National Geographic: An estimated ten thousand Pacific walruses have huddled together on a remote island in the Chukchi Sea (map), an unusual phenomenon that's due to a lack of sea ice, experts say. The giant marine mammal is known to "haul out"literally haul its body onto ice or land to rest or warm upon various places along Alaska's coast. But with the Arctic warming up and melting much of its floating ice, there are limited areas for the walruses to gather. This forces them to cluster on land in huge aggregations...