The Polar Bear's Lifestyle
The polar bear is one that is unique to it's kind. It's scientific name (Ursus martimis) or "sea bear" implies that the bear is actually a marine mammal that spends much more time at sea than it does on land. They are one of the largest carnivores in the world today, only rivaled by the Kodiak brown bears in southern Alaska.
The polar bear's main habitat is sea ice. They have numerous adaptions that allow them to survive in such harsh climates. Their fur is thicker than any other bears' and covers their entire body, even their feet. A thick layer of blubber beneath the fur provides buoyancy and insulation. Their main source of food is the ringed seal, which provides the perfect amount of fatty meat for the bears. They are excellent swimmers and have been seen as far as 200 miles from land in the arctic oceans.
Global Warming's Effects: Loss of Sea Ice
No Fish, No Seals, No Polar Bears
The main threat the global warming poses to the bears is the loss of their main habitat: the sea ice. The larger gap of open water between the ice and the land allows for rougher wave conditions, and making the swim from the shore to the sea much more dangerous. The ice is also melting earlier in the year and returning later, causing the polar bears to have to wait longer to eat.
Shrinking the polar ice cap will also cause a decline in the seals that the bears prey on. The seals come up into the breathing holes that are formed on the ice, and that is where the polar bears are able to snatch them up. Without ice, the bears can't get seals. The seals are also growing more scarce because the fish that the seals eat like these ice cap areas, and they're not going there anymore either. No fish, no seals, no polar bears. It's a harsh cycle.
Witnessed & Expected
The polar bear was initially listed as a threatened species under the Endangered Species Act because of the decline in it's habitat. Today, they are seen as vulnerable on an international level because there are only 20,000-25,000 polar bears in the entire world. The U.S. Geological Survey projects that 2/3 of the remaining population will disappear by the year 2050.
Wake-Up Calls
- In 2004, biologists discovered four drowned polar bears in the Beaufort Sea, and suspected the actual number was much higher. It was the first time ever that they attributed the cause of death to a combination of retreating ice and rough water conditions.
- In 2011 Arctic sea ice extent for January was the lowest ever in satellite record for that month.
- The year saw the second lowest Arctic ice levels ever.
- A female polar bear reportedly swam nonstop for nine days across the Beaufort Sea before she found ice. She lost 22% of her body weight and her cub in the process.
- Polar bears are going hungrier for longer periods of time, resulting in cannibalism amongst themselves. They have been known to kill for dominance, but biologists had never witnessed them doing it purely out of need to survive the starvation.
