Submitted by Anonymous on Wed, 11/07/2007 - 10:04
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SEDNA Beaufort Sea Ice

Can you tell me how polar bears fit into the ecosystem?

Fri, 11/09/2007 - 13:54

Robert Harris

Hi -- Greetings from Vermont!Polar Bears are the top preditors (hunters) above the Brooks Range in the Arctic.  Polar Bears will hunt and eat mainly ringed and bearded seals. But they will also eat small Walrus, Beluga whales, Caribou, and just about anything else that they run into.  Polar Bears will also scavenge and feed on dead animals they may find such as a Bowhead Whale carcass.
I am told that Polar Bears have a keen sense of smell and are very good seal hunters.  The Polar Bears will look for seals in openings in the ice called leads or find air holes that the seals are keeping open.  Some times the polar bear can surprise a seal that has hauled out on the ice to rest.  Polar Bears sneak up slowly on on the seals and are very careful. 
Since polar bears have a black nose, I have heard that sometimes they will put a paw over their nose as they sneak up on the seal to stay hidden; but this maybe a Tall Tale.
Polar Bears have hollow hair that allows sunlight to warm the air inside like in a greenhouse and this helps keep the bear warmer then it might be otherwise.
I have also heard that Polar Bears being the top hunter in their food web are curious about changes in their environment and will actually sneak up on people.
At the SEDNA ice camp we were 200 km northeast of Prudhoe Bay, far out on the sea ice.  Just as we were leaving two Polar Bears were sighted by the Dutch Science Plane that came to camp eating a seal 15 km from camp.  I was surprised because they were so far from shore.  It goes to show how well adapted to living on the sea ice that polar bears are.  When I left the SEDNA ice camp the bush pilot flew low and as we got close to the shore line we were able to see a lot of Polar Bear tracks.  So the Polar Bears seem to be more common closer to land.  Perhaps because fish are more common over the continental shelf and as a result there are more seals.
I hope this is helpful.
Sincerely,
Robert Harris
Hartford High School
White River Jct. VT