On Thin Ice
by Brian Payton
February 11, 2006

ONE AUTUMN NIGHT, I fell asleep near a pair of hungry polar bears. I was out on the tundra in a mobile lodge on the shore of Hudson Bay, spending some time with the world's largest land predators. My bunk had a small window by it with a view onto a patch of snow illuminated by a large spotlight. After an unforgettable afternoon photographing bears at rest and play, I stretched out in my sleeping bag as they took turns sitting up on their haunches, peering back at me.

The largest member of the bear family, adult male polar bears (Ursus maritimus) weigh between 770 and 1,500 pounds. The skin of a large male specimen could cover a small car. Incredibly, most polar bears are born weighing just over a pound.

They are the newest bear species, evolutionarily speaking. Polar bears are thought to have evolved into a distinct species between 100,000 and 200,000 years ago. Previously, seals were able to haul themselves onto the ice pack and nurse their young in peace — until a brown bear (Ursus arctos) noticed and decided to investigate. The descendants of that bear came to depend on seals and developed into the white bears we know today.

Polar bears spend the winter and spring on the ice and are forced ashore in summer to await its return. Because there isn't much for them to do in summer, they spend a lot of time wrestling and watching the tourists and scientists who have come to watch them.

These days, however, it's becoming increasingly difficult to look them in the eye.

Life at the top of the Arctic food chain means polar bears' bodies concentrate many of the chemicals that waft up from our activities in the industrial south. For years, scientists have been tracking increasing levels of toxins (including DDT and PCBs) in polar bear flesh, organs and milk. And now, with polluted bodies, they are faced with an even bigger threat.

Polar bears rely on ice that forms fresh each year adjacent to land. They hunt seals at the ice's edge, at breathing holes in the ice and in snow-covered hollows on top of the ice where seals hide their pups. For polar bears, it's all about ice. Unfortunately, the ice is disappearing.

Arctic temperatures are rising twice as fast as the rest of the globe — and there has already been a dramatic reduction in the Arctic Ocean's summer ice pack, which is 20% smaller than it was in the 1970s. Scientists expect it will continue its precipitous decline, resulting in dramatic effects throughout the Arctic ecosystem. In their 2004 "Arctic climate impact assessment," the world's foremost climate and Arctic scientists predicted that, by the end of this century, the changes in the north because of global warming may be so profound that the entire species (estimated at 22,000 to 27,000 polar bears) could vanish — along with the environment that shaped them.

Watching those bears outside my window, I couldn't help but wonder: How will their end come? Will a few stragglers lie down on the shore of Hudson Bay, waiting for the ice that never forms? Or will they head for the nearby town of Churchill, in Manitoba province, and make their last stand at the dump? In Inuit legends, polar bears are actually people when inside their dens and transform into bears only when they don their hides to go out into the cold. Perhaps polar bears will have to leave their fur coats at home.

Or will we take the necessary steps to save them and their environment? Will urbanites forgo their SUVs in favor of public transit? Will voters stop electing politicians who are contemptuous of science and international cooperation? Even as we contemplate these questions, our window of opportunity to save the polar bear is closing.

As I returned their gaze that cold, autumn night, I wanted to believe that awareness fosters change. Then the generator shut down, and I watched my companions fade to black.

BRIAN PAYTON is author of the forthcoming "Shadow of the Bear: Travels in Vanishing Wilderness."
from: the Los Angeles Times http://www.latimes.com/news/printedition/california/la-oe-payton11feb11,0,1728432.story?coll=la-headlines-pe-california