2/4/2014 10:52:50 PM
Protecting Polar Bear Dens
After months of waiting, I once again find myself on Alaska's North Slope, taking part in a project that will potentially change the way we locate and protect denning female polar bears and their cubs—and despite the frigid temperatures, I couldn't be more excited to carry it out.
Unless you decide to join an oil crew, it's likely that you won't ever be making a trip to the North Slope. Outside of the small town of Barrow, the only real concentrations of people on the slope are in oil camps, and they make for an interesting place to spend a few weeks. At our most recent camp, I made the mistake of waking up my oil worker roommate as I barged into the room. He wasn't happy, and I got an earful. In fact, I probably would have felt more comfortable stumbling into a polar bear den! While camp life can present a unique set of challenges, we're thankful for the help that we get from the industry folks up here, and we're doing our best to help them avoid and conserve essential polar bear denning habitat.
On this short but productive trip to the Arctic, we tested new technology that may make it easier for us to find and study denning female polar bears. I often get asked why our team focuses on researching the denning habits of polar bears. I think a basic understanding of denning biology goes a long way to answer that question:
When female polar bears on the North Slope first dig their dens in November snowdrifts, they search for a location that will serve as a safe, secure place to raise their young. After digging in, the snow will gradually accumulate and cover the entrance to the den, sealing the female inside and obscuring the den from view. The female generally gives birth in December to her tiny, one-pound cubs (typically one or two cubs, with two being the most common).
At birth, polar bear cubs are smaller than you might think. The short gestation reduces the amount of pregnancy stress on the mom's body. Over the following weeks, she will nurse them until they are strong enough to leave the den in March or April. The amazing part of all of this is that the female has just spent months without feeding during the resource-limited fall months prior to denning, and then will continue to fast while she is inside the den. Some female polar bears will go eight or nine months in a fasting state! Female polar bears walk a razor's edge between having enough energy to give birth to their cubs and raise them and still survive, and the denning months represent a very delicate and important period of their lives.
Understanding how vulnerable these bears can be during the denning period probably gives you a better idea of why it is so important that we learn as much as we can about denning habits, and then protect females and cubs as best as we can. With human influence being felt more and more strongly in Arctic ecosystems, future polar bear generations are relying on humankind to preserve their way of life, and steps toward that goal need to be taken now. It's my hope that the research we are conducting in the Alaskan Arctic will give us the insights we need to better understand a beautiful and fragile component in polar bear biology.