A landlocked polar bear, too close for comfort, forced a crew of five Wildlife Conservation Society (WCS) scientists to evacuate a remote camp in northern Alaska. The scientists were studying the impacts of climate change on Arctic shorelines.

Typically at this time of year, polar bears spend their days hunting seals on sea ice, but recent warming has caused the ice to recede miles from shore. In fact, the bears have been trapped on land in Arctic Alaska all spring and summer, unable to swim out to sea ice. Their condition is unknown.

“It is ironic that our efforts to understand how climate change is affecting wildlife were disrupted by the top Arctic predator displaced by climate,” said Dr. Steve Zack of WCS. He and conservation scientist Joe Liebezeit, who together lead the Arctic studies for WCS, will continue their work on shorebirds in the Prudhoe Bay region this season.

Although the crew had bear safety training, they were uncertain of how dangerous this or other polar bears in the region might be. Before a major storm could hit and make their rescue unlikely for days, WCS decided to charter a bush pilot to get the crew out.

“We saw the polar bear on our first clear day after several days of poor weather. The bear didn’t come near us, but the prospect of maintaining a round-the-clock vigil while trying to do our surveys had us concerned,” said Liebezeit. The field camp has food supplies for several weeks.

The crew was conducting surveys of shorebirds feeding on the shorelines prior to their southward migrations. The shorelines north of Teshekpuk Lake on the Beaufort Sea have experienced dramatic erosion because of the warming climate.

The study was an attempt to understand how such erosion was affecting the ability of millions of shorebirds to refuel with food energy before their southward migrations to Asia, South America, and other distant lands.

In May, the polar bear was listed as Threatened under the Endangered Species Act. The Teshekpuk region also recently garnered some protection from expanding oil development by the Department of Interior because of its importance to wildlife. WCS and other groups advocated such protection. WCS has been studying Arctic wildlife in Alaska since 2001.

（引自www.chinabiodiversity.com    2008年8月13日）