Population Studies

It's cold. It's difficult. It's dangerous. But what a thrill to work with wild polar bears. Scientists say that the first polar bear of the season still takes their breath away, even after decades of working in the Arctic.

Why take population counts and track polar bears? They help scientists understand how the bears are faring. Long-term studies are especially important for understanding trends and for ringing alarm bells as necessary.

Data from the Southern Beaufort Sea population, for example, helped lead to the U.S. decision to list the polar bear as a threatened species. The scientists collect data on:

• Size and health of the population

• Number of bears in each age and sex class

• Movement patterns of the bears and how they're responding to declining sea ice

Scientists in the field place satellite collars on a select number of bears every fall in certain areas. The technology lets research teams follow polar bears across the Arctic from the comfort of a warm office thousands of miles away. Especially in winter, we have no other practical means of learning about polar bears during 24 hours of darkness, when Arctic blizzards howl and temperatures plunge. 

The collars allow scientists to:

• Track movements and habitat use

• Determine hunting patterns

• Measure the total distance traveled

• Map home range areas

• Collect data on cub survival rates

The collars are designed to fall off on their own in about 14 months. Interesting fact: only female bears can wear collars. A male polar bear's neck is wider than its head, so the collar just slips off!

You can follow some of the satellite-collared polar bears on our Polar Bear Tracker Map.

Tracking technology continues to improve, so scientists are developing new collar designs as well as alternative tracking methods. These include a small "Burr on Fur" design that we developed in partnership with 3M and tested with partners. It allows scientists to attach a small tracking device to a polar bear's fur.

The stick-on tags don't deliver as much data as collars—but they provide scientists with a way to track adult males and subadult bears, which will add to our understanding of polar bear ecology.

Other innovations include aerial surveys, which will let researchers take population counts by air. Polar Bears International helped fund studies to refine this approach because many parts of the Arctic are so remote that scientists can only make rough estimates about how many polar bears are there. In fact, of the 20 polar bear populations, 10 are classified as data-deficient.

Although capture efforts give us more detailed information on a population's health and movement patterns, aerial surveys will allow us to take a quick snapshot of how many bears there are in populations that we know little about.

Barents Sea

The Barents Sea polar bear population, shared between Norway and Russia, has experienced the fastest loss of sea ice habitat among the 20 recognized populations—a trend predicted to continue. As movements, distribution, prey, and denning locations shift, so will behavioral ecology and demography. This project will help researchers better understand how rapid sea ice changes impact polar bear health, reproduction, and movements, and can improve our understanding of the role genes play in population viability, a critical component in the species’ long-term conservation.

Project partners include the Norwegian Polar Institute and San Diego Zoo Wildlife Alliance.

Hudson Bay

Sea ice is critical to the polar bears’ survival, primarily as a platform for hunting seals. The ice continues to change dramatically but we don’t fully understand the impacts. This study looks directly at polar bears’ on-ice ecology during their prime spring feeding period. Using tracking and mark-recapture methods, comprehensive sampling of bears and their seal kills, and remote sensing images of sea ice, we can gain insights into polar bear movements, reactions to changing sea ice patterns, distribution, health, predation of seals, and their essential habitats.

Project partners include Environment and Climate Change Canada, Manitoba Conservation and Sustainable Development and the University of Alberta.

Wrangel Island

This collaborative study, now on pause due to the war in Ukraine, focused on Russia’s Wrangel Island, a critical resting and denning location for the data-deficient Chukchi Sea polar bears. Using ground-based observations and non-invasive genetic samples (hair traps), researchers were examining gene flow, diversity, and population dynamics to improve our understanding of how these bears fit into global polar bear diversity. Researchers were also working to improve our understanding of how Wrangel Island’s bears were handling the effects of increasing industrial activities and longer ice-free seasons due to climate warming.

Project partners included the University of Washington, the Wrangel Island Nature Reserve, All-Russian Research Institute for Environment Protection and the U.S. Fish and Wildlife Service.