The grizzly bear population of Yellowstone National Park is just beginning to awaken from hibernation and as they emerge from their dens they are hungry to replenish the untold thousands of calories expended during their long winter’s nap.
On average a grizzly bear burns approximately 4,000 calories per day to sustain their vital functions during hibernation including maintaining body temperature and organ activity. Over the course of hibernation a grizzly bear can lose 25–40% of their overall body weight as they burn through fat reserves accumulated during hyperphagia (the feeding frenzy prior hibernation).
This grizzly bear was filmed on March 31st, 2025 in Yellowstone’s Upper Geyser Basin where it approached a herd of bison likely looking for an easy target to pack on the pounds after going many months without a fresh kill. The 20+ bison were more than enough body mass to intimidate the lone predatory grizzly and drive it away.
The video was clip was taken from the Old Faithful & Upper Geyser Basin Livestream Webcam which is made possible through a generous grant by partner Canon USA, Inc. There are 9 additional static webcams throughout the park including Mammoth Hot Springs, West Yellowstone Entrance Station, Mount Washburn, and Yellowstone Lake that refresh roughly every 30 seconds.
Yellowstone National Park Bear Safety Guidelines:
All of Yellowstone is bear country, from the trails in the park’s backcountry to the boardwalks and parking lots around Old Faithful. Your safety cannot be guaranteed, but you can play an active role in protecting yourself and the bears people come here to enjoy.
- Give bears space. Keep at least 100 yards (93 meters) from bears at all times and never approach a bear to take a photo.
- Carry bear spray and know how to use it. We recommend each person carry one can of bear spray in a readily accessible location like a quick-draw holster (not stowed away in your backpack).
- Hike in groups and make noise. Since 1970,91% of the people injured by bears in Yellowstone were hiking alone or with only one hiking partner. Only 9% of the people injured by bears were in groups of three or more people. While hiking on a trail, periodically yell “Hey bear!” to alert bears of your presence. Learn more about backcountry safety.
- Respect closures. Observe all closures and restrictions in active bear management areas.
- Never feed bears. Bears that become dependent on human food may become aggressive toward people and will be killed.
- Stay with your stuff. Do not leave packs or bags containing food unattended, even for a few minutes, as bears learn new food sources quickly.
- If a bear approaches or touches your car, honk your horn and drive away. We want to discourage this behavior for the bears’ safety and yours.
- Help us spread the word! Share posters from our “A Bear Doesn’t Care” campaign.
If you’re involved in a conflict with a bear, regardless of how minor, contact us or report it to a park ranger as soon as possible. If cell service is available, dial 911. The lives of other people, and the bear, may depend on it.