Toronto's last polar bear heads back up north

Bye, to Bisitek

As of Aug 21, 2007 Polar Bears are off display until further notice due to commencement of Tundra construction project.

Bisitek, 27, just moved to the Cochrane Polar Bear Habitat and Heritage Village to join the three other polar bears Aurora, Nakita and Nanook. Nicknamed “Bisi,” she is planning on retiring in Cochrane after spending most of her life at the Toronto Zoo.





Toronto Star, Sep 07, 2007

Polar bear lovers are out in the cold in Toronto. The last polar bear has left the Toronto Zoo and the exhibit has shut down while a $12 million, two-year redevelopment begins.

The zoo has shipped off 27-year-old Bisitek to northern Ontario, where she is to enjoy "a restful retirement" at the Cochrane Polar Bear Habitat, according to zoo officials.

The move was made to allow the zoo to launch a bigger and better polar bear habitat and tundra phase, where Arctic wolves, reindeer, snowy owls and other animals would be introduced.

The project is expected to be completed in 2009."Polar bear lovers will just have to be patient," said Toronto Zoo curator Maria Franke.

For the next two years, Cochrane will be the only Ontario city with polar bears in captivity.

The Cochrane exhibit now has four polar bears at the all-season habitat, located eight hours north of Toronto.

Bisitek, who was taken by a refrigerated trailer late at night last month, had been a fixture at the Toronto Zoo since 1980.

Orphaned in the wild, she was donated to the zoo by the Canadian Wildlife Service.

Last fall, Bisitek's pen mate Kunik died and the cause of his death has been attributed to West Nile virus.

Kunik began having trouble using his hind legs Sept. 19 and was put down for humane reasons two days later.

"We will miss Bisitek very much," Franke, the Toronto curator, said. "The polar bears were one of the top animal attractions at the zoo. However, it's going to be an exciting time introducing new polar bears to the Toronto Zoo."

Zoo officials say that Bisitek was sound asleep when she reached her destination and was not disoriented upon arrival.

She was accompanied by Franke, her keeper and a veterinarian.

In Cochrane, Bisitek will be reunited with Nikita and Aurora, who were donated to the Toronto Zoo in 2001.

Polar bears rarely live much past 30 years in captivity, although the oldest in Canada is believed to be 40 and living in Winnipeg.

The Toronto Zoo has begun the search for new polar bears. It expects to have a male and two females with hopes they will produce cubs when the revamped exhibit opens in 2009.

Curtis Rush Toronto Star, Staff Reporter



Timmins Daily Press

New polar bear for Cochrane
By Michael Peeling


The Cochrane polar bear family has a new addition from southern Ontario.

Finding herself without a home at the Toronto Zoo, 27-year-old female polar bear
Bisitek now hangs her hat at the Cochrane Polar Bear Habitat and Heritage Village,
where she will share space with twin females Nakita and Aurora, and male Nanook,
who is also 27.

Known to her keepers as "Bisi," they decided the aged bear should retire at the
Northern Ontario habitat now that the Toronto Zoo has closed its habitat for renovations.

For the next two years, Cochrane will be the only place in Ontario for the public to see polar bears.

The Cochrane habitat's director of conservation, Patricia Morin, says Bisi handled
the Aug. 20-move well.

"She slept the whole way from Toronto," Morin said. "It took us 25 minutes to wake her, but she's adapting well. She already knows how to shift from room-to-room."

Morin said the results of Bisi's blood work were good, a precaution taken to ensure
she doesn't bring diseases such as West Nile Virus up north.

A polar bear moving to a new location could be kept in quarantine for 30 to 42 days,
but Morin hopes Bisi will be ready to join the other three bears in the habitat before the next two weeks are up.

"We have to be careful not to let her out too fast," Morin said. "If we do, chances
are she'll just run to other side of the pen and stay away from the other bears.
Moving can be very stressful for a polar bear."

However, polar bears are naturally solitary animals according to Morin.
She said Bisi has actually flourished since her mate died a year-and-a-half ago.

The efforts to acclimate Bisi will include taking her through new routines used
at the habitat and making first contact with her peers through wire mesh.

"They need to get used to each other first," Morin said. "If we let them interact
with each other right away, the other girls might intimidate her."

The eventual meeting of three female bears will actually be a reunion because
Nakita and Aurora lived at the Toronto Zoo in 2001 before moving to Cochrane.

Bisi will have to adjust to living on grass as well - something she hasn't experienced since she was born in the wild - because the Toronto Zoo habitat is made up mostly of concrete slabs, and more snow in the winter.

She was orphaned in 1980 and saved by the Canadian Wildlife Service. Habitat spokeswoman Erin Van Alstine expects to see Bisi rolling around on the grass
a lot as she adjusts to the perks of the environment.

"At first you'll probably see a lot of hesitation from her," Van Alstine said.
"She'll be thinking, 'Do I? don't I?'"

Van Alstine anticipates a big spike in the number of visitors to the Cochrane
habitat now that the Toronto Zoo polar bear area is temporarily closed until fall 2009. As it stands, the Toronto Zoo isn't planning on having Bisi back once renovations are completed.

"Right now the plan is to keep her here during her retirement," Morin said.

"It's not good to keep moving polar bears, but ultimately it's up to the Toronto Zoo."




Photos by Urso Branco

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Two-thirds of the world's polar bears will be killed off by 2050

Two polar bears on a chunk of ice in the arctic.

Global warming to decimate polar bears: scientists

Updated Sat. Sep. 8 2007 2:30 PM ET

Associated Press

WASHINGTON -- Two-thirds of the world's polar bears will be killed off by 2050, including the entire population in Alaska, because of thinning sea ice from global warming in the Arctic, government scientists forecast Friday.

Only in northern Canada and northwestern Greenland are polar bears expected to survive through the end of the century, said the U.S. Geological Survey, which is the scientific arm of the Interior Department.

USGS projects that polar bears during the next half-century will lose 42 per cent of the Arctic range they need to live in during summer in the Polar Basin when they hunt and breed.

Polar bears depend on sea ice as a platform for hunting seals, which is their primary food. They rarely catch seals on land or in open water. But the sea ice is decreasing due to climate change and the latest forecasts of how much they are shrinking are, if anything, an underestimate, scientists said.

"There is a definite link between changes in the sea ice and the welfare of polar bears," said USGS scientist Steven Amstrup, the lead author of the new studies. "As the sea ice goes, so goes the polar bear."

Scientists do not hold out much hope that the buildup of carbon dioxide and other industrial gases blamed for heating the atmosphere like a greenhouse can be turned around in time to help the polar bears anytime soon.

"Despite any mitigation of greenhouse gases, we are going to see the same amount of energy in the system the next 20, 30 or 40 years," Mark Myers, the USGS director, said.

Greenland and Norway have the most polar bears, while a quarter of them live mainly in Alaska and travel to Canada and Russia. The agency says their range will shrink to no longer include Alaska and other southern regions.

The findings of U.S. and Canadian scientists are based on six months of new studies, during which the health of three polar bear groups and their dependency on Arctic sea ice were examined using "new and traditional models," Myers said.

USGS issued nine separate reports on polar bears Friday. Those included projections for one group of polar bears in the Southern Beaufort Sea and two in Canada that are among 19 distinct subpopulations.

They were made public to help guide Interior Secretary Dirk Kempthorne's decision expected in January on his agency's proposal to add the polar bear to the government's endangered species list.

USGS declined to provide precise estimates of polar bear populations 50 years from now.

A separate organization, the World Conservation Union, based in Gland, Switzerland, has estimated the polar bear population in the Arctic now is about 20,000 to 25,000, put at risk by melting sea ice, pollution, hunting, development and tourism.

Last December, Kempthorne proposed designating polar bears as a "threatened" species deserving of federal protection under the Endangered Species Act, because of melting Arctic sea ice from global warming. That category is second to "endangered" on the government's list of species believed most likely to become extinct.

That action is in response to a lawsuit in 2005 by three environmental groups - the Center for Biological Diversity, Natural Resources Defense Council and Greenpeace - to force such a proposal from Interior's Fish and Wildlife Service, which oversees endangered species.

The fate of polar bears has struck a public nerve. Fish and Wildlife officials have received 600,000 public comments so far on the proposed listing, spokesman Chris Tollefson said.

On Friday, Representative Edward Markey (D-Mass.), urged President George W. Bush's administration to grant polar bears federal protection.

"This is becoming a tragic metaphor for the administration's voluntary approach to global warming," said Markey, chairman of the House Select Committee on Energy Independence and Global Warming. "Instead of meeting the challenge, the Bush administration is happy to float along, waiting to see if the planet, and polar bears, will sink or swim."

