Tracking polar bears

Collecting information to help protect polar bears

Scientists learn about polar bears by observing them in their natural habitat. Radio collars are used to track their movements.

Only female polar bears can be tracked using radio collars. Male polar bears have necks that are wider than their head so the collars simply fall off.

Help us to understand how they travel

The collar sends signals via satellite that are used to plot the bear's path. From the data collected scientists can determine when a female enters a den, when she emerges with cubs and how far she travels each day. The tracking also enables scientists to map a polar bear's range to determine whether individuals travel vast distances or remain strictly within their home range. Over time this information reveals changes and adaptations. For example, in years when there is less sea ice, it will tell us where bears go and how they adapt.

Help us monitor health

When scientists fit a bear with a radio collar, they also collect important information about its health. Its length and weight are measured, samples of blood, fat, hair, and other tissues are taken to identify any toxic contamination, and its age is estimated.

How do you figure out a bear's age?

As a bear grows, a thin layer of bone, called cementum, is deposited each year in the teeth. By examining a thin slice of tooth under a microscope and counting the layers of cementum, the polar bear's age can be estimated in much the same way that tree rings reveal the age of a forest. To do this, a small tooth, located just behind the large canine teeth and of no use to the bear, is pulled. This information is vital for monitoring the health and condition of polar bears over time.