Polar Bears- Michael Chourappa Bio 112

POLAR BEAR 

(Ursus maritimus)

          Quick Facts                        

Lifespan:	20-25 years
Weight:	Males: 550 - 1,320 lbs, Females 200-700 lbs
Height:	Males 8 - 9 feet Females 6 - 7 feet
Population:	20,000-25,000 polar bears
Mating Season:	Late March-May
Gestation:	About 8 months
Litter size:	1 - 4 cubs, 1 or 2 common

                                                       

Ecology

Polar bears are marine mammals that can be found in the thin ice sheets of the Arctic Circle. These bears have adapted to the marine life of the Arctic by having a thick coat of insulated white fur along with their slightly webbed strong front paws that provide them buoyancy and warmth in the cold icy waters. Don't be fooled by their thick white fur because polar bears actually have black skin to absorb the warming sun rays that hit the Arctic. This white fur provides padding for their paws and also covers a layer of fat known as blubber that protects them from cold surfaces and ice. 

Habitat

These mammals are only found in the Arctic. They spend most of their time on the edges of ice where the currents and ice patches meet (best chances to find prey such as seals). Females usually build dens deep in the snow drifts when they give birth to cubs. Polar bears travel thousands of miles per year in order to find food. There are approximately 19 subpopulations of Polar bears in the Arctic region.      

Diet
Polar bears eat ringed seals and bearded seals. However they can also munch on walruses, carcasses of whales and even birds' eggs. They are known to travel great distances in search of food.

Behavior
These white giants are dependent on the stable ice patches where they usually hunt, find mates and building shelter. These animals are strong swimmers and usually float due to their buoyant body shapes in the Arctic. They are also solitary when they reach adulthood and only interact with other polar bears to mate and raise cubs. Bear cubs only stay with their mothers for a couple years. Mother polar bears produce about 5 litters in their lifetime. Also, Polars do not hibernate in the winter unlike other bears.

Population Decline and Listing

Polar Bears are a vulnerable species and are unfortunately facing endangerment due to sea ice losses due to climate change being one of the leading threats to their existence. In 2014, the IUCN Polar Bear Specialist Group conducted research only to find that out of the 19 subpopulations of Polar Bears, 3 are declining, 1 is increasing, 9 have insufficient data and only 6 are stable.

Declining                   

• Baffin Bay
• Kane Basin
• S.Beaufort Sea

Stable

• Davis Strait
• Foxe Basin
• Gulf of Boothia
• N. Beaufort Sea
• S. Hudson Bay
• W.Hudson Bay

Increasing

• M'Clintock Channel

Data deficient

• Arctic Basin
• Barents Sea
• Chukchi Sea
• East Greenland
• Kara Sea
• Lancaster Sound
• Laptev Sea
• Norwegian Bay
• Viscount Melville Sound

Polar Bears were listed under the Endangered Species Act by the U.S. Fish and Wildlife Service on May 15, 2008. It also qualified as a "depleted species" under the Marine Mammal Protection Act of 1972. 

Threats

The leading threat to polar bears today is the loss of habitat caused due to climate change and greenhouse gas emission. However in  the 1960s and 70s, polar bears faced the threat of unregulated commercial and sport hunting. This was taken care of by the 1973 Agreement on the Conservation of Polar Bears signed by the U.S, Canada, Russia Denmark and Norway. The bears are also going through a loss of prey due to the climactic change of the Arctic waters. Other threats to this species include pollution, disease and sometimes the lack of potential mates. 

Management Plans

• Support International conservation efforts
• Manage human-bear conflicts
• Manage Subsistence harvest
• Protect habitats and shelters (dens)
• Minimize risks of pollution and contamination
• Conduct strategic monitoring and further research

7 summarized steps of Recovery

1. Develop and implement an effective communication strategy to inform U.S. and other leading nations the need to reduce greenhouse gas emissions and other anthropogenic causes of Arctic Warming
2. Continue the USFWS plan to be carbon neutral by 2020 and engage in climate change mitigation
3. Work closely with Range States to implement conservation actions outlined in the Circumpolar Action Plan for polar bears
4. Develop and implement human-polar bear interaction and safety plans for the U.S. 
5. Continue den detection, habitat work and mapping in the United States
6. Model population-level effects from infection levels
7. Update existing oil spill models that overlap with seasonal polar bear movements

Personal Actions

• I will try my best to promote the recovery of such a majestic species on social media and other networks
• I will also keep in mind my personal ecological footprint and spread the word of reducing our anthropogenic effects in the Arctic waters. 

Sources:

Recovery Plan

http://ecos.fws.gov/docs/recovery_plan/Polar%20Bear%20Conservation%20Mgmt%20Plan.pdf

Geography 

http://animals.nationalgeographic.com/animals/mammals/polar-bear/

Behavior, Population and Threats

http://www.polarbearsinternational.org/about-polar-bears/status-and-threats

Basic Facts

http://www.defenders.org/polar-bear/basic-facts

Images

http://www.polarbearsinternational.org/sites/default/files/legacy/Polar_Frontier_18th-08-10_127.jpg

http://d1by67ljd45m4v.cloudfront.net/media/9A5E7548-BD90-82C2-FA9EB8900FD274B3.jpg

Map

http://www.polarbearsinternational.org/media/images/polar-bear-subpopulation-map