Competition:
During breeding season, male polar bears compete
with other males when looking for potential mates. Some males travel long
distances in order to find optimal mating conditions.
Predation:
Polar bears stand at the top of
the food chain. There, they are able to retain their position as
primary predators. Polar bears primarily prey upon ringed seals
and intermittently feed on bearded seals and other small marine mammals.
The picture at the bottom left was taken
from
Polar Bears
International. The
bear's sharp teeth aid in chewing during
meal time.
Polar bears that have reached maturity, generally
consume only the fatty portions of their meal. This is
characteristic is important for regulating body
temperatures. However, the remaining meat does not go to
waste; in fact, young cubs act as scavengers and finish what is
left over. Nutritional habits such a these are important to cub
survival. When cubs are young, they are not as efficient in
capturing their own prey. Thus, if left over food was not readily
available to young cubs, they would likely starve.
Luckily, polar bears do not have to worry much
about predation. Because polar bears are nearly the largest bear
in the family ursidae,
and remain as one of the largest mammalian animals, very few, if any
organisms prey upon the polar bear. However, if predation
does occur, predators are of equal or greater complexity.
Predators of Ursus Maritimus are usually members of the
family ursidae or human beings. |
Environmental
Interactions:
Over the past few years, global warming has become
a major environmental concern. The effects of global warming are much more
complex than simply minor environmental harm; global warming not only interrupts
the normal lifestyle of different organisms, but also drastically alters the
ecological niche at which these organisms reside. In fact, increasing
temperatures, due to global warming, have had an immense impact on the
homes of many northern polar bear populations. Research has been done to
show the relationship between global warming and polar bear populations.
Trends have shown a consistent decline in total ice cover. Over the past
25 years, total ice cover has declined by nearly 14 percent. Researchers
propose that by year 2050, the sea ice favorable of most polar bears will
be located some several hundred kilometers north of the continental coastlines
(Derocher and Stirling, 22). If such trends continue, sea ice will quickly
diminish, morality rates will increase and reproductive productivity will
decrease.
As the climate continues to get warmer,
the sea ice will likewise begin to disassociate and disappear.
Eventually, the lack of ice cover will create major problems for organisms, such
as the polar bear. The polar bear's preferred ecological niche is near the
northern regions of highly concentrated sea ice. For hunting purposes,
polar bears rely on areas with abundant ice. Without annual ice, polar
bears will lose their ability to feed and hunt and will eventually be forced on
the mainland. As you can see, a domino affect is slowly beginning to
occur. As the climate warms, holes in the sea ice where seals breath and
polar bears typically feed will begin to disappear. As more and more polar
bears move onto land, competition for food will begin to increase. In
addition, the likelihood of finding food along the coastline will probably
be low as well. Thus, low food intake will likewise result in inadequate
adipose stores. Furthermore, lower fat consumption and food intake will
result in reduced energy. Since polar bears are very large, the energy
required to carry out daily activity is large as well. A decline in energy
and overall body mass will eventually effect the polar bears reproductive
productivity and may even result in death.
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