Ago

Although the polar bear spends less time on the ice throughout the year than before, it has better body condition than 25 years ago.

The researchers mapped the body condition of polar bears in Svalbard in the spring over a period from 1995 to 2019 in a study that was recently published in Scientific Reports, issued by Nature.

The first author of the study, senior researcher Jon Aars at the Norwegian Polar Institute, says these are surprising findings.

"If we had been asked 25 years ago about the consequences of the polar bear having on average two months less on the ice during a year, the expectation would have been leaner animals, reduced reproduction, and the start of a decline in the population. Instead, we see that they are in better condition."

He adds that the most likely explanation is that polar bears are able to find food on land to an increasing degree.

"They eat more reindeer, eat walrus carcasses, and they make use of eggs, birds, and ringed seals," says Aars.

"This seems to have enabled the bears to maintain - and even improve - their body condition, even though they spend much more time on land than before," says Aars.

This is how polar bears have maintained and even improved their body condition, despite spending much more time on land than before.

The development, however, differs from other places in the Arctic, where polar bears have become leaner.

"The development also means that polar bears increasingly affect terrestrial ecosystems, especially bird colonies, and that they become a more important part of the terrestrial ecosystem on Svalbard than before," says Aars.

Critical threshold

The researcher says it is still likely that polar bears on Svalbard will also become thinner in the long term, provided that sea ice continues to disappear.

"Polar bears depend on sea ice for a minimum period each year, but we still do not know where this critical threshold lies. So far, there are no signs of a dramatic decline in survival or reproduction," emphasizes Aars.

Monitoring body condition remains important because it serves as an early warning system; changes can be the first signs that more serious consequences are imminent.