© Dr. Andrew Derocher
6/27/2013 6:58:13 PM
The Bounty of the Polar Desert
Recently, I had the opportunity to join my supervisor, Dr. Andrew Derocher, for a spring field season tracking polar bears in Viscount-Melville Sound. One week after returning, I had lunch with Dr. Nick Lunn, Alysa McCall, and Dr. Ian Stirling. “So what did you learn on your trip north?” Ian casually asked me. My mind momentarily hesitated at the question, and I ended up voicing the first thought that came to me: “Well, the area certainly wasn’t as productive as I had expected.”
Indeed, we had only sighted nine polar bears over the seven days of flying in Viscount-Melville Sound. To put that into perspective, on our flight home over the sea ice of the southern Beaufort Sea, we spotted six polar bears in one hour. From appearances, the sea ice in Viscount-Melville Sound seemed not nearly as productive as the sea ice of the Beaufort.
But as I continued to reflect on the trip, I realized that the answer I gave at lunch was only partially correct.
In retrospect, the most profound aspect of what I witnessed during the field season was the variety of life thriving in the adverse environmental conditions of the Arctic: ringed seals, bearded seals, arctic foxes, arctic wolves, muskoxen, Peary caribou, ptarmigan, grizzly bears, and of course polar bears—all of which are year-round residents. Now, anyone with access to a good book on animals could tell you they live there (maybe with exception of the grizzly), but it is something else to see these animals in person. The landscape is a starkly beautiful yet uninviting frozen tomb, dotted by groups of muskoxen and Peary caribou gathered near wind-swept ridges. The image is as strange as spotting a few gemsbok on a hot sandy ridge of the Kalahari. One can’t help but think “How does an animal like that make a living in a place like this?”
In fact, about the only difference between the hot sandy deserts of the world and the High Arctic is the temperature. Fresh water comes at a premium in either region. Melting water from snow is easy enough with a propane stove, but much more costly using body heat, which is why arctic animals have invented other strategies for obtaining water. Both polar bears and seals can obtain the water they need from the high-fat food they digest, as water is a byproduct of burning fat. Impressively, muskoxen can conserve water equivalent to that of a camel.
Additionally, both regions exhibit wide fluctuations in productivity and residents must be flexible enough to take advantage of short windows of opportunity. As we saw, arctic foxes capitalize on good seasons by doubling their output of offspring. Polar bears can eat a meal equal to 20% of their body mass in a single sitting, maximizing the energy gained from finally catching their elusive prey.
In a sense, this field trip reminded me that polar bears are a single part of a magnificent and dynamic ecological system, likely one of Earth’s last true wildernesses. It also solidified in my mind that by acting to conserve the polar bear, we inherently protect far more.