32 Chunk, known for his girth and a scar on his muzzle, has become one of the most dominant males on the Brooks River. But is that enough for him to win Fat Bear Week?

32 Chunk, known for his girth and a scar on his muzzle, has become one of the most dominant males on the Brooks River. But is that enough for him to win Fat Bear Week? / via Katmai National Park & Preserve

Voting is now officially open in the 2023 Fat Bear Week competition, celebrating the ability of brown bears to pack on weight for their hibernation cycle in Alaska. To do that, they must gobble tons of fish — and luckily, they live near a thriving sockeye salmon run.

"Essentially those fat stores have to keep them healthy from late October till June," when the salmon return to the Brooks River, media ranger Naomi Boak of Katmai National Park and Preserve, told NPR.

"We have some of the largest bears on the planet," Boak said. "The big boars, the biggest guys, can get to be between 1,000 and 1,400 pounds."

But it's not just about the guys. Female brown bears also pack on massive heft, and they do it while raising cubs.

How Fat Bear Week works

The 12 brown bears are placed into a bracket, and voters decide who advances from each matchup. Voting runs from Oct. 4-10. You can cast votes from noon ET to 9 p.m. ET.

"You can follow the bears for years and really get to know their lives and their personalities and their soap operas," Boak said.

"We really love that children and teachers follow the bears," she added. Students can ask questions using a Google form.

Who is your favorite fat bear?

128 Grazer is well-known as a tough bear, competing for the best fishing spots. This summer, without cubs to care for, she has grown to a huge size.

128 Grazer is well-known as a tough bear, competing for the best fishing spots. This summer, without cubs to care for, she has grown to a huge size. / Naomi Boak/NPS

The contest — and yes, we are aware the contestants are refreshingly oblivious, being bears — might seem simple. Just pick the most rotund bear, right?

But many voters often give extra credit to any bear that dramatically went from a gaunt, emaciated creature in the spring to a portly ruler of the river in October. And some bears just gain fans with their quirks and personal stories.

Fans of 128 Grazer, known for her big blonde ears, are hoping this is her year. She's a recent empty-nester: having successfully raised two sets of cubs, she's been able to focus on herself.

"She has been putting in the work," ranger Felicia Jimenez said as the 2023 bracket was unveiled. "She was quite dainty in early summer, but now she is huge."

Grazer also has a penchant for preemptively attacking huge males to protect her offspring, so many of her male rivals gave her a wide berth this summer — including 151 Walker, her first opponent in the bracket.

Then there is 32 Chunk. The bear has always been large, but now he's gone from being playful and a bit unusual to vying for dominance.

"This 18-year-old boar is a light bulb shaped, Leviathan of a bear," Boak said.

"He's such a fun bear to watch," said Mike Fitz, a former ranger at the park who is on the board of the Katmai Conservancy, praising Chunk's individuality.

Then there are perennial contenders like the past champions 747, 480 Otis and 435 Holly. On the other end of the scale (literally) is 806 Jr., the cub who won Fat Bear Junior 2023.

How can the bears eat so much?

480 Otis is seen on the river on July 29, as he scarfed down salmon to put on weight for his upcoming hibernation.

480 Otis is seen on the river on July 29, as he scarfed down salmon to put on weight for his upcoming hibernation. / Naomi Boak/NPS

A photo of 480 Otis from mid-September shows the bear in his bulked-up state.

A photo of 480 Otis from mid-September shows the bear in his bulked-up state. / M. Whalen, via NPS

"Once bears enter hyperphagia in late summer, Leptin, the chemical that tells the body it's full, is suppressed," according to the Department of the Interior. "This allows bears to eat until it's time to sleep."

In people, hyperphagia is treated as a disorder — "the extreme unsatisfied drive to consume food," as one scientific paper puts it. In bears, the condition is a survival tactic, as they prepare to go without food for months.

"The record that we've observed is, 480 Otis, who's one of our oldest bears and four-time Fat Bear Week champion, has eaten 42 salmon in 5 and a half hours," Boak said.

The summer glut is also when young bears bulk up, to eventually reach adult size.

"Cubs are born at 1 pound and at the end of their first year, they could be 70 pounds," Boak said. "And in their second year they can end the season at 200 pounds."

The contest is a glimpse into the wild

"Brooks River is only a mile and a half long, and Katmai is more than 4 million acres," Fitz told NPR's Weekend Edition Sunday. "This is one of the largest national parks. It's larger than any that you're going to find in the contiguous United States."

Trails and roads only provide access to a small portion of the park and preserve.

"It's punctuated by large lakes and tall volcanoes. It has some of the wildest coastline in North America," Fitz said. "It's really an extraordinary place."

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Tags: Katmai National Park  fat bear week  bears  Alaska