Are Polar Bears Victims of the New Cold War?

Climate change may be affecting the bears' habitat.

A polar bear takes a dip. [CREDIT: RACHELE COOPER]
By | Posted February 5, 2007
Posted in: Environment, Featured
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A male polar bear is stalking his prey. Suddenly, he makes a beeline for his target. Punching a massive paw through the victims’ snowy den, he gives his prey, a mother and two offspring, little chance. The bear bites down on her neck. The ensuing struggle collapses the den, suffocating the cubs.

But the victims are not ringed or bearded seals, typical polar bear food. They are also polar bears, victims of a perplexing act of cannibalism that researchers fear may become increasingly common as global warming puts more pressure on the Arctic’s largest predator.

This 2004 incident, reported by Steven Amstrup of the U.S. Geological Survey’s Alaska Science Center, was the first report of polar bear cannibalism in two decades of study in the Beaufort Sea area of northern Alaska, and in 30 years of studies in northwestern Canada. Since then, Amstrup has documented two additional cases.

“We can’t say the observations we made are definitely related, but they are consistent with changes seen in the Arctic,” said Amstrup. Other experts agree that cannibalism could be a harbinger of a decline in the polar bear population.

“We’ve never seen evidence of a male footprint in a female’s den,” said environmentalist Deborah Williams, who explained that females usually build dens in secluded areas away from male polar bears. Williams is president of Alaska Conservation Solutions, an environmental organization devoted to fighting global warming.

Polar bear populations are decreasing in the southern Beaufort Sea region of Alaska and the western and southern Hudson Bay in Canada. As a result, the U.S. Fish and Wildlife Service accepted a proposal last December to designate polar bears as a threatened species under the Endangered Species Act. Over the next year the organization will evaluate scientific data about polar bears before making a decision.

Some prominent researchers suspect that changes in the climate are a leading threat to polar bear survival. Polar bears are especially vulnerable to rising Arctic temperatures because they hunt, mate and usually make their dens on sea ice. “There is no evidence they can survive on land without sea ice,” Williams said.

Polar bears move inland and live off stored body fat during summer months when sea ice levels are lowest. In the fall, when the ice returns, they venture off land to resume hunting for seals.

With warmer temperatures, the bears must wait longer for the ice to return. Researchers think that’s a key reason why they’re seeing more evidence of polar bear starvation and cannibalism, and why fewer cubs are surviving their first year than in the past.

Arctic sea ice has declined eight percent per decade since 1978, with a record low in 2005, according to satellite data collected by the federally funded National Snow and Ice Data Center. “Ultimately as the sea ice goes, so go polar bears,” Amstrup said.

There is a “greater cumulative body of evidence that polar bears are being affected,” said Amstrup, adding when “one year the polar bears are in prime condition and the next thing you see them dead on sea ice – it gets your attention.”

Autopsies show the bears are starving. The two bears Amstrup found in his 2006 Beaufort Sea study had no fat in their bone marrow, “a clear indication of death due to starvation,” said Williams. He said it was “the very first time scientists observed and documented polar bear starvation.”

Amstrup’s research also documented that polar bears are having smaller litters. He found that from 1990 to 2006 fewer cubs were reaching six months, compared to cubs born between 1976 and 1989.

The July issue of the journal Polar Biology reported four dead polar bears floating in the open waters of the Beaufort Sea in 2004 and attributed the deaths to drowning. But, not everyone is convinced by the data coming in.

“I’m going to write a letter to the World Wildlife Fund to ask who did an autopsy that found polar bears drowned,” said Fred Goldberg, an authority on polar history and exploration at the Royal Institute of Technology in Stockholm, Sweden.

Aerial surveys of the area between 1987 and 2003 found no evidence of polar bears drowning. Goldberg also stated that since the bears were protected from hunting in 1973, “there have never been so many polar bears.”

Mitchell Taylor, a polar bear researcher for the Canadian province of Nunavut, where many natives hunt polar bears legally, agrees and submitted a petition to the U.S. Fish and Wildlife Service opposing listing polar bears as threatened. He stated that only two populations of bears are decreasing because of climate change and “it’s not clear how polar bears…will be impacted.” Along the Davis Strait in Nunavit, Taylor said he found fat bears “pigging out on blueberries” and “catching seals in open water.”