From CTV News.

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Knut Photo Gallery

On December 5, 2006 Knut was born in the Berlin Zoo. His mother abandoned him so the zoo trainer adopted him. He plays with Knut daily and at first he slept with Knut. The kids in Berlin adore Knut.

You can see several videos of Knut at:

http://blog.rbb-online.de/roller/knut/category/Knut+international

http://blog.rbb-online.de/roller/knut/category/Videos+von+Knut

http://www.rbb-online.de/knut/


Now we will show you many photos of Knut starting with his birth.



Sleeping in the Incubator.




Warm and safe.




Feeding time.




Resting with friends.





Play time!




Knut's mom




Cuddly Knut




A sweet Baby.




Here I am world!!!





A head scratch feels good.





A sweet face!




Tender loving care.





First steps.


A gift from Canada.




This Canadian Ball is lots of fun.





A nap for Knut.




Wake up!





Looking around.






Maybe I will sleep some more.





A handsome fellow.




Getting big.





A back scratch is great.




Fishing fun!





Playing with my best friend!





This tastes good!


All Knut photos from Knut's website and Der Spiegel

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Proposal to List Polar Bears as Threatened

PROPOSAL TO LIST POLAR BEARS
AS THREATENED

From Panda Mail, Jan 31, 2007

WWF-Canada praises the recent proposal by the U.S. Fish and Wildlife Service to list the polar bear as “Threatened” under the U.S. Endangered Species Act. WWF-Canada had supported the petition to classify the species as Threatened, based on a large volume of very compelling information about significant changes to the polar bear's habitat - the Arctic sea ice. This ocean habitat is vanishing as a result of warming air and sea temperatures over the last decades, caused by the burning of fossil fuels. For more on this recent decision, or to learn more about polar bears in Canada, go to wwf.ca.

Read More, See More Photos and Read the Comments . . . CLICK HERE

You can help save the Magnificent Polar Bear

Urgent Notice:

Polar Bears are now on the
World Conservation Union's Red List
of Threatened Species.

A report from WWF-Canada

We saw it coming. The reality is now here.

Global warming will result in an alarming decline in polar bear populations within 45 years. The World Conservation Union, a global network of government, non-government and scientific organizations including WWF, recently determined that there is now an even greater risk of extinction of this magnificent species, almost two-thirds of whom are found right here in Canada.

There are several threats plaguing our nation's polar bears today - pollution and industrial development among them.

But none is greater or more challenging than the catastrophic effects of global warming on the polar ice cap, the polar bear's only home.

It seems there's no refuge from global warming -
not even in our great north.

The polar bear, the world's largest terrestrial carnivore, spends much of its life on the frozen sea. They depend on it to reach seals, their main prey. After they feed, the sea ice melts and they come ashore until fall. Their stored body fat must sustain them during the long fast on land.

However, with increasing levels of carbon dioxide and other heat-trapping gases in the atmosphere from the burning of fossil fuels, global temperatures are on the rise. This is causing arctic ice to melt earlier in the spring and form later in the fall.

This leaves polar bears less time to hunt to build up their essential body fat. This has meant starvation for some bears and their young cubs, and even drowning as a result of having to swim too far to reach food. And it will only get worse if we do nothing now.

The troubling facts speak for themselves.

Did you know . . .

- There are now reports of polar bears eating each other to survive in the Russian Arctic

- The summer of 2005 saw the smallest extent of sea ice ever

- Fewer than 25,000 polar bears remain in the wild today

- The Western Hudson Bay polar bear is facing extinction in our children's lifetime

If the warming trend continues unabated, scientists believe polar bears may disappear completely within 100 years.

Imagine. A species that has survived hundreds of thousands of years - and one that is the very symbol of our country's northern wilderness - snuffed out by the time our great grandchildren reach retirement.

But there is hope, you and I stuill have time to stop this horrific and preventable loss.

For our polar bears - and every living thing - support
the WWF-Canada fight against global warming.

Canada's polar bears are just some of the living treasures threatened by global warming. I can name countless others - birds, fish, entire forests and lakes, Nor will humans escape the ravages (look no further than the extreme weather events occurring all around us)!

Climate change is a crisis with very local and personal consequences. And it truly needs to be fought on every scale - local, regionally and globally. There are a number of important changes we, as individuals, can make in the fight against climate change. But a problem of such global proportions requires an equally global organization to tackle it. That's where we come in.

WWF's scope reaches the very top levels of private companies and governments - the organization that must make the most significant contributions in the battle against climate change.

Your donation today at (www.wwf.ca/climate) will increase WWF's ability to save life everywhere.

So what will your support allow WWF to do? Simply, to set up action on the following critical initiatives>

- Protecting fragile ecosystems. WWF fights for the protection of critical natural areas, including the boreal forest, which absorbs an enormous amount of greenhouse gases.

- Influencing government on your behalf. WWF works with governments at all levels to initiate laws and agreements to reduce energy use . . . encourage the development of clean and renewable energy sources like wind and solar . . . and WWF will do everything necessary to ensure Canada meets its international obligations to reduce greenhouse gases.

- Ensuring industry plays its part. WWF partnership with companies like Sony, Johnson & Johnson and others is helping reduce energy consumption while introducing new clean energy into corporate opeartions.

Help stop the neglect of our planet.

Our planet is suffering from decades of neglect. But together we can be the first generation to stop the downward cycle.

As a personal supporter of WWF-Canada I urge you to visit their website and make a donation to help our fight against global warming.

Visit their website www.wwf.ca/climate


Urso Branco


This report was excerpted almost in its entirety from a mailing report from WWF-Canada

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International Polar Year

Canadian taking lead in International Polar Year

Updated Thu. Mar. 1 2007 3:44 PM ET

Reprinted from CTV.ca News Staff, Toronto Canada


Thursday marked the official start of International Polar Year (IPY) 2007-2008, a worldwide program that will be the most intensive period of research on the polar regions in half a century.

More than 50,000 scientists from 63 countries will be conducting and sharing research during the two-year program, assessing the Arctic and Antarctic and making forecasts and recommendations for the future.

Canada will be spending $150 million to fund 44 research projects with the IPY-- the most of any participating country. All the projects are aligned with one of two priority areas:

* climate change impacts
* and adaptation and the health and well-being of Northern communities.

"Changes in the Arctic due to climate change are a signal, an early warning to Canadians," Environment Minister John Baird said in announcing the funding.

"These projects will give us a better understanding of the effects of climate change and other pollution falling on the North and that will lead to further actions we need to protect our water, land and citizens."

The largest of Canada's projects is being led by Dr. David Barber from the University of Manitoba, who is conducting a study called the Circumpolar Flaw Lead (CFL) System Study.

The project includes 200 scientists from around the world studying the "flaw lead" system, a circumpolar phenomenon created when the central Arctic ice pack moves away from coastal ice, leaving areas of open water.

The IPY takes place every 50 years. The first, in 1882-83, saw researchers from 11 countries establishing research stations around the Arctic and provided the foundation for much of the polar science knowledge we have today. During the last IPY in 1957-58, climate change and its effects on the poles were just emerging as a scientific issue.

Fifty years later, the devastating effects of global warming are becoming even clearer. What's more, scientists are armed with much better technology, especially satellites to study polar regions, known as the cryosphere.

"Often we study parts or pieces of the system, but IPY provides an opportunity to put the picture together as a whole," David Hik, Executive Director of the Canadian International Polar Year secretariat, told Canada AM Thursday.

"This year, all disciplines will be included. So they'll be looking at the climate, they'll be looking at permafrost, wildlife and polar bears and treeline changes. And most importantly, what we're calling the human dimension of change in the polar regions."

Arctic population health projects led by specialists at Laval University in Quebec will receive a lion's share of the federal funds.

"It will benefit the people of the North, the residents who are being affected by rapid change," Hik says.

Canadian researchers will also be participating in studies of polar bears, the disappearing permafrost and Arctic glaciers and the ecosystem in Yukon's Kluane National Park.

Hik said what also distinguishes this IPY from previous is that "the world is paying attention to the polar regions now."

"We know that the changes occurring there affect the rest of the planet," Hik said.

"And there's a great deal of interest in both the Arctic and the Antarctic as the sort of 'switch' that could have the greatest effect on the planet."

The world's top climate scientists said in a United Nations report last month that "average Arctic temperatures increased at almost twice the global average rate in the past 100 years."

They projected that sea levels could rise by 18 to 59 cm by 2100, by when Arctic sea ice may disappear in summers.

International researchers plan to try to quantify the amount of fresh water leaking out from underneath ice sheets in Antarctica, which takes place beneath the ice and has been difficult to measure.

