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The 2020 Fat Bear Week winner Bear 747 (Courtesy of the National Park Service)

LOUISVILLE, Ky. (WDRB) -- Finally, it's Fat Bear Week — a most welcome week of healthy competition amongst brown bears.

Alaska's Katmai National Park and Preserve calls it "a celebration of success," a March Madness-style tournament, complete with a bracket, where you can vote on the heftiest brown bear in the bunch.

The bears are getting ready to retire to their dens for the winter, without food or drink until spring. Their fat reserves sustain them as their body weight dwindles by up to a third.

"For bears, fat equals success and survival," Lian Law, the visual information specialist for Katmai National Park said.  

Among this year's contenders: Chunk, one of the most dominant bears on Brooks River who exhibits some "enigmatic" behavior, and Holly, a medium-large adult female who was 2019's Fat Bear Week champion.

Voting takes place over several days on explore.org's website. You can also watch bears every day via LiveCam on the Brooks River in Katmai.

"Even thinking about putting together the bracket we had a really hard time narrowing it down to 12," Law said. "All of their stories are just such stories of success and important overall."

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The 2021 Fat Bear Week bracket (Courtesy of Katmai National Park)

The contest dates back to 2014's Fat Bear Tuesday, according to the National Park Service, and has plumped up to an event with 640,000 votes cast in 2020, a year that cried out for fat bear fun.

"It really has to do with these bears being so captivating," Law said. "It is incredible to see the transformation they go through from early summer until now and that's not something that in nature that we always get the chance to witness."

There's not much to see bear-wise in the winter, but from June to September, visitors gather in Katmai to see brown bears feed on the area's abundant salmon.

A dominant adult male might catch and eat more than 30 fish a day, and by the end of the fall, adult males can weigh over 1,000 pounds.

About 2,200 brown bears live in the park.

The National Park Service says the region where the park is located is "home to more brown bears than people and the largest, healthiest runs of sockeye salmon left on the planet."

Last year's Fat Bear Week winner, Bear 747, is competing again this year, and he may be the bear to beat. In September 2020, he weighed an estimated 1,400 pounds (636 kilograms), according to explore.org, and he's at least as big this year.

Fat Bear Week starts on Wednesday, Sept. 29, and concludes on Fat Bear Tuesday, Oct. 5.

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