In fact, the decline in polar bears has not been uniform across the arctic; the overall population has increased since the 1970’s, when most hunting was banned by treaty. More recent trends, however, have been troubling. Of the 19 separate polar populations, five are declining, two are increasing, five are stable, and there is insufficient data for seven more, according to the Polar Bear Specialist Group, a team of scientists dedicated to preserving the bears.

Andrew Derocher, a polar bear researcher and biology professor at the University of Alberta, led a study that found no evidence that polar bears can make the transition to become a land predator. They try to hunt in open water, but do not appear successful. “It is prudent to act sooner rather than later,” since large carnivores are not easy to conserve, he said.

Some, however, see the general rise in polar bear population and scoff at the possibility of regulation. “The law doesn’t say to look at any possible future threat. It says look at the data…if it’s not endangered then it’s not endangered,” said H. Sterling Burnett, a senior fellow from the National Center for Policy Analysis, a non-profit organization that promotes private alternatives to government regulation, who has written about the polar bear issue.

What counts, he said, is the number of polar bears that exist right now, not some possible decrease in the future. He noted the overall polar bear population has rebounded from about 10,000 to 20,000 and asserted that warm temperatures in the 1930s were similar to current conditions, yet polar bears survived then.

As for the reports of cannibalism, he said, “We can’t say we know it is a new phenomenon” because researchers do not have good data from earlier decades.

Burnett’s statement “contains a grain of truth to deceive the population” said Kassie Siegel of the Center of Biological Diversity who is the lead author of the petition to designate polar bears as threatened. As for the warm spell in the 1930s, Amstrup said that temperatures weren’t as warm or as uniform across the Arctic, adding that there’s no evidence that there were large decreases in sea ice, as there is now.

In the overall picture, said Williams, the Alaska activist, “polar bears are just one reason of literally thousands of reasons we must reduce greenhouse gas emissions. They are the tip of the iceberg.”

When this was originally published, the paragraphs introducing Goldberg were transposed.

Posted in: Environment, Featured

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  1. One thing that should have been done ages ago, but I have still not seen suggested, is stop running ice breakers all over the arctic.

    Even David Suzuki runs eco tour ice breakers to the North Pole and then is suprised there is open water there in Summer not noticing that there is also open water behind his boat.

    Running ice breakers through the polar ice cap has got to be having a profound effect on the polar bear environment. When you want to get rid of ice on your driveway, you break it off in parts. The ice breakers are doing the same thing to the polar cap. If we want truly protect the arctic, we need to stop breaking up the ice that is so crucial to the habitat.

    Bill, February 5, 2007 at 11:14 am
  2. This really brings home the problem, we need to do something to protect these valuable animals!

    Clare Norwe, February 5, 2007 at 12:03 pm
  3. “valuable animals”?
    Valued for what exactly?
    Your Fur coats?
    Coke commercials?

    Dave, February 5, 2007 at 3:31 pm
  4. Stop running icebreakers all over the arctic??? How do you think we’re getting all of this “conclusive data”? Former Coastie (Coastguardsman) here, I can vouch that breakers aren’t doing bupkus to sea ice since it re-freezes in hours(duh)pressure ridges and pinches bust up more ice than breakers. I thought people that read these articles were informed…Also, the polar bears I’ve seen looked pretty fat to me. Oh yeah, they were all very much ALIVE.

    Grant, February 5, 2007 at 5:11 pm
  5. The data, collected by the Canadian Government’s Biologists-says that Canada, which allows Polar Bear hunting has a healthier (growing-the Polar Bear population has doubled over the past 25 years-see Dr. Taylor’s report) Polar Bear population than does the U.S. which has made Polar Bear hunting illegal. The Marine Mammal Protection Act-in fact KILLS more bears than it saves-typical!

