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Essay On Polar Bears

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* Perhaps the most noticeable and striking characteristics of a polar bear is its color. The fur shafts themselves are not white. The shafts actually lack pigmentation and are transparent which allows them to scatter and reflect light resulting in ideal camouflage in a world of ice and snow.

* Polar bears paws are also well adapted for the environment in which they live. They can measure up to 304 mm. (12 inches) in width. These large paws allow polar bears to better distribute their weight more evenly across ice surfaces.

* Polar bears do not hibernate. Females will, however, dig dens in the snow and give birth to their cubs in the winter. The den provides insulation and protection until the sow and her cubs emerge.

* The scientific name for polar bear is Ursus maritimus which means sea bear in Latin. They were first identified by Constantine J. Phipps in 1774. Different sources express different theories on the origins of polar bears. Fossil evidence lead researchers to believe that polar bears may have split off from a population of brown bears that became isolated during the Pleistocene epoch. More recent DNA evidence suggests that polar bears became distinct species from brown bears 4-5 million years ago. It has been documented that polar and grizzly bears have produced fertile hybrid offspring. Other names for the polar bear include the Inuit word "nanook", and the Norwegian name of Isbjorn which means "ice bear."

* Polar bears are members of the bear family Ursidae. They are a carnivorous bear which can be found throughout the Arctic region where they rely on sea ice to sustain their hunting activities. Canada hosts approximately 60% of the polar bear population. Other areas inhabited by polar bears include Alas...

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...t of Biological Sciences with the University of Alberta. He has studied polar bears in the Canadian Arctic for over 40 years. His studies have linked the loss of sea ice due to climate change to the decline of the polar bear population.

* Other readings of interest about polar bears:
- Susan McGrath, July - 2011, National Geographic, "On Thin Ice" http://ngm.nationalgeographic.com/2011/07/polar-bears/mcgrath-text?rptregcta=reg_free_np&rptregcampa...

- Ian Stirling, 2011, "Polar Bears, The Natural History of a Threatened Species"

- Pagano, A. M., G. M. Durner, S. C. Amstrup, K. S. Simac, and G. S. York. 2012. Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water: Canadian Journal of Zoology 90:663-676. doi: 10.1139/z2012-033http://www.nrcresearchpress.com/doi/abs/10.1139/z2012-033#.UxOE1ZWPLoo
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