Alaska's salmon-feasting bears face off in biggest Fat Bear Week ever

A mother bear and two cubs in Brooks River, where brown bears living in Katmai National Park and Preserve are entered into a tournament celebrating bears that have put on pounds to survive the winter. C. Loberg/NPS hide caption

The brown bears in Katmai National Park and Preserve in Alaska, famous for embiggening themselves by feasting on salmon in the park's scenic Brooks River, are ready for their annual closeup. The 2026 Fat Bear Week bracket came out on Friday, kicking off a competition to determine which bear has worked hardest to pack on pounds for hibernation.

Short Wave This Fat Bear Week, take a look at the scientific reasons bears need to bulk up Officials say fans should look out for signs of a generational shift, reflecting the vitality of Katmai's ecosystem. And this year's bracket features 16 bears, up from 12 in recent years.

"There are more cubs at Brooks Camp this year than have been seen in a long time," Park Superintendent Mark Sturm said in a news release.

"A new generation of fat bears is taking shape, and they're off to a strong start," Sturm added, saying his team is eager to see how the young bears develop and fit in.

New contenders this year include Bear 89, a male known as "Backpack." His nickname originated after an injury he had as a cub forced him to ride around on his mother's back, according to the park's website. Another male competitor is 151 Walker, one of the most dominant bears on the river.

This year's single-elimination tournament begins on Tuesday, Sept. 22, when public voting starts. Voting pauses over the weekend, before a new champion is crowned on Sept. 29.

Animals Exclusive: Meet the inaugural winner of Fat Marmot Week Viewers can follow the Katmai bears' exploits on webcams from Brooks River on Explore.org. The brown bears and cubs fill TV screens and computer monitors with fishing, eating and inter-ursine drama, giving humans a much-needed break from thinking about AI, midterm elections and the economy.

Instead, they can ponder the chances that last year's winner, the immense Bear 32 nicknamed "Chunk," might again be dubbed the fattest bear of them all. Weighing in at over 1,200 pounds, Chunk won over voters last year by chowing down despite suffering a broken jaw and even finding time to play with younger bears. It was a redemption story of sorts, coming a year after Chunk was villainized by some after killing a cub belonging to Grazer, the 2024 champion.

Individual bears have differing priorities, Katmai National Park Ranger Sarah Bruce said in an online chat unveiling the bracket. For example, she noted that many single adult females must help their cubs get enough calories.

"When you're voting, consider the challenges of a bear's life," Bruce said. "Trust your gut and go with whatever you think the fattest bear is."

This has been a record-setting year for cubs, said former Katmai ranger Mike Fitz, resident naturalist at webcam company Explore.org. He says 37 cubs were counted at Brooks River. Several cubs are included with their mothers in this year's bracket, such as Bear 806, which adopted an older cub along with raising her own cub from this spring. Bruce also noted the importance of resilience, describing how Bear 909 has prepared for hibernation after losing both of her cubs this year.

Before-and-after photos of the bears highlight the stunning transformation they undergo each year, after emerging gaunt and bony in the spring and bulking up from as little as 600 pounds for an adult male in the summer up to more than 1,000 pounds in the fall.

Animals Fat Bear Week delayed after a large bear kills a rival bear The bears endure a condition called hyperphagia, feeding a relentless hunger so they can pack on fat they'll need to survive the coming winter. The park uses Fat Bear Week to teach the public and students about brown bears, sockeye salmon and their ecosystem. Some 2,200 bears are estimated to live in Katmai National Park and Preserve's 4.2 million acres.

Interest in Fat Bear Week, which began in 2014, is international: For last year's contest, people cast more than 1.7 million votes from more than 100 countries, according to the park.

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