Fat Bear Week 2023: Can chubby cub 806 Jr beat the seasoned champions?

His bodyweight has increased nearly 7,000% since the day he was born, which was less than a year ago.

And now this 70lb (31kg) spring cub, known as 806 Jr, is taking on the champions of chonk in this year's Fat Bear Week competition.

The popular online event, founded in 2014 by former park ranger Mike Fitz, has become something of a phenomenon, with more than a million votes cast last year for the fattest of them all.

Each year, the brown bears of Alaska's Katmai National Park gather along the banks of the Brooks River to devour salmon swimming upstream. Their goal: to pack on as many pounds as possible before winter.

Twelve bears among the lot are chosen for Fat Bear Week's bracket, where fans voting online will ultimately decide the winner.

806 Jr, recognisable by his short muzzle and near-Disney-level cuddliness, is already the 2023 Fat Bear Junior Champion - but can he match the chub of more seasoned veterans?

The current favourites for 2023's contest are 480 - aka Otis - a 27-year-old brown bear weighing roughly 1,200lb, and 747 - or Colbert - a two-time Fat Bear Week champion weighing about the same.

It's an uneven playing field, not separated by bear gender, size or age, says Mr Fitz, now a resident naturalist at explore.org, which maintains a 24-hour livestream of the bears.

Roughly 10 million people tuned in to the Katmai livestreams in 2022, including to watch the bears jockey for position at the best fishing spots.

"If you're a guy like 747 (Colbert), you don't have to worry about bears challenging you, so you can do what you want, when you want," Mr Fitz says.

Otis, meanwhile, is a four-time champion and a "beloved" bear with a good chance of winning.

Though he's ageing, is missing a few teeth, and can no longer fight for the prime salmon spots, Mr Fitz says: "I definitely wouldn't want to count him out."

Brown bears in Katmai need to eat a year's worth of food in about six months to store enough fat to survive the winter.

"A good day's catch for a bear is about 10 salmon," Mr Fitz says. "But they can eat much more than that."

He once saw a bear eat 42 salmon - roughly 189,000 calories - in just five hours.

However, that's small fry for the hungriest hunters. Some bears have been estimated to eat up to 6,000lb in a single summer-fall feast.

Consuming such large amounts of food can lead to massive weight increases, with the spring cubs like 806 Jr seeing some of the heftiest jumps.

Spring cubs typically weigh just 1lb when they're born in January and February, but by the end of fall can exceed 70lb.

Young-adult cubs can double their bodyweight over the same time period, going from 200lb to 400lb, Mr Fitz says.

The really big males will gain about 200-300lb and can weigh as much as 1,600lb by the end of a summer binge.

However, Mr Fitz says: "Mother bears are particularly challenged to get fat."

"When you compare the body size and shape of many mother bears, there's often a noticeable difference between the mothers and the single males and females."

That's a disadvantage to Fat Bear Week competitors like 435, aka Holly, aka "supermom" - who can expend significantly more energy protecting their cubs and producing milk.

Known to fans for being "the color of a lightly toasted marshmallow", as the contest puts it, Holly weighs somewhere in the ballpark of 800lb.

But, her smaller size didn't stop her from Winning Fat Bear week in 2019. That's because, according to Mr Fitz, size doesn't always matter.

"Fat Bear Week is about telling the diversity of the stories. It's not about who can win the bracket," Mr Fitz says.

And, it's about a "celebration of the work and success of brown bears".

Fans can vote on Explore.org's website every day of the competition, from 4 October to 10 October, between 12:00-21:00 EST (16:00-01:00 GMT).

The first Fat Bear Week in 2014 attracted a couple of thousand votes, but has since gone global. Its fandom has grown so much that, in September, people tuning into the live stream eager to spot a bear instead located a stranded hiker, saving his life.