The Hoax of the Hibernating Bear
Here at Bear Smart HQ in beautiful Whistler, BC all of our local bears are sleeping off a high calorie diet in their cozy little dens scattered around the mountainsides. Most bears in northern climates, in fact, are now into their hibernation cycle with the exception of most polar bears (except moms with newborns) and blacks and grizzlies who have found unnatural food sources.
Many bear dens are excavated into hillsides or into the hollow base of a tree, stump, or rock cavity and provide a safe place for bears to knock out, catch a few zzz’s, and – for those lucky expectant mothers – pop out a couple cubs.
During hibernation bears survive without eating by living off their fat reserves and by going into a state of dormancy; metabolism slows drastically, body temps drop by 3-7 degree Celsius, and hearts beat roughly 8-12 times per minute. It’s quite remarkable, actually.
The hoax? We used to think that when bears are hibernating they went into a coma-like state slipping into an unwakeable sleep. And while bears aren’t practicing yoga or doing many activities in the den, they are as active as anyone could be in such a small living space with a drastically slowed physiology and no internet. They even dream of tasty ants, plants, and alpine vistas.
Six Interesting Things Bears Do In the Den:
1. Shift Positions
Wouldn’t you? I can’t imagine the physio my neck would need if I slept under a tree for 4-6 months without rolling in and out of my favorite sleeping positions.
2. Scratch, Stretch, and Scratch Some More
Obviously connected to the shifting positions, popular den activity includes a good belly scratch from time-to-time as well as some mild back bends and forward rounding.
3. They Don’t Defecate
Something bears rarely do while in the den is to defecate or urinate; a relief for everyone involved in den life, I’m sure.
While humans would die from the build-up of urea from not urinating all winter, a hibernating bear has the unique ability to recycle urea to create new proteins – one of the secrets of den life.
5. Giving Birth and Keeping the Cubs in Line
Born smaller than grown squirrels, bear cubs are birthed in the den. Mom even goes through intense labor. No, they don’t just fall out and, unless they get constant mothering, they squeal like tiny rats. Her body and hot breath keep young cubs warm and mom sleeps less deeply to ensure crawling cubs don’t venture too far away from her nipples (of which she has six!). She also helps them to urinate and defecate while simultaneously keeping the den clean – a process that is, well, the mark of a very committed mother. Watch a video of Lily caring for her newborn cub, Hope.
6. Yawn, Adjust the Bedding, and Go Back to Sleep
Spring is coming.
To watch first-hand the day-to-day of den life, follow the bears of the North American Bear Center live in their dens.
Learn more about hibernation. Watch the highlights from den cams.