Why are black bears hibernating less?

What will the lives of bears look like in the face of climate change? We know that melting sea ice for polar bears is a serious threat, but what about bears in our own state?

The New York Times released an article this month by Kendra Pierre-Louis that made us rethink the sleepy bear image we grew up knowing. As children we are introduced to the phenomenon of hibernation through foldable readers, sing-along-songs, cartoons, and film. But children authors may need to start rewriting the story that we have all come to know and love.

Increased spring and summer temperatures coupled with earlier spring snowmelt (pictured) is changing the natural biological rhythms of black bears. This phenomenon also leads to increased fire seasons, fire size, and severity.

A. L. Westerling, H. G. Hidalgo, D. R. Cayan, T. W. Swetnam. 2006. Warming and Earlier Spring Increase Western U.S. Forest Wildfire Activity. Science 313:940-943.

Increased temperatures and warmer winters may wake bears early or cause them not to go into hibernation at all. This is because environmental factors such as decrease in food supply and colder temperatures are cues to bears that it is time to go into torpor. Without these cues from their environment, they continue to forage in suitable habitat where grasses, pine nuts, and wild fruits are available. Warmer weather reveals food sources that are normally covered in snow pack, and this expansion in food supply may be another reason that the bears aren’t succumbing to their deep slumber routines.

Climate change doesn’t always lead to an increase in delectable forage. Extreme and variable levels precipitation can drastically decrease food sources during years of drought. This happened 3 years ago in the state of Nevada. Depleted food sources means starving and desperate bears, and the state wildlife agency saw a dramatic increase in human-wildlife conflicts that year.

As bears desperately tried to find food, they took to the streets in Tahoe – damaging property and entering homes. It’s a tough situation for both agencies, the public, and advocacy groups. No one who loves and appreciates wild things wants to see bears get put down – they are part of America’s heritage. In a juggle between public safety and wildlife management, there are tough calls that must be made and problem bears are euthanized.

We can do our part to protect bears by utilizing bear-proof garbage cans, removing attractants in vehicles, and securing our homes. A tourist location such as Tahoe adds complexity to the bear problem. Folks come from all over the world to visit the lake, book vacation rentals, hike the trails, and may not be versed on bear safety. It’s important to never leave food unattended at day-sites, campgrounds, and in your vehicle.

As their food supply is altered by climate change, it is important to play our part to protect bears when vacationing or in our own local community. Limit bears access to food sources in your own backyard and take certain precautions when you’re out on the trail. Also, spread the word that responsible wildlife watchers don’t feed wildlife!

Korinna Domingo

Leave a Reply Text

Your email address will not be published. Required fields are marked *