    TJ LOVELL, February 6, 2007 at 2:26 am
  6. cool tj. head up to alaska and kill the remaining bears. the population will be back up in no time.

    steve, February 8, 2007 at 9:27 pm
  7. I find it pretty interesting that some scientists are recommending that we only use the existing population data rather than looking at what changes are unfolding and their potential impact. As for Dr. Taylor’s work…I’m skeptical…populations with decreases are on west coast (i.e. Alaska) where impacts of climate change more pronounced but the east is starting to see some of the same effects. I find it hard to believe that a carnivore “pigging out on blueberries” will survive that way….not the same nutrients or fat content.

    whaleofatime, February 8, 2007 at 11:35 pm
  8. It is amazing that skeptics are berated for using tried-and-true scientific method, their credentials are always questioned, and invariably their funding sources are examined, but no one ever questions the legitimacy of the global warming alarmists. Climatology and Weather Sciences have historically been the red-headed step-child of science funding until Global Warming theory became a fad, now they have a cash-cow. No one seems to notice (or care) about the financial interest these people have. “Follow the money” and you’ll always get to the heart of the matter. Why is it that the alarmists always say “the debate is over” and refer to “consensus” when science is about constant revision of theory and is the antithesis of consensus? Lastly, why would anyone trust someone who lies to support their argument? >

    John Stettner, February 12, 2007 at 2:24 pm
  9. Just curious what “cash-cow” Stettner thinks the “global warming alarmists” would be cashing in on? “Follow the money” and you will find the Iraq war = OIL.

    And as far as “lies to support their argument,” we have only to look to our dear government to thank for that shining example.

    Look closely into any environmentalist’s motives for preserving the environment and i seriously doubt you will find much more money than what is truly needed to try to preserve the only planet we have.

    julie, February 25, 2007 at 1:28 pm
  10. It appears that Fred Goldberg does freelance work for the oil industry. As for Stettner, there aren’t aren’t many individuals who consider themselves serious thinkers who refer to consensus based scientific papers as “alarmist.” I imagine he consults a higher power for his analyses . . .

    In any regard, since I consider polar bears cuter than penguins, let’s ship the poor fellows to Antartica.

    mrunn, February 28, 2007 at 5:06 am
  11. Mitch Taylor, Fred Goldberg, Matt Cronin and others have become targets for marginalization because the cash cow of “global warming” is threatened by their research and science. Does that mean their work is less accurate? Hardly. These men not only live in the parts of the world where polar bears also live; they are individuals with character that they do not compromise in order to be viewed as “policially correct” or “popular.” Cronin’s article, “Polar Bears in PA,” may be read here: http://www.propertyrightsresearch.org/2006/articles11/polar_bears_in_pa.htm and should at least “break the ice” regarding the healthy polar bear population. Goldberg’s questioning of polar bear “drowning deaths” is valid. Taylor’s work is careful, meticulous and worthy of careful study. Before getting one’s exercise by jumping to conclusions or flying off the handle, read more about these three men and their work.

    Julie Kay Smithson, March 3, 2007 at 3:27 pm
  12. noo

    sara, March 4, 2007 at 10:10 pm
  13. the polar bear needs more info and so does the star fish.

    Brikaity maxred, March 7, 2007 at 9:41 am
  14. Follow the money indeed! The U.S. government funding of AGW research has increased from $190 million in the late 1990’s to over $4 billion in 2006 with a 15% increase scheduled in 2007. That money DOES NOT GO to AGW skeptics. In the academic community there is no penalty for being PRO-AGW, but any skepticism about the .054 of 1 percent of the atmosphere causing the environment to crash. Of all the CO2 emitted MAN is responsible for less than 4% and the cost of reducing this amount is tantamount to mass murder for the 3 billion people in the developing nations of the world.

    TJ LOVELL, March 30, 2007 at 2:18 am
  15. This helped a lot on my report for school thanks a bunch, but still that is sad with 4 dead bears floating in the sea.

    Mandy, February 1, 2008 at 10:48 am
  16. I would just like to say to please not act like you know everything on these animals and leave a completely ignorant comment, or report. I do not wish to insult anyone, but please don’t.
    Thank you

    Amafag, February 7, 2008 at 1:23 pm
  17. people who take this as a joke are plain ignorant n uneducated. these bears were put here for a reason so therefore we should value them.

    korntey, September 3, 2008 at 9:03 am
  18. Global Warming isn’t real, its called climate change. and i predict that after this global warming scare is over, we will be overrun by polar bears due to the Global Freezing that comes after the Global Warming.

    not my real name, November 8, 2009 at 3:31 pm
  19. Open your eyes America! It is happening, your greed for natural resources, your ignorance and your down right selfishness in doing absolutely nothing to mitigate the damage you do, is going to end very badly. Unfortunately not just for yourselves, but every other person and living creature on this planet. The science is there, and high time you people did the right thing. From a small person in a small country that cares !

    s20phs, February 14, 2013 at 6:38 pm
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