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Interactions

 

                

General Interactions:

image of clip artCommunication among polar bear populations seems to source from the female polar bear and her young.  In fact, the female polar bear and her young are considered to be the only social unit among the polar bear population (Geist, 304).   After pregnancy, the mother devotes much of her time to her new born cub.  During the few months after birth, the mother and cub remain under close quarter in the den, where they are able to interact with one another.  Contrastingly, male polar bears are quite solitary and spend the majority of their time hunting and looking for prospective females for reproduction. 

 

Competition:    

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    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.

located at http://www.polarbearsinternational.org/bear-facts/

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. 

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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. 

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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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Created by: Alison Kolinski
 Feel free to contact me with comments at kolinski.alis@students.uwlax.edu