In the frozen wilderness of Svalbard, Norway, a mother polar bear and her cubs emerge from their snow-covered den. The scene is quiet, almost magical—a special moment in one of the harshest environments on Earth. For nearly a decade, researchers have been waiting to witness this very moment, captured for the first time in stunning detail through remote camera traps.
Nothing like this has been seen before since polar bear moms build their dens under the snow in highly remote areas in the Arctic. Wildlife enthusiasts are in for a treat — and it’s right on time for International Polar Bear Day.
By combining satellite tracking collars with remote cameras, scientists have uncovered new insights into how polar bear families navigate their most vulnerable period—the months spent hidden beneath the snow.
“Polar bear mothers are having increasing difficulties reproducing due to climate-driven changes, and are likely to face further challenges with the expansion of the human footprint in the Arctic,” says Dr. Louise Archer, lead author of the study and a Polar Bears International Postdoctoral Fellow at the University of Toronto Scarborough. “Every den we monitored had its own story, every data point adds to our understanding of this crucial time and supports more effective conservation strategies.”
The Fragile First Steps of Polar Bear Cubs
Polar bear cubs are born blind, hairless, and weighing just half a kilogram. For the first few months of their lives, they rely entirely on their mothers, nursing on milk that is 31% fat. By the time they emerge from the den in spring, they can weigh up to 10 kilograms—a remarkable transformation. But this period is fraught with danger. Less than half of all cubs survive to adulthood, making the denning phase critical to the species’ survival.
Unprecedented footage now shows that polar bear families in Svalbard are emerging from their dens earlier than previously recorded—around March 9th. This shift in timing could have serious consequences. “Changing the timing of denning could potentially jeopardize cub survival,” explained the researchers. “Cubs have less time to develop before venturing further afield to the sea ice.”
The cameras also captured surprising variability in denning behavior. Some bears emerged for less than a minute before retreating back inside, while others stayed out for hours. On average, polar bear families remained near their dens for 12 days after emergence, though this ranged from just two days to over a month. In some cases, mothers even moved their cubs to new dens—a behavior rarely documented before.
This demonstration of high-tech wildlife monitoring that combines satellite collars with remote cameras could soon be scaled. It allows researchers to monitor dens with unprecedented precision. The collars track the bears’ location, temperature, and activity, while the cameras provide fine-scale details about their behavior.
“Studies including observational data at polar bear den sites have been few, and this study thus contributes significantly to our knowledge about denning ecology,” says Dr. Jon Aars, Senior Researcher at the Norwegian Polar Institute. “The data from satellite collars and cameras allow us to see how changes in activity and temperature correspond with behavior. This is of great value.”
A Call to Protect the Arctic’s Future
The research comes at a critical time. As the Arctic warms and human activity expands, polar bears face mounting threats. Sea ice—their primary hunting ground—is disappearing, forcing them to spend more time on land. This makes undisturbed denning areas more important than ever before.
According to NASA, Arctic sea ice is now shrinking at a rate of 12.2% per decade, compared to its average extent during the period from 1981 to 2010. Over the past 30 years, the oldest and thickest ice in the Arctic has declined by a stunning 95%.
Whether it’s oil drilling, shipping, or tourism, any activity near denning sites could have devastating consequences for cub survival.
By understanding the hidden lives of polar bear families, scientists can better advocate for their protection. And for the cubs now nestled in dens across the Arctic, these insights could mean the difference between life and death.
The findings appeared in the Journal of Wildlife Management.
