Polar Bears In Danger

Kathryn's Visual Essay 2016

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A Beautiful Creature in the North --the Polar Bear

Being at the top of food chains in the arctic area, polar bears are feared by most people as they are the most powerful predators in the north.

At the same time, they are loved by many. Polar bears display a high level of intelligence. They are curious, playful, and sensitive to the environment around them.

Polar bears smash the spy cams - Polar Bear: Spy On The Ice - BBC One

--Where do they live?--

Arctic Ring of Life

Polar bears usually lives in areas where their food source--seals--is the most abundant. Rarely do they go up north to the colder area (marked by dull red colour) where it is hard for them to hunt.
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--Survivor in the North--

Polar bears has developed many adaptations in order to survive in the harsh weather of the Arctic area.

Adaptations/ Defense Mechanisms:


--Characteristics of Polar Bear Population--

A little history...

Polar bears and brown bears are relatively closely related, as polar bear is found to have evolved from brown bears less than 500,000 years ago.
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Population Size & Density

According to the most recent data, the total number of polar bears is approximately 26,000.

In areas close to land, where the population of polar bear is monitored, data shows a quite stable population. However, declines in population density has been spotted in recent years as the arctic ice shrinks.

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Distribution Pattern:

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The picture above shows the paths of 15 polar bears according to polar bear trackers. Because of the spaciousness in the Arctic area, polar bears rarely encounter each other, and they don't mark a specific area as their own.

Polar bears are neither territorial nor pack animals. They tend to scatter around individually and randomly as they travel thousands of miles during the year.
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In mating seasons, which is the late spring and early summer, the distribution pattern changes as male polar bear seeks out female ones by tracing their scent.


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Twins are the most common for a polar bear mother, but they can have singlets and triplets depending on body condition of the mom.
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Female polar bears tend to start mating around the age of 5 to 6, and average life expectancy is approximately 15 to 18 years old. On average, they give birth to 2 cubs every 2 years. Therefore, the fecundity of a female polar bear is 10 to 12 cubs.

Survivorship Curve:

Similar to many other mammals, polar bears have a Type I survivorship curve.

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Polar bear mothers usually spend 2 years raising the baby bears, ensuring their well-being as cubs and teaches them skills they need to survive independently.

The mortality rate significantly increases as polar bears approach the age of 15 to 18 years.

--Factors that Regulates Natural Population--

Symbiotic Relationships:

Commensalism relationship with Arctic Fox

Arctic foxes travels behind the polar bears and scavenge on scrap of food. The polar bear is hardly affected, and arctic fox benefits from this relationship.

Intraspecific Competition & Interspecific Competition:

Density-independent Factor that Causes Population Decline:

The 3 major causes of population decline are all density-independent.
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-- Analyzing the issue --

1. Loss of Arctic Sea Ice due to Global Warming

Though the process of global warming is unavoidable, human contributions are making the process to become much faster.
HD: Arctic Melt Time Lapse - Nature's Great Events: The Great Melt - BBC One
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Sea ice coverage is declining at the rate of 13% per decade. If the trend continues, then polar bears would suffer a loss of habitat, and consequently food.

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2. Industrial Impacts

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Offshore petroleum installations and operations in the Arctic are expected to increase in number. This expansion would likely affect polar bears and their habitat in many ways, including the following:

· Contact with spilled oil would be fatal.

· An oil spill would affect the entire food chain.

· Noise generated from onshore and offshore oil operations would cause disturbance.

3. Unsustainable Hunting

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Though regulations on harvesting polar bears has been effective in countries such as Canada. Many unreported killings of polar bears still exists in some arctic countries.


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WWF: Addressing Climate Change

WWF is working with some local organizations and is promoting the devastating impact of rapid climate change.

Polar Bear International: Monitoring Populations

Working with professors from University of Alberta, they have created a polar bear tracker to further analyze polar bears' behavior.
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Will polar bears become extinct? (n.d.). Retrieved January 22, 2016, from http://www.bbc.com/earth/story/20141107-will-polar-bears-become-extinct

Polar Bear Facts. (n.d.). Retrieved January 22, 2016, from http://www.bear.org/website/bear-pages/polar-bear/22-/70-polar-bear-facts.html

Polar Bear - National Wildlife Federation. (n.d.). Retrieved January 22, 2016, from https://www.nwf.org/Wildlife/Wildlife-Library/Mammals/Polar-Bear.aspx

Our Work. (n.d.). Retrieved January 22, 2016, from http://www.polarbearsinternational.org/our-work

Goodbye Toronto, Hello Winnipeg! (n.d.). Retrieved January 22, 2016, from http://www.torontozoo.com/PolarBearCub/Humphrey/

Polar Bear Facts | Animal Fact Guide. (n.d.). Retrieved January 22, 2016, from http://www.animalfactguide.com/animal-facts/polar-bear/