Other projects include:

* the installation of an Arctic Ocean monitoring system, described as an early warning system for climate change;
* a census of the deep-sea creatures that populate the bottom of Antarctica's Southern Ocean.
* the mapping of the Antarctic's lakes and mountains -- some trapped under about ice for more than 35 million years; and,
* astronomers will investigate plasma and magnetic fields kicked up by the sun using telescopes, balloons and spacecraft.

The polar year is being sponsored by the UN's World Meteorological Organization and the International Council for Science. About $1.5 billion has been earmarked for the year's projects by various national exploration agencies.

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Tundra Buggy

The Fabulous Tundra Buggy

HISTORY

The company behind the original polar bear experience.

In 1979 the Tundra Buggy® Adventure, originally known as Tundra Buggy Tours Ltd., began conducting polar bear tour trips from Churchill, Manitoba to the frozen tundra, some thirty kilometers away. From the safety and comfort of a Tundra Buggy, visitors were able to get closer than anybody had been before to the majestic polar bear. What began with historic Buggy #1 and an elite group of photographers and adventure seekers has grown to a world-class Adventure!

Photographing the polar bears of Churchill has been established as a cornerstone to any serious photographer's portfolio and experiencing them has become an important notch on any real adventurer's belt.

In a process that began four years earliers, in 2003 Merv and Lynda Gunter, owners of Canadian North adventuring company, Frontiers North® Adventures, assumed majority
ownership of Churchill's Tundra Buggy company.

Since the involvement of Frontiers North, The Tundra Buggy Adventure has evolved into a company not only known internationally for providing amazing and intimate polar bear tours to Gordon Point and Cape Churchill, but is now also known internationally as a leader in Canada's
Ecotourism industry, with strong company ethos generating global awareness about Churchill's polar bears through groundbreaking initiatives like The Polar Bear Cam and leading support roles in initiatives like Polar Bears International's Polar Bear Leadership Camp and Videoconference Classroom.


Imagine this problem: out on the tundra, in close proximity to where you are, the fearsome Lord of the Arctic (better known as a polar bear) is roaming freely, just waiting for the Bay to freeze over so that he can get out and start hunting seals, his very favourite feast. Now imagine someone comes to you and says that he would like to get out there - on the tundra - where the bears are freely roaming - so that he can get some 'close up' pictures of these Lords.

Now parked in front of you is this huge wheeled - I mean huge, like 5 feet high huge, wheeled vehicle. Sitting on top of the wheels is this huge, I mean huge, wide-bodied enclosure. The vehicle includes a propane heater, a toilet facility and, for all intent and purposes, comfortable
seats, windows (that open) and a large observation deck.

Alas, now you have a Tundra Buggy that allows you to go out on the tundra, in relative comfort and safety to watch and photograph polar bears!

For more information go to the sidebar.

See link in the sidebar - Important Links: Tundra Buggy

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Recent History of Polar Bears

What has been happening to polar bears in recent decades?

Polar Bear Ongoings

Polar bears have long captured the attention of the general public but probably at no time in the past have they been more in the forefront of the public's imagination than today. Today's heightened interest in polar bears may be due in part to an enhanced understanding of the ecology of polar bears, their environment, and an increased interest in Arctic issues brought on by concerns for climate change. Results of years of research and studies are now available to an interested public, and efforts to communicate this information to the public has been more effective in recent years than in the past. As a result the current public is generally well-informed and educated regarding the ecology of polar bears. This public, unlike previous publics, has a variety of communication tools that enable it to interact and communicate more effectively with researchers and managers.


Polar bear distribution

What have we learned? We now know that polar bears are not a single large homogeneous population that roams throughout the Arctic. Instead groups of polar bears referred to as stocks or populations, are distributed throughout the Arctic. Research begun in the late 1960s and continuing today also provides a thorough backdrop of information on population demographics, systematically analyzed data on population boundaries, population movements, population size, reproductive and survival parameters, and other useful information about biological, physiological, and ecological aspects of polar bears.

We also realize that polar bears do not occur in large numbers; their ability to replace individuals in the population is very limited and population growth is extremely slow; they are long-lived creatures, which helps to offset the low reproductive potential; their populations fluctuate in response to natural factors such as climate and prey availability; and, populations can also be impacted by humans through factors such as hunting, oil spills, shipping, and other activities. We also realize that the level of human presence and activity in the Arctic continues to build. As a result the potential for humans to impact polar bears has never been greater than today.

Technologically, researchers have been blessed in the last 30 years. Advances in satellite telemetry allowed researchers to follow individual bears over time and greatly enhanced our knowledge of movements and population bounds. Infrared thermal sensory equipment is providing promise in detecting polar bear dens beneath the snow. Extended time-series of data now available for some populations documents trends that were previously not apparent. Improvements in aircraft and vessel transportation have provided access to a larger portion of the range of polar bears than was previously accessible. Finally, technologic advances have allowed for multi-disciplinary Arctic research, which is in many cases supported by polar-class icebreakers. All of these advances plus greater understanding of population dynamics and population modeling now allow for greater precision in making management decisions and a better understanding of risks and consequences of management actions.

In the past, one of the greatest saving graces for polar bear populations was the fact that their habitat was relatively pristine and secure from alteration. In fact a very large portion of the high arctic was void of any human presence. Hence at that time the greatest concern for polar bear populations were over harvest and human development that was occurring at the fringes of the range of polar bears.


Changes in sea ice extent over the past 25 years

Polar bears and their prey have evolved to living in the extreme conditions of the Arctic. Polar bears and seals are dependent on sea-ice for foraging, resting, and reproduction. The Arctic ecosystem was shaped by climate and continues to be driven today by climate. Polar bears and ice seals, primarily ringed seals, serve as key indicators of the effects of climate change on the Arctic environment. Today, polar bear populations are facing threats previously unprecedented during recorded history in the Arctic. Recent climate change scenarios based upon modeling of climate trend data predict that the Arctic region will experience major changes in the upcoming decades. On the most drastic end of the spectrum one model predicts that the Arctic basin may be void of ice within 50 years. Other models have shown that ice thickness has decreased by 40% during the past 30 years and the average annual extent of ice coverage in the polar region has diminished substantially, with an average annual reduction of over 1 million square kilometers.

While the ultimate or progressively evolving effects of climatic change on polar bear populations is not certain, we do recognize that even minor climate changes could likely have a profound effect on polar bears. The following is from the IUCN/Species Survival Commission, Polar Bear Specialist Group (PBSG) web site and in summary indicates the following:

* Climate changes on prey species will have a negative effect on polar bears
o increased snow can result in reduced success in successfully entering seal birth lairs
o decreased snow or increased seasonal rain patterns could effect seal pupping by not providing adequate snow for construction of birth lairs or if rain fall by collapsing birth lairs thus reducing seal productivity
o prey reductions could effect polar bear condition and ultimately cub production and survival
* Changes that alter the period of ice coverage could affect distribution and impact polar bears
o bears may spend greater amounts of time on land
o extended use of terrestrial areas would ultimately effect physical condition of bears when forced to rely on fat stores
o decreased physical condition could effect production and survival
o bears using deteriorating pack ice may experience increased energetic costs associated with movements and swimming
* Denning could be impacted by unusual warm spells
o access to high quality denning areas may be limited or restricted
o use of less desirable denning habitat could have impacts on reproduction and survival
o rain or warming could directly cause snow dens to collapse or be opened to ambient conditions
o loss of thermal insulative properties in opened dens could affect litter survival

As a case in point, in Western Hudson Bay researchers have collected demographic information on polar bears since 1981. Over this time frame and location the sea ice breakup has been occurring earlier. The earlier breakup has been related to the poorer condition of polar bears and there is a correlation between the earlier breakup and a decadal scale pattern of warming air temperatures during the spring between 1950 and 1990. It appears that earlier breakup caused by warmer temperatures has resulted in declines in physical and reproductive parameters of polar bears in this area. This is the only study to date to demonstrate the effects of changed environment resulting from climate changes, and a corresponding effect on polar bears. Climate change is not uniform in all areas of the Arctic, however. Since Hudson Bay is located at the southern most extent of the range of polar bears, findings here may be a forewarning of changes to come in future years for other areas of the Arctic. Clearly, climate change and its effect on sea ice and polar bears should be closely monitored in future years.

