Fat Bear Week 2025 begins on September 23 at Katmai National Park and Preserve in Alaska. Fans from around the world cheer on the park’s brown bears in a March Madness-style bracket, voting for which bear should advance in each round. Last year, over one million votes were cast.

What is Fat Bear Week? (Unsplash) What is Fat Bear Week? (Unsplash) Why bears get so fat?

In late summer and early fall, bears enter hyperphagia, a time when they eat nonstop to prepare for hibernation. “They can’t feel full no matter how much they eat, so they just keep eating,” says Sarah Bruce, a park ranger at Katmai. For female bears, this weight gain is crucial for successful pregnancies. “A fertilized egg won’t even implant unless the mother is fat enough,” Bruce explains.

The Role of Salmon and Ecosystem Health

According to USA Today, Katmai’s brown bears depend on sockeye salmon, benefiting from one of the most sustainable salmon runs in the world, maintained with help from Indigenous knowledge and stewardship. The Brooks River’s salmon-rich waterfalls give bears plenty of food, allowing them to gain more weight than bears in other parts of the park. This year, an unusually high salmon abundance has allowed even older male bears to thrive.

Fat Bear Week 2025 contenders to watch

Fat Bear Week 2025 features returning favorites and new contenders. Fans will be watching 128 “Grazer” and 32 “Chunk”, among others. Grazer has won the event in 2023 and 2024, becoming the first female bear with a cub to take the crown. Several new bears, observed throughout the season, are already looking plump and ready for the competition.

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How to vote at Fat Bear Week 2025

Voting is open daily from noon to 9 p.m. ET on the Fat Bear Week website. Fans can also watch the bears live or in highlights on Explore.org, which streams footage from Brooks Falls. Fat Bear Week is a partnership between the National Parks, Explore.org, and the Katmai Conservancy.

A celebration of nature

While it’s a fun contest, Fat Bear Week also highlights the importance of healthy ecosystems. The bears’ bulking up is vital for survival, and the event reminds the world of the delicate balance between wildlife and nature.

Get ready to vote, cheer, and celebrate the fattest bears of Katmai National Park, because this year, survival of the fattest is the name of the game.

FAQs:1. What is Fat Bear Week 2025 and when does it take place?

Fat Bear Week 2025 is an annual event at Katmai National Park in Alaska, where fans vote for the park’s brown bears in a March Madness-style bracket. This year, it runs from September 23 to September 30, with daily voting from noon to 9 p.m. ET.

2. Which bears are competing in Fat Bear Week 2025?

The competition features a mix of returning favorites like 128 “Grazer” and 32 “Chunk”, as well as new contenders. The bears are judged on who has gained the most weight to prepare for hibernation, a vital part of their survival.

3. How can I watch or vote for Fat Bear Week 2025?

Fans can vote daily on the official Fat Bear Week website. You can also watch live streams and highlights of the bears at Brooks Falls on Explore.org. Fat Bear Week is a partnership between the National Parks, Explore.org, and the Katmai Conservancy.