Climate change has silver lining for grizzlies

Posted By News On October 28, 2013 - 5:00pm

Global warming and forest disturbances may have a silver lining for threatened species of grizzly bears in Alberta, Canada.

In a 10-year study that monitored 112 bears in Alberta's Rocky Mountain region, University of Alberta biologist Scott Nielsen and his colleagues found that warmer temperatures and easier access to food associated with forest disturbances helped the grizzlies to build more body fat, known to increase the chances of successful reproduction for mothers.

The resulting 'silver spoon effect' shows that bears born into these favourable conditions have a head-start in life, said Nielsen, an assistant professor in the U of A Department of Renewable Resources.

"Understanding variations in body size helps us understand what limits grizzly populations," Nielsen said. "We get clues about the environments that most suit grizzlies by examining basic health measures such as body size. A simple rule is, the fatter the bear, the better. Certain environments promote fatter bears.

The findings, published in BMC Ecology, may help influence forest harvest designs to enhance habitat for the Alberta grizzly, which is classed by the Alberta government as a threatened species. Currently there are only about 750 of the bears in the province, half of them adults.

In years when warmer temperatures and less late winter snow brought on earlier spring conditions, the body size of bears as adults was larger. Smaller bears were found in colder and less productive environments or years that were abnormally cool.

"We hypothesize that warmer temperatures in this ecosystem, especially during late winter and spring, may not be such a bad thing for grizzlies," Nielsen said, noting that historically the range for the bears once extended as far south as Mexico and persists today even in the deserts of Mongolia. "That suggests the species won't likely be limited by rising temperatures which would lengthen the growing season and the time needed to fatten prior to hibernation."

As well, bears that used disturbed forest habitats containing a wide variety of stand ages were healthier, Nielsen said.

"The diversity of stand ages in the landscape has a positive influence on body condition because bears are better able to access a wide range of food sources."

Global warming?

Whenever I pose this question, I never receive a response. I hope somebody will eventually have the courage to respond to this question. Which is it? Are you afraid of losing your funding and having to get a real job?

No, I'm not afraid of a "real" job. I have one. I'm a business owner. So what? Do you have a point to make with the websites you offered? They lead me to believe that you reject the overwhelming science supporting human-caused climate change. The hurdle you can't get over... The world's respected scientific institutions and the many studies that have been completed don't agree with you. The pushback is coming mostly from the vested interests like The Heartland Institute and their Koch brothers sponsors.

I retract my earlier annoymous comments and apologise.

I checked a history of temperatures in Banff for the last 30 years and temperatures there have remained absolutely constant with no increase.

This story is nonsense and the research is highly suspect. Whoever is funding this needs to answer to this.

Please reread story. It didn't say temperatures had increased. They simply found that bears in warmer environments, and those enjoying more favorable weather cycles are larger and fatter. Actually, kind of a no brainer. But they do infer from their findings that some temperature increase would be good for the bears.
More interesting to me was the finding that a mosaic of logged areas is good for bears. Again, a no brainer, but it will come as a surprise to the sort of enviros who demand humans keep their hands off.
By the way Science Codex, your Captcha gimmick is unreadable and the audio sounds like cats being killed. I had to go through at least a dozen attempts to post. Totally useless.

That is very interesting research.

With such an "educated" society, we assuredly have nothing to worry about.

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