Environmental contaminants in the form of persistent organic pollutants (POPs) pose an additional area of increased concern for polar bears. Recent documentation of baseline contaminant levels in the circumpolar environment and in key species has dramatically expanded the knowledge of regional presence and levels of these pollutants over the past 10 years. Polar bears, as an apical predator that tends to amplify the accumulation organochlorines compounds, are a perfect candidate for studies in evaluating trends. We now know that polar bears inhabiting certain areas of the Arctic exhibit elevated levels of organochlorines, particularly PCB's (poly chlorinated biphenyls) while populations inhabiting other areas have lower levels. Laboratory experiments involving elevated levels of organochlorines have been associated with a range of effects including neurological, reproductive, and immunological changes. Studies are continuing to evaluate the effect of persistent organic pollutants on essential life functions of polar bears and other marine animals with an emphasis on evaluating immune and hormonal systems.

International involvement in polar bear conservation dates back to 1965 when scientists from Canada, Norway, Denmark, USSR, and the United States met in Fairbanks to discuss polar bear conservation due to widespread concern that populations were being over harvested. Until this time there had been very little management of polar bears in the Arctic and no coordinated effort among arctic countries. Harvest rates were rising rapidly in most areas except Russia which had enacted a ban on hunting in 1956. The Fairbanks meeting resulted in the formation of the IUCN/SSC Polar Bear Specialist Group (PBSG) whose mission was to coordinate polar bear research and management programs on an international basis and to exchange information on each country's programs.

Members of the PBSG and the countries they represent developed and negotiated the International Agreement on the Conservation of Polar Bears (Agreement), which was signed in Oslo, Norway in May, 1973. Among other conditions the Parties agreed through Article VII to "conduct national research programs on polar bears, particularly research relating to the conservation and management of the species. They shall, as appropriate, coordinate such research with the research carried out by other Parties, consult with other Parties on management of migrating polar bear populations, and exchange information on research and management programs, research results, and data on bears taken." The PBSG meets every three to five years with a goal of advancing the principles of the Agreement. The most recent meeting was held June 2001 in Nuuk, Greenland. The proceedings of the working group meetings are published in the IUCN series.

Highlights of recent activities include: conducting ecotoxological studies to evaluate potential effects on polar bear immune and hormone systems in the Svalsbard Island complex; continuing efforts to refine population boundaries and better understand sustainable harvest levels or the effects of harvests on populations; evaluating new techniques to conduct aerial population surveys; evaluating the relationship between bears, seals, and sea ice conditions; population genetics studies; and research to evaluate the effectiveness of thermal sensory technology to detect polar bear dens beneath snow; and.

The IUCN PBSG recently developed a web site that can be located at http://pbsg.npolar.no. This site includes a wealth of information including presentations from the last meeting, at Nuuk, Greenland, June 2001, population status and trends, a summary of the main issues facing polar bears (climate change, development, contaminants, and hunting), polar bear life history facts, members list and contacts, and a list of other pertinent links.

Gallery of Polar Bear Photographs

* Please visit the gallery of polar bear photographs, provided by the author, at http://www.arctic.noaa.gov/gallery_polarbear.html

* Another gallery of polar bear photographs is provided by Kathy Crane from NOAA's Arctic Research Office

* Web cam photos and video of polar bears from polarbearcam.com

References

General Biology and Organizations
International Association on Bear Research and Management
Polar Bears International (formerly Polar Bears Alive)
U.S. Geological Survey
U.S. Fish and Wildlife Service

Climate Change
Intergovernmental Panel on Climate Change
Arctic Council (International Arctic Science Committee)
Bering Sea Impact Assessment - Alaska
Barents Sea Impact Study - Norway
United Nations Framework Convention on Climate Change
Arctic Monitoring and Assessment Program

Contaminants
Stockholm Convention on Persistent Organic Pollutants
U.S. Environmental Program Persistent Organic Pollutants
Canada: Northern Contaminants Program


Author:

Scott L. Schliebe
Polar Bear Project Leader
U.S. Fish and Wildlife Service/MMM
Anchorage, AK


See link in the sidebar - Important Links: National Oceanic and Atmosphere Administration

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Polar Bear FAQ

Polar Bear FAQ from Polar Bear International

1 - Where do polar bears live?
2 - Are polar bears endangered?
3 - How many polar bears are there?
4 - What is the polar bear's scientific name?
5 - How big are polar bears?
6 - What adaptations have polar bears made to their environment?
7 - What do polar bears eat?
8 - What is the polar bear's place in the food chain?
9 - What is a polar bear's life span?
10 - How many cubs does a female bear have?
11 - When and where are the cubs born?
12 - What do the cubs look like?
13 - When does the family emerge from the den?
14 - How long do the cubs remain with their mother?
15 - Do polar bears hibernate?
16 - Are there different populations of polar bears?
17 - Does the polar bear have any enemies?

1 - Where do polar bears live?

Polar bears range throughout the circumpolar north in areas where they can hunt seals at open leads. The five "polar bear nations" in which the bears are found include the U.S. (Alaska), Canada, Russia, Denmark (Greenland), and Norway.

Polar bears do not live in the southern hemisphere.

2 - Are polar bears endangered?

Polar bears are a potentially threatened species rather than an endangered one. A threatened species is one that could easily become endangered in the foreseeable future.

The major threat to the polar bear is climate change. Other threats include pollution, poaching, and industrial disturbances. Hunting could become a threat if populations are not well managed.

The U.S. Fish and Wildlife Service has proposed that polar bears be added to the Threatened Species list under the U.S. Endangered Species Act. Canada and Russia both list the polar bear as "a species of concern." In 2005, the world's leading polar bear scientists reclassified the polar bear as vulnerable on the IUCN World Conservation Union's "Red List of Threatened Species," noting that the species could become extinct due to sea ice changes.


3 - How many polar bears are there?

Scientists estimate that there are between 22,000 to 27,000 polar bears.


4 - What is the polar bear's scientific name?

Ursus maritimus or the "sea bear." Its closest relative is the brown bear.


5 - How big are polar bears?

Adult male polar bears measure 2.5 to 3 meters (8 to 10 feet) tall. They weigh 250 to 770 kilograms (550 to 1,700 pounds). Adult female bears are smaller. They measure 1.8 to 2.5 meters (6 to 8 feet) tall and weigh 90 to 320 kilograms (200 to 700 pounds).


6 - What adaptations have polar bears made to their environment?

Polar bears are perfectly adapted to survive in the harsh conditions of the Arctic, where winter temperatures can plunge to -45° C (-50° F). Two layers of fur provide the bears with such good insulation that they experience almost no heat loss. In addition, they are protected with a layer
of blubber that can measure 11.5 cm (4.5 inches) thick.

Compact ears and a small tail also prevent heat loss. Polar bears are so well protected from the cold that they have more problems with overheating than they do from the cold. Even in very cold weather, they quickly overheat when they try to run.

Other adaptations include small bumps called papillae that keep their feet from slipping on ice; strong, powerful claws that enable them to catch seals; and a nose powerful enough to detect prey that is miles away.


7 - What do polar bears eat?

Seals are the polar bear's primary prey, particularly the ringed seal and, sometimes, the bearded seal. When hunting is good, polar bears will typically eat only the fat and leave the rest of the carcass for scavengers including arctic foxes, ravens, and younger bears.

Polar bears also sometimes kill and eat both walrus and beluga whales. They have been known to hunt short-legged reindeer and sometimes snack on other foods including birds, bird eggs, kelp, and beached whales. On Norway's Svalbard Islands, polar bears were once found feasting on a 350-year-old bowhead whale carcass that was uncovered by a retreating glacier.


8 - What is the polar bear's place in the food chain?

Polar bears top the food chain in the Arctic. They help keep the balance of nature by preventing an overpopulation of seals.


9 - What is a polar bear's life span?

In the wild, polar bears live an average of 15 to 18 years, although biologists have tagged a few bears in their early 30s. In captivity, they may live until their mid- to late 30s. One zoo bear in London lived to be 41.


10 - How many cubs does a female bear have?

There are usually two cubs in a litter. Female polar bears have their first set of cubs between the ages of four and eight (most frequently at age five or six). Polar bears have the one of the slowest reproductive rates of any mammal, with females typically producing five litters in their lifetime. (See more about cubs.)


11 - When and where are the cubs born?

Polar bear cubs are born in snow dens called maternity dens. In the late fall, a female polar bear will dig a den after feeding heavily in April or May. Most choose den sites in snowdrifts along mountain slopes or along hills near the sea ice. Some dig their dens in snow drifts out on the sea ice.


12 - What do the cubs look like?

At birth, the cubs are 30 to 35 centimeters (12 to 14 inches) long and weigh little more than half a kilogram (about a pound). They are blind, toothless, and covered with short, soft fur. They are completely dependent on their mother for warmth and food.


13 - When does the family emerge from the den?

The cubs are born in November or December and remain in the den until March or April. During that time, the mother does not eat, drink, or defecate. The cubs grow rapidly while they are in the den, thanks to the calories in their mother's rich milk, which has a fat content of roughly 31%.


