Fat Bear Week Returns: Katmai’s bears prep for winter hibernation

For brown bears along Brooks River in Katmai National Park, making it through the winter is a matter of survival of the fattest. And the bears in this area are some of the largest in the world, according to explore.org, the organization that hosts the competition. The abundance of salmon in Brooks River provide a rich and nutritious food source for the bears. 

Katmai and explore.org partner each year to celebrate the chonkiest bears in a friendly “Fat Bear Week” competition. 

This is a single elimination tournament, according to the website. For each match-up, participants can vote for the bear they believe best exemplifies fatness and success in brown bears. The bear with the most votes advances to the next round. Only one will be crowned Fat Bear Week champion.

Preparing for Hibernation

In order to prepare for a period of winter hibernation, bears enter a state of hyperphagia during the autumn months. During this time, bears spend almost all of their time eating and seeking food, and they can put on up to four pounds a day. 

The bears all do their best to get as fat as possible before the winter, when food is scarce. But some face more challenges than others. Mother bears need to eat as well as feed and protect their cubs. Older bears might have more difficulty finding enough food when in competition with younger, stronger bears. 

During hibernation, bears do not eat or drink and will lose one-third of their body weight, according to explore.org. Their winter survival depends on gaining enough weight to survive a long winter in their den.

A Fat Bear Delay

This year, a brutal bear-against-bear attack that left bear 402 dead delayed the announcement of the Fat Bear Week Bracket. Read more about the story.