Dr. Todd Atwood and the Future of Polar Bears

Effects of climate change become increasingly urgent, they’ve taken a close look at arctic sea ice...

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The Wild Life-Thursday Daily Sun feature

By Michael Levin via the Cornell Daily Sun, 2/5/15

We all love Game of Thrones. There’s something quite romantic about the ice and rock of Westeros, a feeling unfortunately dispelled when you put on pants and step into the eight inches of snow sitting outside your window. You hear “Winter is coming,” and despair. But you know nothing, chilly readers—bear with me and we’ll see.

Dr. Todd Atwood loves big carnivores. He started his wildlife career with raccoons and coyotes and graduated to wolves for his PhD work. Four years ago he bumped up a weight class, leaving a job working with black bears in Arizona to study the biggest land carnivore in the world: the polar bear.

At the United States Geological Survey Polar Bear Research Program in Anchorage, Alaska, Dr. Atwood’s team focuses polar bear biology, ecology, and population dynamics. But as the effects of climate change become increasingly urgent, they’ve taken a particularly close look at arctic sea ice.

“Without sea ice you can’t have polar bears,” he said. The bears use it as a platform to forage for the seals that make up the bulk of their diet, since they aren’t agile enough to catch them in open water. Simply put, without sea ice, polar bears don’t eat.

Fortunately, bears have pretty flexible metabolisms. That’s what you’re seeing when brown and black bears hibernate- they’re slowing their metabolism down to the point where they can just nap winter away. Polar bears, however, laugh at winter and their wimpy, pigmented cousins. Their drops in metabolism are accompanied by virtually no change in daily routine. Dr. Atwood calls this a “standing fast;” the bears can survive without food anywhere between four and eight weeks. It’s not exactly healthy, but most will survive the ordeal.

Unfortunately, as greenhouse gas emissions increase and climate change takes hold, sea ice dynamics have changed. Since satellite monitoring began in 1979, scientists have tracked a 10-15% loss of sea ice every decade—a 40-45% total reduction since then.

To further complicate things, the ice is breaking up earlier in the spring and reforming later in the fall, leaving polar bears with longer fasts. “The concern,” Dr. Atwood said, “is when we see bears fasting for eight weeks we’re going to see declines in body condition, survival, and, ultimately, abundance.”

So how do you evaluate the health of a polar bear population in the first place? If you answered, “lean out the open door of a helicopter flying at 40 mph in -25 degree weather, and shoot a tranquilizer dart into nine feet and 1600 pounds of pure arctic fury,” you’d be crazy—and absolutely right.

Dr. Atwood does exactly that when setting out examine individual polar bears. With a small team of other scientists and a pilot, he’ll track a bear across using a helicopter and herd it to a featureless area with potentially hurtful terrain. Once the bear is in the clear, he’ll lean out of a hatch in the chopper, connected to his seat by a shooters harness, and pull the trigger when he has a clear shot.

“It sounds harder than it really is,” he said, with zero sarcasm.

Fifteen minutes later, the bear is out and his team moves in. They take various samples to assess the bear’s health, and are back in the chopper watching it wake up in under an hour. With enough samples from different bears in an area, they can determine the overall status of the population.

Now no one, least of all me, wants to see a great story like that spoiled with politics. But Dr. Atwood said something that this article would be much poorer without:

“The future isn’t written yet. The same science that portends doom and gloom with unmitigated greenhouse gas emissions also supports the potential for long-term polar bear persistence, if they can be mitigated. I worry that people have become too fatigued by the political debate over climate change, and don’t realize that there is still a chance for their survival. We just need to act.”

This man works in one of the most harsh and unforgiving biomes on the planet, with a species whose future is regarded with general melancholy. He shoots polar bears from a speeding helicopter, in temperatures well beyond freezing. And out of all that, it’s you he’s worried about. If your inaction can generate significant concern in a man like that, you must have some serious potential stored up for when you do decide to act.

Michael Levin is a senior in the College of Agriculture and Life Sciences from Scarsdale, NY, who loves being outside and telling stories—not necessarily at the same time. He’d love to hear from you at mlevin@cornellsun.com. The Wild Life appears on alternate Thursdays this semester.

Views expressed in News posts may not be those of Cornell University. No endorsement is implied.