14 - How long do the cubs remain with their mother?

Polar bears cubs normally stay with their mother until they are 2 1/2 years old, although some bears in the Hudson Bay area wean their young at age 1 1/2. During the time that the cubs are with their mother, they must learn how to hunt and survive in one of the Earth's harshest environments.


15 - Do polar bears hibernate?

Polar bears do not hibernate in the true sense of the word. True hibernators experience a marked drop in heart rate and a body temperature that plunges to nearly 0° C (32° F).

Polar bears do not enter a state of deep hibernation; instead they undergo "walking hibernation." Only pregnant female bears enter a den. They do so in the fall and give birth to their cubs in November or December. The bear family will remain in the den until March or April.


16 - Are there different populations of polar bears?

Scientists recognize nineteen distinct populations of polar bears, but no subspecies.


17 - oes the polar bear have any enemies?

Only humans and, on rare occasions, other polar bears.

Climate change is the biggest threat that the bears face.

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More Polar Bear FAQ

Frequently Asked Questions about polar bears

1. What does the Latin name "Ursus maritimus" mean?
2. How many species of bears are there besides polar bears and where do they live?
3. How many polar bears are there in the world?
4. How far south can we meet polar bears – and how far north?
5. How large do polar bears get?
6. What is the basics of polar bear life history?
7. What do they eat?
8. Some say that polar bear fur have fiber-optic qualities. Is this true?
9. What is trichinosis?
10. How are they adapted to a cold and wet environment as the Arctic?
11. Why are there no polar bears in Antarctica?
12. How far can they swim and for how long can they hold their breath?
13. How fast can they run?
14. How many polar bears are hunted, and where?

1 - What does the Latin name "Ursus maritimus" mean?

The name Ursus maritimus is Latin - "Ursus" means "bear" and "maritimus" means "sea". Thus "Ursus maritimus" can be translated into "bear of the sea".

2 - How many species of bears are there besides polar bears and where do they live?

There are 8 species of bears around the world:

BEAR SPECIES LATIN NAME DISTRIBUTION

Polar bear Ursus maritimus Arctic circumpolar

Sun bear Ursus malayanus Previously the entire southeast Asia, but today mostly in Indonesia and Malaysia, are now believed to be extinct in India and possibly Bangladesh.

Sloth bear Ursus ursinus Found in forests and grasslands in India, Sri Lanka, Bangladesh, Nepal and Bhutan.

Brown bear Ursus arctos North America and Eurasia, including Japan and former Soviet territories. The North-American brown bear is also called "Grizzly".

Black bear Ursus americanus North America

Spectacled bear Tremarctos ornatus South America, mostly within national parks in the Andes region, from Venezuela and Colombia southwards through Ecuador, Peru and Bolivia.

Asiatic black bear Ursus thibetanus Currently distributed in two large areas, one in southeast Asia, extending from Malaysia through The Himalayas as far as Pakistan, Iran and Iraq. The other group is found along the western Asian coast including Japan, Korea and the Russian Far East.

Giant Panda Ailuropoda melanoleuca The species is now restricted to six isolated mountain ranges in western China: Qinling in Shaanxi Province, Minshan in Gansu and Sichuan Provinces, and Qionglai, Xiangling and Liangshan in Sichuan Province.


3 - How many polar bears are there in the world?

Current estimate is 21.500-25.000. This estimate is arrived at by adding the individual estimates of the sizes of all the populations in the world. However, it is still only an estimate because, while the size of some populations, such as Western Hudson Bay, are quite well known, the size of others in Russia and East Greenland can only be guessed at. This review is done by the members of the Polar Bear Specialist Group for all the world’s ca. 19 populations, and it is done in connection with the regular meetings of the group. The last meeting was in Nuuk, Greenland, in June 2001, and the results from the population review updates are published elsewhere on these webpages.


4 - How far north can we meet polar bears – and how far south?

No reports have put polar bears exactly on the North Pole itself, but ca. 100 miles to the south, at 88°N. Thus, there is no doubt that there are polar bears in the vicinity of the North Pole, though they are probably not abundant because the ocean there is less biologically productive than it is over the continental shelf, at the edges of the polar basin and associated islands. There is little detailed knowledge about polar bear migrations in the Polar Basin, since there has been little research carried on there. The Arctic Ocean basin is among the earth’s most remote areas, and the logistics and cost of such studies are limiting factors. However, there are numerous reports from polar explorers and expeditions that have encountered occasional polar bears in the permanent ice cap around the North Pole.

The furthest south that polar bears live on a year-round basis are in James Bay in Canada, where bears den at about 53°N on Akimiski Island. On a seasonal basis some bears appear regularly as far south as Newfoundland, and they have occasionally been seen in the Gulf of St. Lawrence in years when heavy pack ice have been drifting farther to the south than normal (latitude 50°N).


5 - How large do polar bears get?

Adult males measure 240-260 cm and usually weigh 400-600 kg, although they can weigh up to 800 kg and maybe even more. They do not reach the maximum size until they are 8-14 years old. Adult females are about half the size of males and reach adult size at an age of 5-6 years, when most of them weigh 150-250 kg. Pregnant females can weigh up to 400-500 kg just prior to entering their maternity dens, but almost half of this is fat required to sustain themselves through winter.

Polar bears are the largest living carnivorous quadruped (animal with four legs).


6 - What are the basics of polar bear life history?

Polar bears have a normal life span of about 25 years for males and 30 for females, although a small number of individuals may live longer. In captivity, there have been a number of individuals that have survived for longer than 40 years of age.

The breeding season occurs in spring to early summer (March-June).

The number of cubs per litter is one or two, rarely three. Younger and older females often have only one cub, while 2 or even 3 cubs may be born to females between the ages of about 8 and 20. As for all mammals, the mortality of cubs is quite high, sometimes exceeding 70%. Cubs typically stay with their mother for 2.5 years, but in some areas where the marine ecosystem is less productive they may remain with their mothers for 3.5 and even 4.5 years. In Western Hudson Bay, variable numbers of cubs may be successfully weaned as yearlings. This means that in most parts of their range, females normally mate and gives birth every 3 years.

Both males and females become sexually mature around 4-5 years of age. Females normally give birth at sexual maturity, but it is unlikely that males mate before they are 8-10 years old.


7 - What do polar bears eat?

The main part of the polar bears’ diet is ringed and bearded seals. Ringed seals, often the pups, are caught in the ice, either by smashing through the ice and grabbing newborns in the birth lair, grabbing them after waiting by their breathing hole, or by stalking the seals on the ice. Polar bears also prey on a wide variety of other marine mammals, depending on their availability, including walrus (pups), harp seals, hooded seals, white whales (belugas), narwhal, When on land they have been known to eat Svalbard reindeer, seabirds, geese, and eggs of eider ducks as well as scavenging on the occasional whale carcass. They have also been known to eat berries, grass, and dive for kelp.


8 - Some say that polar bear fur have fiber-optic qualities. Is this true?

No. Polar bear hair does not have fiber-optic properties. It has been postulated that the fur could channel light to the skin, but this was proven to be false (for more information about this issue, you can visit the homepage of Daniel Koon of St. Lawrence University).


9 - What is trichinosis?

Trichinosis is a parasitic disease that you might be infected with if you eat pork or polar bear meat that is not thoroughly cooked. The parasite, Trichinella sp., is a roundworm in the order Nematoda. After the larvae is ingested through infected meat, they are released, reach maturity, and mate in the bear's intestines. The female parasites produce live larvae. The parasites are then carried from the gastrointestinal tract by the bloodstream to various muscles, where they become encysted. It is estimated that 10% to 20% of the adult population of the United States suffers from trichinosis at some time. In many people the disease exhibits no symptoms and is discovered only at autopsy. In others it causes diarrhea and other gastrointestinal symptoms as the worms multiply in the digestive tract. When the larvae circulate through the bloodstream, the patient experiences edema, irregular fever, profuse sweating, muscle soreness and pain, and prostration. There may be involvement of the central nervous system, heart, and lungs; death occurs in about 5% of clinical cases. Once the larvae have imbedded themselves in the muscle tissue, the cysts usually become calcified; however, the infestation usually causes no further symptoms except fatigue and vague muscular pains. There is no specific treatment.


10 - How are they adapted to a cold and wet environment as the Arctic?

Polar bears are marvelously adapted to their arctic surroundings. Their thick winter coats, with glossy guard hairs and dense under-fur, and the thick layer of fat beneath their skin protect them against the cold. The guard hairs also shed water easily, so that after a swim the polar bear can shake itself like a dog to decrease chilling and to dry itself fairly quickly. Being large also helps keep warm.

