December 27, 2002 - Biodiversity

sagar: Author=’Deborah Byrd’ program=’3644′ video=”Polar bear cubs with their sedated mother. Photo by Captain Budd Christman, NOAA Corp.DB: This is Earth and Sky. A listener wants to know, “. . . how come we don’t have penguins in the north pole and polar bears in the south pole? Could they be transplanted?”

JB: Most of the Arctic is sea ice, connected to surrounding land masses. Brown bears from northern hemisphere forests probably walked into the frozen realm of the Arctic. Over the aeons, they adapted to their surroundings – to become polar bears.

DB: Meanwhile, Antarctica is a land mass, surrounded by an ocean. It’s thought that ancestors of today’s penguins could fly. They might have flown to Antarctica.

JB: So could you transplant polar bears to the Antarctic – or penguins to the Arctic? Antarctic penguins have very special requirements for feeding and breeding. And in Antarctica, partly because are no bears, you can walk right up to a penguin – all their natural predators come from the sea. For that reason, penguins transplanted to the Arctic would be very vulnerable.

DB: At the same time, there might be some denning problems for female polar bears transported to Antarctica. But these bears might do extremely well feeding on Antarctic penguins and seals that have never known a predator on land. Special thanks to the “U.S. Forest Service”:http://www.fs.fed.us/ and to the “National Fish and Wildlife Foundation”:http://www.nfwf.org/ – supporting the conservation of native fish, wildlife, plants, and their habitats. I’m Deborah Byrd, with Joel Block, for Earth and Sky.

Written by earthsky