The power of observation

Polar bear science is pretty high-tech these days. But as ERIC V. REGEHR writes, new doesn’t always mean better—and researchers have gleaned some astounding insights into polar bear behaviour just by analyzing data collected during decades of close observation.

When it comes to studying polar bears, science has come a long way. Satellites can now provide daily pictures of the sea ice that bears depend on. Researchers can identify individual animals from the DNA left in their footprints and figure out what they eat by analyzing single strands of hair. GPS tracking devices that once came as big radio collars are now smaller and lighter, providing near real-time movement information.

But while these and other technological advances have taught us a lot, a recent project reminded me that polar bears still have some secrets that can only be unlocked the old-fashioned way: by watching them in the wild.

Dr. Ian Stirling, an adjunct professor at the University of Alberta and research scientist emeritus with Environment and Climate Change Canada, had this fact firmly in mind when he pitched a tent on a bluff and started observing wild polar bears in Radstock Bay, Nunavut, Canada in 1970. More than 50 years later, he hasn’t forgotten it. His foresight led to one of the most interesting collaborations of my career: working with him and others to analyze thousands of hours of behavioural data collected from 1973 to 1999 while watching bears, well, just be bears.

A treasure trove of bear information

Each year in the camp, Dr. Stirling and other members of the team recorded everything the bears did—minute by minute, glasses fogged up, fingers freezing. This initiative produced such rich and unique information that, when the database was recently digitized for the first time, the hardest part was figuring out which analyses to start with.

We decided to focus on animal welfare. We compared the behaviour of a few bears that had been temporarily put to sleep for research with that of others that had not been disturbed. Our findings, published in the journal Arctic, show that bears sleep more and hunt less for the first 48 hours after immobilization, after which their behaviour returns to normal. But that wasn’t all. We also discovered that several bears killed seals within 24 hours of immobilization, that adult males and adult females without cubs go days without hunting in the spring because they’re too busy mating, and that polar bears hunt more under a full moon, even during the 24-hour daylight of the Arctic summer.

Dr. Stirling’s decades of observational data aren’t just a neat slice of natural history—they’re a treasure trove of ecological information that is relevant to the challenges now facing the species, including the number one threat of climate warming

– Eric V. Regehr, research scientist

Today, Dr. Stirling’s decades of observational data aren’t just a neat slice of natural history—they’re a treasure trove of ecological information that is relevant to the challenges now facing the species, including the number one threat of climate warming. So now, we’re digging more deeply into the data to better understand what the future might hold. How many hours does a mother bear need to nurse her cubs each day? How many seals does a massive 600 kg male need to eat each week? And how are these and other things changing as the sea ice melts more each year and bears are forced to spend increasing stretches of time on land?

I hope this collaboration lasts a long time. Observational studies may not be flashy, but they’re much more than a throwback to earlier times. Polar bears are intelligent and individualistic animals. They have adapted to one of the harshest environments on Earth in amazing ways. Some of the things we’re learning—like how many days a polar bear will hunt patiently before killing a seal—are hard to grasp using only your imagination. You need to see them with your own eyes.

For me, the project has been a welcome reminder that in order to do the best science we can, sometimes we need to slow down and take the time to observe polar bears on their own terms.