The white color of the polar bear also serves as camouflage. Polar bears are clever in their use of cover, be it land, water, or ice. This aids both their hunting of seals and their own escape from human hunters. The soles of the bears’ feet have small bumps and cavities that act like suction cups which help to keep them from slipping on the ice.

Probably the most significant adaptation of polar bears to the uncertainties of food availability in the Arctic is their ability to slow down their metabolism (in order to conserve energy) after 7-10 days of not being able to feed, for whatever reason and at any time of year, until food becomes available again. In comparison, black or brown bears can slow down their metabolism only in response to not feeding in the late fall, just before they enter their dens for the winter. If food is removed from black or brown bears in spring or summer when they are not in their winter dens, they will simply starve to death.


11 - Why are there no polar bears in Antarctica?

The distribution of all animals is a function of luck and history. Having everything you need is no guarantee of being able to reach any point on the globe once you are there because it may not be possible to get there in the first place.

Polar bears likely evolved very recently (about 200,000 years to possibly as long as 500,000 years ago) from grizzly bears somewhere off eastern Russia or the Alaskan Panhandle. They are totally dependent upon sea ice for their primary habitat for getting their food (mainly ringed seals and bearded seals). As the world's oceans never have been frozen from the north to the south, polar bears never have had the possibility to reach the Antarctic. Polar bears are strong swimmers but not strong enough to swim to the Antarctic.

Some species have wider distributions because their habitats were connected at some time in the distant past. For example, grizzly bears (also called brown bears) live in the USA, Canada, Russia, Spain, Italy and even Norway! They crossed over a land bridge between Russian and Alaska. The same is true for wolves, wolverines, lynx and many other species.

However, polar bears would really like the Antarctic. In the absence of polar bears, seals and penguins in the Antarctic are not afraid of predators (except leopard seals and killer whales). A polar bear would have a lot of fun and probably get very very fat! On the negative side, the seals and penguins would be devastated. Polar bears are really better off in the Arctic.


12 - How far can they swim and for how long can they hold their breath?

Polar bears can swim steadily for many hours in order to get from one piece of ice to another. They have water-repellent coat and partially webbed feet, which both are adaptations to swimming. Although known individual bears have only been recorded swimming about 100 km or so, they are likely capable of swimming much further if necessary. However, this kind of effort is very expensive in terms of energy, so swimming such long distances is likely not done frequently. The longest a polar bear in the wild has been timed holding its breath while diving is 72 seconds.


13 - How fast can they run?

Polar bears don't normally like to run for long periods, but on a good surface a polar bear can reach speeds of 30 km/h (or 20 mph).


14 - How many polar bears are hunted, and where?

The populations that are hunted are those in North America, Eastern Russia (Chukchi area) and Greenland. The populations in the Barents Sea and western and central Russian Arctic are not hunted.

Although quotas vary, and are set annually based on previous catch history and population assessments, the annual total world catch is about/less than 1000 bears. Most of these are taken by Inuit people in Canadian and US territories.

As a part of focus on sound management of all populations, a lot of attention has been given to try to get solid and representative statistics from the catch in each area. This has been problematic in a few of the populations (see: resolutions from the 2001 meeting of the PBSG in Nuuk, Greenland). Thus, there is some concern about the unknown size of the harvest in some areas, especially in Northeast Greenland, due to a suspected multiyear overharvest.



Author: IUCN/PBSG.
Copyright © 2001 IUCN/PBSG. All rights reserved.
Revised: juni 10, 2002 .

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National Geographic Feature on Polar Bears

Close-up Images of Polar Bears in National Geographic

A polar bear paparazzo brings back close-up images of these Hudson Bay celebrities.

Get a taste of what awaits you in print from this compelling excerpt.

Nosing into frigid wind a polar bear sniffs for prey. About 1,200 of these majestic carnivores haunt the western edge of Canada's Hudson Bay. Here near the southernmost tip of their range, they're treading on thin ice.

Like all polar bears, those on Hudson Bay need solid ice as a platform for hunting seals and seal pups, their main prey. Yet the bay is frozen only in winter and spring, so from July to November bears must live off their fat reserves. For millennia they've coped, but climate change may be tipping the balance. "Though there's considerable variation, spring breakup is two weeks or so earlier now than it was 20 years ago," says biologist Ian Stirling of the Canadian Wildlife Service. His data show that birthrate and adult bear weight are both down about 10 percent from 1980. "If the trend continues and the ice disappears from Hudson Bay," says University of Alberta biologist Andrew Derocher, "it's pretty clear that these bears will disappear too."

Even at subzero temperatures, polar bears retain virtually all their body heat. Two layers of fur and thick fat act as superb insulation.

A dozing bear won't lie for long as autumn blizzards hit. Snow, cold, and the promise of food will lure him toward Hudson Bay to stalk the winter ice. With ice tending to melt earlier in the spring, the winter hunt grows urgent.

Get the whole story in the pages of National Geographic magazine.


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History of the Polar Bear - Canadian Museum of Nature

Ursus maritimus

Polar bears probably diverged from brown bear ancestors near the Arctic coast of Eurasia early in the Ice Age. They may have evolved from coastal scavengers into active hunters of seals on sea ice. The oldest known fossil (nearly 70,000 years old) is from near Kew, England, and represents a bear much larger than those currently living.

Other fossils are from Hamburg, Germany, Yamal Peninsula (the former Soviet Union), and several sites in Sweden and Denmark. The species may have been known to Paleolithic artists, for what appear to be two polar bears are depicted on a wall in the cave of Ekain, near the northern coast of Spain.

Hence, polar bears appear to have decreased in size and retreated northward since the end of the last glaciation.

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Beringia Natural History Notebook - Ursus Maritimus

Polar Bear Ursus maritimus
Description

Only recently in evolutionary time have bears adapted to life on arctic seas, but these great creatures have mastered the water and ice environment superbly. Over time they evolved a luxuriant white coat and layer of blubber for camouflage and warmth. Oversize feet serve as paddles for extensive swimming and spread their weight, helping this largest of modern carnivores (excepting Orcas) to traverse ice too thin to support a person.


Evolution

During the Ice Age, seals adapted to life in icy northern seas. Their need to breathe and reproduce at the surface put a rich year-around food resource within reach of a population of brown bears that began to live more and more out on the ice. Natural selection favored those bears best able to catch seals, and they became more thoroughly carnivorous than other bears. By 100,000 years ago they had evolved into something like the polar bear of today. Although polar and brown bears now look and act rather differently, their genetic closeness is demonstrated by matings in zoos that produce fertile offspring.


Distribution and Abundance

Polar bears' range is circumpolar. A few have been spotted close to the pole, but heavy perennial ice there provides poor seal hunting, so most are found further south where the ice is thinner and less continuous.

Formerly it was believed that polar bears migrated freely all across the Arctic, but modern research suggests that there are actually a number of more or less distinct populations. Russian and American are investigating the possibility that Beringian bears comprise a single group which during winter is distributed from Wrangel Island south along the Asian coast and in the central Bering Sea as far as St. Mathew Island. In summer, those wintering in the Bering Sea return to the north with the retreat of pack ice. Beringian bears seldom mingle with another population found in the Beaufort Sea east of Pt. Barrow, Alaska.

In 1981 the IUCN Polar Bear Specialist Group agreed that the world population was between 20,000 and 40,000. As of 1988 the most accepted estimate for the Alaska populations was 3,000-5,000.


Life History

The "Arctic Ring of Life" is the name given by Soviet biologist Savva Uspenski to the system of polynyas, or lakes of open water in pack ice, that persist through the winter. Wind, upwellings and currents along some shores or downwind from islands bring nutrients to the surface here, and keep the sea ice from coalescing. The coastal shear zone between shore- fast ice and the moving pack is also rich for similar reasons. These areas are vital to marine mammals and migrating birds, and to polar bears, which often hunt in such places.

Ringed seals are the bears' principal prey. They also hunt bearded seals and occasionally the more dangerous walrus. Normally solitary hunters, they have an impressive range of strategies, learn quickly, and show immense patience, power and speed. It has been calculated that their caloric needs require one ringed seal every six and a half days. Arctic foxes live on the sea ice in winter by scavenging polar bear kills.

Since their prey is available year-round, polar bears do not hibernate like brown bears, except pregnant females, who spend about five months in dens to give birth to their cubs. The female must greatly increase her weight, mostly in fat, to carry off a successful pregnancy and denning. The cubs, usually two, are born in December or January, weighing only 0.5 to 0.9 kilograms (one to one and a half pounds). By the time the family breaks out of the den in March or April the cubs weigh 10-15 kilograms (25-30 pounds). Cubs generally remain with their mother for two and a half years. Females are therefore able to bear young only every three years. This low rate of reproduction is balanced by a long life and low rates of natural mortality.

