Tuesday, March 18, 2014

Polar Bears and Global Climate Change

The polar bear, (Ursus maritimus), prefers cold temperatures and has a native range that is largely within the Arctic circle.  The males tend to be much larger and usually weigh between 800 and 1500 pounds!  The females are normally about half of that size. The polar bear is carnivorous and feeds mostly on seals.  These bears spend most of their time near the sea, hunting on the ice.  They have large fat stores for energy use when there is no ice over the sea.  Polar bears are also good swimmers and have blubber as insulation for swimming in the frigid waters.  They are currently listed as vulnerable because of overhunting and population decline.

File:Polar Bear - Alaska.jpg

One of the other factors that could be causing polar bear populations to drop or causing polar bears to move to other climates is the fact that temperatures have been rising recently.  With temperatures on the rise, the polar bears will lose the ice that they need to use as a platform for hunting seals.  If the ice melts earlier, they must move to shore before they have built up enough of a fat store to last them throughout the summer and fall.  Researchers are looking at coping strategies that the bears have to adapt to this change in climate. There are also studies looking at how this climate change will effect the denning of females and many other factors about the bears population location.  Other researchers study how the break up of ice due to this climate change is causing population fluctuations.  I plan on talking about all of the ways that polar bears are being influenced by the climate change. Their behavior, population dynamics, coping strategies, and reproductive tendencies are just a few of the things I plan on talking about in my presentation.

Source 1  http://www.ecology.ethz.ch/education/Resilience_Stuff/Berkes_and_Jolly_2001.pdf

Source 2  http://icb.oxfordjournals.org/content/44/2/163.full.pdf+html

Source 3  http://web.a.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=c441afc0-4ce1-4e8b-9ecc-11bb26f61d4c%40sessionmgr4002&vid=2&hid=4114

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