Grizzly Bears Benefiting from Climate Change

By: By Laura Dattaro
Published: October 29, 2013

A female grizzly bear in Yellowstone National Park. A study of the bears in Alberta, Canada has shown that warming temperatures may be good for the bears' health and reproduction. (Karen Bleier/AFP/Getty Images)

Climate change may be making some grizzly bears fatter — and that’s apparently a good thing.

“A simple rule is, the fatter the bear, the better,” Scott Nielsen, a biologist at the University of Alberta, said in a press release. “Certain environments promote fatter bears.”

Those fat-promoting locales may be more prevalent in a warming world. For 10 years, Nielsen led a team that followed 112 bears in the Rocky Mountain region of Alberta, Canada, finding that in years when spring arrived earlier due to warmer temperatures, adult bears had larger bodies and found food more easily. The grizzlies also developed more body fat, which increases the chances that females will successfully reproduce, according to the release.

(MORE: Seven Mostly Awful Climate Change Winners)

The Alberta grizzly is classified as a threatened species by the Alberta government, with about 750 bears living in the province. Only half of those are adults, which can reach up to 800 pounds, according to National Geographic. Though grizzlies tend now to be associated with northern environments, they used to be found as far south as Mexico, and some populations still exist in the Mongolian desert.

“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. “That suggests that species won’t likely be limited by rising temperatures, which would lengthen the growing season and the time needed to fatten prior to hibernation.”

Nielsen's study did not examine hibernation habits of the bears, but, according to Nielsen, warmer weather may not pose a problem for hibernating.

"Grizzly bears just south of Alberta in Montana and probably in the very south ends of Alberta are now denning on the prairies where there is very little snow, so that may not be as limiting as some folks think," Nielsen told "Denning is a response to food shortage, not snow."

The study’s findings are published last month in the journal BMC Ecology.


Featured Blogs

California Drought/Polar Vortex Jet Stream Pattern Linked to Global Warming

By Dr. Jeff Masters
April 16, 2014

From November 2013 - January 2014, a remarkably extreme jet stream pattern set up over North America, bringing the infamous "Polar Vortex" of cold air to the Midwest and Eastern U.S., and a "Ridiculously Resilient Ridge" of high pressure over California, which brought the worst winter drought conditions ever recorded to that state. A new study by Utah State scientist S.-Y. Simon Wang found that this jet stream pattern was the most extreme on record, and likely could not have grown so extreme without the influence of human-caused global warming.

March 2014 Global Weather Extremes Summary

By Christopher C. Burt
April 15, 2014

March featured a number of anomalous extreme weather events such as the floods in portions of Egypt and New Zealand, a freak hailstorm in Asmara, Eritrea, record warmth in much of Europe, severe cold and snow in the eastern half of the U.S. and heavy rainfall in the Pacific Northwest that culminated in a deadly landslide in Washington. Preliminary data from NASA indicates that globally (land-ocean temperature index), it was the 4th warmest March on record (since 1880).

Polar Vortex, Global Warming, and Cold Weather

By Stu Ostro
January 10, 2014

Some thoughts about the recent viral meme(s).

Just in time for the Holidays! Wundermap has a new layer: Precip Start Time!

By Shaun Tanner
December 23, 2013

The Weather Underground elves have been hard at work developing a brand new layer for the WunderMap and they made their deadline. Enjoy the newest addition to the WunderMap. Also remember to give us your feedback!

What the 5th IPCC Assessment Doesn't Include

By Angela Fritz
September 27, 2013

Melting permafrost has the potential to release an additional 1.5 trillion tons of carbon into the atmosphere, and could increase our global average temperature by 1.5°F in addition to our day-to-day human emissions. However, this effect is not included in the IPCC report issued Friday morning, which means the estimates of how Earth's climate will change are likely on the conservative side.

Astronomical VS. Meteorological Winter

By Tom Niziol
March 1, 2013