Moving in autumn from drifting ice to suitable denning sites requires a remarkable and little understood navigational ability. An important denning area for the Beringia population is on Wrangel Island. Denning also occurs on the northeastern coast of Alaska, although a majority of the Beaufort population dens on sea ice.


Relationships with People

About 4,000 years ago the ancestors of present day Eskimos moved into an ecological niche not yet occupied by people: hunting marine mammals of the northern seas. Once they learned this life-style they spread quickly along Arctic coasts. They had discovered much the same niche as the polar bear and may even have learned from bears, for their seal hunting methods are strikingly similar.

Polar bears have a preeminent place in Eskimo cultural and spiritual life. The spiritual guardians of shamans were usually polar bears, and it was believed that the spirits of people and bears sometimes interchanged. Killing a bear was a major event, requiring ceremonial propitiation of its spirit. Sometimes it was the bear who killed the person, for the predator-prey relationship went both ways.


From:

Beringia Natural History Notebook Series - September, 1992
National Audubon Society
Alaska-Hawaii Regional Office
308 G. Street, Suite 217 Anchorage, AK 99501

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Ursus Maritimus (Polar Bear) - Wikipedia

Wikipedia has some interesting facts about Polar Bears

The polar bear (Ursus maritimus), also known as the white bear, northern bear, sea bear, or nanuq in some Inuit languages, is a species of bear that is native to the Arctic and the apex predator within its range.

Its thick blubber and fur insulate it against the cold, and its translucent fur, which appears white or cream-colored, camouflages it from its prey. The bear has a short tail and small ears that help reduce heat loss, as well as a relatively small head and long, tapered body to streamline it for swimming. The polar bear is a semi-aquatic marine mammal that depends mainly upon the pack ice and the marine food web for survival. It has uniquely adapted for life on a combination of land, sea, and ice and is now dependent on this combination.

Scientists now believe that the projected decreases in the polar sea ice due to global warming will have a significant negative impact or even lead to extinction of this species within this century. Population reductions of up to 20% have been recorded in recent years, the average weight of the bears has been declining significantly, and cub survival rates have plunged.




Physical description

Size and weight

Polar bears rank with the Kodiak bear as among the largest living carnivores, and male polar bears may weigh twice as much as a Siberian tiger. There is great sexual dimorphism, with some males reaching more than twice the size of the females. Most adult males weigh 300-600 kg (660-1320 lb) and measure 2.4-2.6 m (7.9-8.5 ft) in length. Adult females are roughly half the size of males and normally weigh 150-300 kg (330-660 lb), measuring 1.9-2.1 m (6.25-7 ft).[4][5] At birth, cubs weigh only 600-700 g or about a pound and a half.

The largest polar bear on record was shot in Kotzebue Sound, Alaska, in 1960. According to Guinness World Records 2006, this bear weighed an estimated 580 kg (1960 lb) and was 3.38 m (11 ft 11 in) tall when mounted.

Recent data, however, suggest that polar bear weights are declining, an indication of the current pressure on the bears. A 2004 National Geographic Society study showed that polar bears that year weighed, on average, fifteen percent less than they did in the 1970s. In 2007 the females in Hudson Bay averaged only 230 kg, down from near 300 kg in 1980.


Fur and skin

A polar bear's fur is translucent despite its apparent white hue, providing good camouflage and insulation. It may appear yellowish brown as they age. Its black skin has evolved to radiate heat out to its layer of thick fur, which helps keep the animal warm in the coldest weather. The bear has a black nose. Stiff hairs on the soles of its paws provide insulation and traction on ice.

Unlike other Arctic mammals, polar bears do not shed their coat for a darker shade in the summer. It was once conjectured that the hollow hairs of a polar bear coat acted as fiber-optic tubes to conduct light to its black skin, where it could be absorbed - a theory disproved by recent studies. The thick undercoat does, however, insulate the bears: they overheat at temperatures above 10 °C (50 °F), and are nearly invisible under infrared photography; only their breath and muzzles can be easily seen. These bears often sprawl upon the ice to cool off; on land, they may dig for the cooler permafrost layer beneath. Growing through the undercoat is a relatively sparse covering of hollow guard hairs about six inches long. These guard hairs are stiff, shiny and erect, and stop the undercoat from matting when wet. Water is easily shaken off before it can freeze. The bear also rolls in snow to shed moisture from the coat.

Evolution

Speciation

The raccoon and bear families are believed to have diverged about 30 million years ago. The spectacled bear split from other bears around 13 million years ago. The six distinct ursine species originated some 6 million years ago. According to both fossil and DNA evidence, the polar bear diverged from the brown bear roughly 200 thousand years ago; fossils show that between 10 and 20 thousand years ago the polar bear's molar teeth changed significantly from those of the brown bear.

Polar bears have, however, bred with brown bears to produce fertile grizzly–polar bear hybrids, suggesting that the two are close relatives. But neither species can survive long in the other's niche, and with distinctly different morphology, metabolism, social and feeding behaviors, and other phenotypic characters, the two bears are generally classified as separate species.

In a widely cited paper published in 1996, a comparison of the DNA of various brown bear populations showed that the brown bears of Alaska's ABC islands shared a more recent common ancestor with polar bears than with any other brown bear population in the world. Also to see how the bear species once split yet are still connected, polar bears still have HIT (hibernation induction trigger) in their blood, but do not now utilize this to hibernate as the brown bear does. They may occasionally enter a dormant state referred to as "denning" (pregnant females in particular), though their body temperature does not decrease during this period as it would for a typical mammal in hibernation.


Subspecies and populations

Many sources list no polar bear subspecies, while others list two - Ursus maritimus maritimus and Ursus maritimus marinus. The number of populations varies depending upon who is counting. The IUCN/SSC Polar Bear Specialist Group (PBSG), the pre-eminent international scientific body for research and management of polar bears, recognizes twenty populations, or stocks, worldwide. Other scientists recognize six distinct populations.

1. Chukchi Sea population on Wrangell Island and western Alaska
2. Northern and northwestern Alaska and northwestern Canada (the Beaufort Sea population)
3. Canadian Arctic archipelago
4. Greenland
5. Spitzbergen-Franz Josef Land
6. Central Siberia

Natural range

Though it spends time on land and ice, the polar bear is regarded as a marine mammal due to its intimate relationship with the sea. The circumpolar species is found in and around the Arctic Ocean, its southern range limited by pack ice. Their southernmost point is James Bay in Canada. While their numbers thin north of 88 degrees, there is evidence of polar bears all the way across the Arctic. Population estimates are just over 20,000.

The main population centers are:

* Wrangell Island and western Alaska
* Northern Alaska
* Canadian Arctic archipelago
* Greenland
* Svalbard-Franz Josef Land
* North-Central Siberia

Their range is limited by the availability of that sea ice they use as a platform for hunting seals, the mainstay of their diet. The destruction of its habitat on the Arctic ice threatens the bear's survival as a species; it may become functionally extinct within the century. Signs of this have already been observed at the southern edges of its range.


Hunting, diet and feeding

The polar bear is the most carnivorous member of the bear family, and the one that is most likely to prey on humans as food. It feeds mainly on seals, especially ringed seals that poke holes in the ice to breathe, but will eat anything it can kill: birds, rodents, shellfish, crabs, beluga whales, young walruses, occasionally musk oxen or reindeer, and very occasionally other polar bears. Still, reindeer and musk oxen can easily outrun a polar bear, and polar bears overheat quickly: thus the polar bear subsists almost entirely on live seals and walrus calves, or on the carcasses of dead adult walruses or whales. They are enormously powerful predators, but they rarely kill adult walruses, which are twice the polar bear's weight. Orcas, humans, and larger bears of their own species are the only predators of polar bears.

As a carnivore which feeds largely upon fish-eating carnivores, the polar bear ingests large amounts of vitamin A, which is stored in their livers; in the past, humans have been poisoned by eating the livers of polar bears. Though mostly carnivorous, they sometimes eat berries, roots, and kelp in the late summer.

Polar bears are crafty hunters and will wait by the breathing holes of the seals in the ice and wait for them to surface. Sometimes they crawl up to sleeping seals, stopping if the seal wakes, then resuming and finally leaping and catching them. Adult bears mainly eat the skin and blubber and leave the organs and muscle. This reduces the need for water as less urea is produced than from a high protein diet. In the winter, when water is hard to find, this helps save energy as well since they need to ingest less snow. They have lowest cholesterol levels when eating many seals, likely because of the plentiful omega-3 fatty acids in the seal blubber. Their cholesterol rises during fasting. Lactating females and young and growing bears will eat entire carcasses. Typically the normal adult bear will eat a seal every five days or so when their prey is most plentiful.

