"I'm going to speak my mind because I have nothing to lose."--S.I. Hayakawa

Wednesday, November 23, 2011

The Polar Bear Journals, Ch. 7, Hold the Mustard on that Dog

((I suppose talking about polar bears fasting for several months is appropriate on Thanksgiving Day.) 

“I never made a mistake in my life.

 I thought I did once, but I was wrong.”

—Lucy van Pelt—Peanuts character

by Charles Schultz



Unlike crabby Lucy, I admit the error of my ways when confronted with evidence of my mistakes.  So here it is:


I was wrong.


Whether by lack of information, incorrect assumptions, and/or failure to research, I was wrong about the effect climate change is having on polar bears.  I admit it.  I was wrong. 


That climates are changing is, I think, indisputable.  What’s causing it is the question.




When I first heard the ice pack in northern Alaska was melting at an alarming rate and threatening the habitat of polar bears, I figured the huge white bears could do what their cousins do—hunt caribou and moose calves, eat berries, dig for grubs, catch fish, chow down on vegetation.


Mike Goodyear set me straight.  He’s the 37-year-old executive director of the Churchill Northern Studies Centre and has been for 11 years.    He’s also a wildlife biologist who concentrated his studies on marine mammals of the Canadian north.  The Centre itself has been operating since 1976,  with scientists collecting data not just on bears, but all things northern.


Thus, Mike and other scientists have access to several decades of data collected in the Churchill area, all of which points inexorably to one conclusion:  the polar bears are threatened with starvation because the ice is melting sooner and forming later every year.


Sleeping on a frozen pond helps keep the bear cool.



Related to the great brown bears, such as the huge Kodiak bears of Alaska, polar bears evolved to exist in northern climes.    From the shapes of their heads and paws, small ears and sense of smell, to the thick white fur that covers their bodies, the bears are well suited for hunting and finding food on sea ice.



Two young males spar while the great white lump on the right wants no part of expending so much energy.



They are carnivores, existing solely on a diet of protein and fat.  Lots of protein and fat, like the 30 percent fat and 30 per cent protein found in the average ringed seal, their primary diet.  They might munch on berries and grass while onshore, but those things provide little in the way of nourishment. 


When melting ice drives the bears onshore in mid-summer in Churchill, their metabolism slows down, akin to the hibernation metabolism their land-dwelling cousins experience, yet the polar bears do not sleep as do the other bears.  Essentially, they fast while they are onshore. 




This year the ice went out in early July.  Looking at a satellite image on Nov. 19, I could see ice was forming and I suspect the bears are venturing onto it, finding food for the first time in almost five months.  The sows with cubs will follow, staying well away from the male bears.





“You can throw a hot dog to a polar bear and it will eat it,” said Mike.  But, he continued, it will cost the bear more energy to restart its metabolism and digest the hot dog than it gains from it. 



Sunset over the tundra at Churchill.  And maybe for the polar bears, too.
(to be continued)

No comments:

Post a Comment