Get ready for International Polar Bear Day. The N Y Times reported last December 20th that the conservation organization Polar Bears International, has so designated this February 27.
The debate over whether polar bears are an endangered species continues since it was made into a major environmental issue in the United States by Al Gore's 2006 film An Inconvenient Truth. With so many real and serious environmental problems to deal with, many ignored, it is time to set the record straight about polar bears.
Globally, more than one third of the nineteen subpopulations of polar bears are increasing or stable, while the remaining third have insufficient data available; its status in the central Arctic Basin, the largest of the nineteen designated regions, is completely unknown.
The offshore sea ice that lies well north of the pack ice edge has not been surveyed in any comprehensive fashion for polar bears OR ringed seals, their primary prey: we simply do not know how many bears or seals live deep in the polar pack, although several studies suggest that the number of ringed seals living and breeding well offshore must be substantial
Virtually the only areas studied in any detail, for polar bears and ringed seals, are the nearshore areas of Hudson Bay (Canada), the Beaufort Sea (shared by the USA and Canada) and Svalbald (Norway).
Some studies have also been done in Canada’s Davis Strait/Baffin Bay and the Canadian High Arctic.
There is only about thirty years worth of data for even the most intensely studied populations.
Most of what we know about polar bear biology is based on the western Hudson Bay population but since this is an anomalous population, Hudson Bay bears are not a good proxy for ALL polar bears.
Among polar bear females, pelagic-dwelling bears live in drifting sea ice year round, while nearshore dwelling females inhabit shorefast ice year round. Both pelagic-dwelling and near shore dwelling individuals of both sexes are known in all subpopulations studied and each type behaves differently to reduced seasonal ice.
SHOULD POLAR BEARS BE LISTED AS A LEGALLY ENDANGERED SPECIES?
Polar bears evolved from brown (grizzly) bears some time between 200,000 and 100,000 years before present, so polar bears or their near-term ancestors survived the previous greatest warming approximately 100,000 years before the present.
“By 100,000 years ago they had evolved into something like the polar bear of today. Although polar and brown bears now look and act rather differently, their genetic closeness is demonstrated by matings in zoos that produce fertile offspring.”
Polar bears evolved from brown (grizzly) bears some time between 200,000 and 100,000 years before present, so polar bears or their near-term ancestors survived the previous greatest warming approximately 100,000 years before the present.
“By 100,000 years ago they had evolved into something like the polar bear of today. Although polar and brown bears now look and act rather differently, their genetic closeness is demonstrated by matings in zoos that produce fertile offspring.”
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