Polar bears are excellent swimmers and have been seen in open Arctic waters as far as 60 miles from land. In some cases they spend half their time on ice floes. Their 12 cm (5 in) layer of fat adds buoyancy in addition to insulating them from the cold. Recently, polar bears in the Arctic have undertaken longer than usual swims to find prey, resulting in four recorded drownings in the unusually large ice pack regression of 2005.

Polar bears are enormous, aggressive, curious, and extremely dangerous to humans. Wild polar bears, unlike most other bears, are barely habituated to people and will quickly size up any animal they encounter as potential prey. A polar bear should never be approached and if one is spotted, it is best to retreat slowly on foot to an indoor location, or leave in a vehicle.

Like other bear species, they have developed a liking for garbage as a result of human encroachment; the dump in Churchill, Manitoba is frequently scavenged by polar bears, who have been observed eating, among other things, grease and motor oil.


Breeding

The polygamous polar bears mate in the spring (March to May); pairing only lasts for the actual mating with few permanent bonds observed. Testosterone levels increase in the spring for the males and the testicles increase in size. Once fertilized the females ova undergoes a delayed implantation, which takes hold in September or October. The gestation period is between 195 and 265 days (about 8 months) with the cubs born soon after the ova implant in early winter (November to December).

The mother digs a two-chambered cave in deep snow for the birth in October after a period of heavily feeding. Usually, two cubs are born, less often one or three; litters of four cubs have been recorded. Like other Ursus bears, the new cubs are tiny, typically 30 cm long and weighing 700 g (a pound and a half), compared to their sometimes 300 kg (660 lb) mothers. The helpless and blind cubs open their eyes after about a month, emerge from the den at about 10 kg (22 lb), are able to walk at 1.5 months, and start eating solid food at 4-5 months. They remain with their mother, learning to hunt and protect themselves against adult males, which sometimes cannibalize cubs.

Females nurse their young for up to two and a half years on milk that contains approximately 33% fat, higher than that of any other species of bear and comparable to that of other marine mammals.[10] The bears farther north tend to stay longer with their young, with weather conditions and age of the female affect this time as well. Sexual maturity is reached at 3-4 years. Adult polar bears are known to live over 30 years in captivity with average around 25. In the wild this is likely much shorter.

Polar bears do not hibernate, though lactating females go into dormancy during denning. The female can control urea cycling so she can endure a long fast during this time; they often go without eating for a period of nine months and rely on stored body fat (also known as blubber) to keep themselves and their cubs alive. Once the cubs mature they go their separate ways.

The 2004 National Geographic study found no cases of cubs being born as triplets, a common event in the 1970s, and that only one in twenty cubs were weaned at eighteen months, as opposed to half of cubs three decades earlier.


In Alaska, the United States Geological Survey reports that 42 percent of cubs now reach 12 months of age, down from 65 percent 15 years ago.[27] In other words, less than two of every three cubs that survived 15 years ago are now making it past their first year.


Conservation status

The population of 20,000-25,000 polar bears has been shrinking. On the west coast of Hudson Bay in Canada, for example, there were an estimated 1200 polar bears in 1987, and 950 in 2007.


In February 2005 the environmental group, Center for Biological Diversity, with support from American senator Joe Lieberman, petitioned the United States Fish and Wildlife Service (FWS), part of the Department of the Interior to use the Endangered Species Act and list the bears as a threatened species.


Under United States law the FWS was required to respond to the petition within 90 days, but in October 2005 after no reply had be received the Center for Biological Diversity threatened to sue the United States Government. On 14 December 2006 the Center for Biological Diversity along with Greenpeace and the Natural Resources Defense Council filed a lawsuit in California.

On December 27, 2006, the United States Department of the Interior in agreement with the three groups proposed that polar bears be added to the endangered species list, the first change of this type to be attributed to global warming. It will take up to a year to make the final determination.

The World Conservation Union had already given polar bears threatened status in May 2006.


Threats natural and unnatural

The most immediate and topically recognized threat to the polar bear is the drastic changes taking place in their natural habitat, which is literally melting away due to global warming. The United States Geological Survey, for example, in November 2006, stated that the loss of sea ice in the Alaskan portion of the Beaufort Sea has lead to a higher death rate for polar bear cubs.

The Harvard University Gazette said:

* A 1999 study of polar bears on Hudson Bay showed that rising temperatures are thinning the pack ice from which the bears hunt, driving them to shore weeks before they've caught enough food to get them through hibernation.

The BBC reported:

* Climate change is threatening polar bears with starvation by shortening their hunting season, according to a study by scientists from the Canadian Wildlife Service.

There is also some concern over pollution in addition to the normal natural problems the bears might face. Reduced cub survival has been reported in connection with PCBs, as well as reports of organochlorines affecting the endocrine system and immune systems with lower immunoglobulin G seen with increasing PCB levels. The lipophilic PCBs are considered a serious threat to marine mammals generally and to their food web, quickly concentrating into fat and blubber. These and related compounds are known in mammals (including humans) to cause such things as abortion, still births, alteration of the menstrual cycle, poor growth and survival of young, carcinogenicity, immunotoxicity, and even outright lethality.

Other classes of organohalogens have been found in polar bears, such as PCDDs, PCDFs, TCPMe and TCPMeOH. Hermaphroditic polar bears[1] have now been observed in less pristine areas. While some countries now ban some of these substances, they are still produced in others, and still end up all over the entire planet including the formerly pristine arctic. Even after the use of these chemicals is stopped, they continue to accumulate up the food chain, including in marine mammals and humans, for some time to come.

The bears sometimes have problems with various skin diseases with dermatitis caused sometimes by mites or other parasites. The bears are especially susceptible to Trichinella, a parasitic roundworm they contract by eating infected seals. Sometimes excess heavy metals have been observed, as well as ethylene glycol (antifreeze) poisoning. Bears exposed to oil and petroleum products lose the insulative integrity of their coats, forcing metabolic rates to dramatically increase to maintain body heat in their challenging environment. Bacterial Leptospirosis, rabies and morbillivirus have been recorded. Interestingly, the bears are thought by some to be more resistant than other carnivores to viral disease. The pollutant effect on the bears' immune systems, however, may end up decreasing their ability to cope with the naturally present immunological threats it encounters, and in such a challenging habitat even minor weaknesses can lead to serious problems and quick death.


Entertainment and commerce

Polar bears have been made both controversial and famous for their distinctive white fur and their habitat. Companies like Coca-Cola, Polar Beverages, Nelvana, Bundaberg Rum and Good Humor-Breyers have used images of this bear in logos. The first has consistently displayed the bears as thriving near penguins, though the animals naturally live in opposite hemispheres. The Canadian 2-dollar coin features the image of a polar bear. The panserbjørne of the fantasy trilogy His Dark Materials are polar bears with human-level intelligence.

The TV series Lost has featured polar bears on a mysterious tropical island.

Trivia

* On April 25, 2006, the first and only grizzly-polar bear hybrid found in the wild was killed by a sport hunter at Banks Island, Northwest Territories, Canada. An RNA test by Wildlife Genetics International in British Columbia confirmed it was a hybrid, with a polar bear mother and a grizzly bear father.

* In February 2004, two polar bears in the Singapore Zoo turned green due to algae growth. A zoo spokesman said that the algae had formed as a result of Singapore's hot and humid conditions. The bears were washed in a peroxide blonde solution to restore their expected colour. A similar algae grew in the hair of three polar bears at San Diego Zoo in the summer of 1980. They were cured by washing the algae away in a salt solution. This is very common in all zoos in warm areas.

* In July 2005, during an extremely hot and humid summer in Chicago, several polar bears in the Brookfield Zoo turned green as a result of algae growing in their hollow guard hair tubes. The staff let the harmless algae run its course, and did not subject the bears to chlorine or bleach treatment.

* In April 2003, the American submarine Connecticut (SSN 22) poked its sail and rudder through an area of polar ice between Alaska and the North Pole. A large (700-800 lb) polar bear was seen approaching the sub and loitering for about 40 minutes around the subs rear rudder. It took a bite out of the rudder and, finding it inedible, stayed around the area of broken ice near the rudder for a time, apparently thinking a seal might use it as an air hole. The bear finally left when he heard the noise of an approaching helicopter. Photos of the polar bear at the submarines rudder were taken from the periscope camera and distributed to the media.

* In December 2006 the reported world's oldest polar bear turned 40 years old. Debbie the Polar Bear lives at the Assiniboine Park Zoo in Winnipeg, Manitoba.

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