Species interactions |
-Seals |
Interactions
Polar bears are solitary animals. They live a life with minimal interaction with their own species other than when they mate or when the females raise their children. Polar bears are at the top of the food chain and are therefore are the predators of the north. Even humans have difficulty hunting the massive animals(Year, n.d.). Polar bears interact with little other animals, other than to prey upon them. The main and most popular interaction the polar bear experiences is that with seals. Polar bears also interact with the famous killer whales. A third species killer whales interact with are walruses.
Seals
Ringed seals create hoes in ice to use as breathing holes. Since most of the animals that hunt seals are mammals, most of them need oxygen and therefore cannot go under this sea ice, because they might suffocate. This allows for the seals to be safe as long as they stay near their breathing holes and under the ice. Polar bears will find these holes and wait for the seals to come. This is when they will kill and eat the seal ("Hunting and Diet," 2014).
Figure 1: Pink- seal population Blue-polar bear population
killer whales
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Since seals are the primary source of food for polar bears, they are an important factor in population growth and size. Predation follows a sinusoidal and cosine graphs. One population grows while the other falls. It is a cycle that carries on each year. If there are lots of polar bears more seals will be eaten, the next year there will not be enough seals for polar bears to survive(Brookes, 2013, p. [Page 525]). The loss of polar bears will then cause for more seals to survive and the cycle continues as seen in figure 1. This relationship is not as impactful as a whole due to the amount of seals in comparison to the amount of bears, but in smaller regions the shifts in population can be seen.
Walruses
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Refrences
Brookes, L. (Ed.). (2013). Biology 12.
Hunting and diet. (2014). Retrieved November 23, 2014, from Polar Bears International website: http://www.polarbearsinternational.org/about-polar-bears/essentials/hunting-and-eating
Polar bear diet. (n.d.). Retrieved November 23, 2014, from World Wildlife Foundation website: http://wwf.panda.org/what_we_do/where_we_work/arctic/wildlife/polar_bear/diet/
Smith, T., Dr. (n.d.). Killer Whales "Gang Up" to Capture Seal. National Geographic. Retrieved from http://video.nationalgeographic.com/video/orca-juvenile-training-lex
Wildlife Arkive. (2011, January 24). Retrieved from http://www.arkive.org/walrus/odobenus-rosmarus/video-11.html
IUCN Red List (June, 2009) http://www.iucnredlist.org/, Kastelein, R. (2008) Walrus. In: Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (Eds) Encyclopedia of Marine Mammals. Academic Press, London.,CITES (June, 2009) http://www.cites.org/, Jefferson, T.A., Leatherwood, S. and Webber, M.A. (1993) FAO Species Identification Guide. Marine Mammals of the World. Food and Agriculture Organization of the United Nations, Rome., Burnie, D. (2001) Animal. Dorling Kindersley, London., Kastelein, R.A. (January, 2011) Pers. comm., Macdonald, D.W. (2006) The Encyclopedia of Mammals. Oxford University Press, Oxford, Nowak, R.M. (1999) Walker's Mammals of the World. Johns Hopkins University Press, Baltimore,Center for Biological Diversity (October, 2009) http://www.biologicaldiversity.org/news/press_releases/2009/pacific-walrus-09-08-2009.html, Taylor, M.F.J., Suckling, K.F. and Rachlinski, J.J. (2005) The effectiveness of the endangered species act: a quantitative analysis. Bioscience, 55(4): 360-367, Clark, J.A., Hoekstra, J.M., Boersma, P.D. and Kareiva, P. (2002) Improving U.S. Endangered Species Act recovery plans: key findings and recommendations of the SCB Recovery Plan Project. Conservation Biology, 16: 1510-1519.
Year, J. (n.d.). Polar Bear. National Geographic. Retrieved from http://animals.nationalgeographic.com/animals/mammals/polar-bear/
Brookes, L. (Ed.). (2013). Biology 12.
Hunting and diet. (2014). Retrieved November 23, 2014, from Polar Bears International website: http://www.polarbearsinternational.org/about-polar-bears/essentials/hunting-and-eating
Polar bear diet. (n.d.). Retrieved November 23, 2014, from World Wildlife Foundation website: http://wwf.panda.org/what_we_do/where_we_work/arctic/wildlife/polar_bear/diet/
Smith, T., Dr. (n.d.). Killer Whales "Gang Up" to Capture Seal. National Geographic. Retrieved from http://video.nationalgeographic.com/video/orca-juvenile-training-lex
Wildlife Arkive. (2011, January 24). Retrieved from http://www.arkive.org/walrus/odobenus-rosmarus/video-11.html
IUCN Red List (June, 2009) http://www.iucnredlist.org/, Kastelein, R. (2008) Walrus. In: Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (Eds) Encyclopedia of Marine Mammals. Academic Press, London.,CITES (June, 2009) http://www.cites.org/, Jefferson, T.A., Leatherwood, S. and Webber, M.A. (1993) FAO Species Identification Guide. Marine Mammals of the World. Food and Agriculture Organization of the United Nations, Rome., Burnie, D. (2001) Animal. Dorling Kindersley, London., Kastelein, R.A. (January, 2011) Pers. comm., Macdonald, D.W. (2006) The Encyclopedia of Mammals. Oxford University Press, Oxford, Nowak, R.M. (1999) Walker's Mammals of the World. Johns Hopkins University Press, Baltimore,Center for Biological Diversity (October, 2009) http://www.biologicaldiversity.org/news/press_releases/2009/pacific-walrus-09-08-2009.html, Taylor, M.F.J., Suckling, K.F. and Rachlinski, J.J. (2005) The effectiveness of the endangered species act: a quantitative analysis. Bioscience, 55(4): 360-367, Clark, J.A., Hoekstra, J.M., Boersma, P.D. and Kareiva, P. (2002) Improving U.S. Endangered Species Act recovery plans: key findings and recommendations of the SCB Recovery Plan Project. Conservation Biology, 16: 1510-1519.
Year, J. (n.d.). Polar Bear. National Geographic. Retrieved from http://animals.nationalgeographic.com/animals/mammals/polar-bear/