Jim McMahon/MapMan®

For brown bears, bigger is better. A bear named Beadnose won this year’s Fat Bear Week competition at Katmai National Park in Alaska. From June to October, bears gain as much weight as possible to get ready to hibernate. Beadnose nearly doubled her weight in three months. She now tips the scales at about 800 pounds.

“Beadnose’s transformation this summer was remarkable,” says park ranger Russ Taylor.

Voters in the contest agreed. For months, people from around the country watched on the park’s live bear cams as the animals splashed in a river and dove for salmon. Brown bears chow down on at least 30 salmon a day. Each fish has about as many calories as 15 cheeseburgers.

Brown bears also eat berries, plants, and just about anything else they can get their paws on. As they bulk up for winter, the bears can gain up to 6 pounds
of fat each day.

In October, park rangers posted before-and-after photos of the Katmai bears on social media. Then people voted for the one that appeared to have gained the most weight. Beadnose was the big winner. But fattening up isn’t about winning a contest.

“A bear that doesn’t get fat enough might not survive the winter,” says Taylor.

Beadnose and the other bears in the park have already begun hibernating. Between late October and early December, bears dig out their dens on a steep slope and settle in. For at least five months, they won’t eat, drink, or go to the bathroom. They’ll get all the nourishment they need from their body fat.

While in hibernation, Beadnose will lose about a third of her body weight. She’ll emerge from her den much lighter in the spring. Then, before long, she and the other bears will start fattening up all over again.