Winter brings a season of rest, relaxation and staying at home, for humans and bears alike. But for bear researchers, winter is the perfect time to get out, explore and learn about hibernation patterns.
What makes a good bear den?
Every winter, researchers track where bears make their dens and may even enter them to do a health checkup on cubs. Even though bears have been around for millions of years, there’s still a lot to learn about bear dens.
“It’s a big question in the bear biology community … what makes a good bear den?” said Dr. Rae Wynn-Grant, Mutual of Omaha’s Wild Kingdom Protecting the Wild co-host and bear expert.
What researchers have found is bears make their dens based on their perception of being safe from threats and having resources, but they don’t return to the same den year after year. Dens can be deep in the wilderness or close to civilization, like near a ski resort.
“I met a mama bear in the Asheville, North Carolina, area who made her winter den with her cubs right under a highway,” Dr. Rae said. “It’s in the mountains, but hers was at the base of this tree under an overpass. For whatever reason she chose that as a safe place to give birth to her cubs.”
Researching bear dens helps conservationists better understand bear behavior so we, as humans, know how to best protect the species. Some female bears may choose a den closer to activity because it’s further away from aggressive males.
“Conservation isn’t always creating protective areas. Sometimes it’s really understanding the nuances and complexities through animal behavior,” Dr. Rae said.
Hibernating bears on Mutual of Omaha’s Wild Kingdom Protecting the Wild
In the Protecting the Wild episode, “Into the Bear’s Den,” Dr. Rae checked on three bear cubs nestled in the New Hampshire woods.
“The experience was magical and technical simultaneously,” Dr. Rae said. “Entering a black bear hibernation den is serious work, with consequences for both the scientists and the bears, so all protocols have to be strictly followed.”
Dr. Rae worked with the New Hampshire Fish and Game Department to perform a checkup on the cubs after carefully administering a sedative to mama bear, because even though she’s hibernating, she’s not fully asleep.
“Because they have several newborn bear cubs in the den with them, they aren’t asleep, but rather have a slower metabolism and breathing rate,” Dr. Rae said. “This means they are awake and can abandon the den, attack approaching humans or simply feel extreme stress if they observe humans approaching.”
So, be sure to leave the bear dens to the professionals! To get an inside look at a bear den from the safety of your home, watch the episode.
But do all bears hibernate?
As scientists are learning more about bears, we can also educate ourselves on their habits. A fun way to start? By discovering that not all bears hibernate in the winter!
“Hibernation is fascinating, but something that’s necessary only when food resources are low,” Dr. Rae said.
Even among species that hibernate, such as black and brown bears, not all these bears will hibernate during the winter. Bears in northern Minnesota will find a den, while those in Florida don’t hibernate at all.
“I live in a part of California that has black bears that don’t hibernate,” Dr. Rae said. “But in other parts of California, food resources are gone in the winter.”
Bears instinctually slow their metabolism down to hibernate when they know food is scarce during the winter so they can survive to the spring.
In Association of Zoos and Aquariums accredited facilities, many bears don’t hibernate because they’re provided food, eliminating the need to slow their metabolism.
“However, some facilities intend to reintroduce the animals back into the wild, and these facilities will create scenarios for the bears to hibernate,” Dr. Rae said.
How to be safe in hibernation season
Hibernation is a very vulnerable time for black bears, especially mothers and cubs. Their biggest threat is den disturbance by humans. This can be done inadvertently by hikers, cross-country skiers and snow mobiles. Den disturbance can cause den abandonment, which is when the mother bear leaves the den and can’t take her less mobile cubs with her.
So, if you’re planning on visiting an area that’s home to bears, do your research. Stay on trails and be vigilant. Check out the state’s department of wildlife to learn more.
“Actions you take to be a responsible camper during the summer should be the same during the wintertime,” Dr. Rae said. “Animals that are out and about in the winter might be extra hungry. They have an ecology that allows them to survive the winter, but they’re definitely still looking for food resources.” So, keep your distance!
Learn how to safely prepare your visit during hibernation season.
Plus, check out these tips for enjoying wildlife in the winter.
