Welcome to Fat Bear Week at Mashable! Each fall, Katmai National Park holds a competition as Alaska’s brown bears finish fattening up for their long winter hibernation. This year, Mashable is getting in on the salmon-munching action. Check back with us all week as we follow the fat bear face-offs each day, and remember to get your votes in for each round. Happy fishing!

After consuming exceptional quantities of salmon this summer, Bear 409 "Beadnose" has triumphed as the 2018 Fat Bear Week champion.

She toppled a formidable contender in Bear 747, a dominant male bear whose enriched belly nearly scraped the ground.

Both bears — voted upon by the public on Katmai National Park's Facebook page — are unquestionably victors in their wild bear world, an Alaskan subarctic environment where snow has already fallen, and the winter looms large.

Simply put, the fatter a bear, the more likely it is to survive a six-month long winter hibernation.

"Both Beadnose and 747 demonstrated success in a challenging environment," Mike Fitz, an ecologist and former Katmai ranger, said over email. "They showed that their skill and experience can reap big caloric rewards."

Bear 409 Image: nps Bear 409 Image: nps

Bear 747 Image: NPS Bear 747 Image: NPS

Katmai National Park began the online Fat Bear Week competition three years ago as a way to relate the ursine ongoings in one of the most remote national parks to the greater public. (To get there, you must take a floatplane into the deep Alaskan wilderness and land on a glacial lake).

This season featured 13 bears that rangers observed fattening up between June and September.

Each of them, munching 4,500-calorie rich sockeye salmon throughout the summer, became noticeably engorged — though none quite as fat as bears 747 and 409.

Bear 409 became something of an internet sensation after Katmai tweeted a gif of her transformation from skinny to fat over the course of the summer.

The final Fat Bear Week bracket. Image: dustin drankoski/bob al-greene/mashable

She's also a well-known mother to several past cub litters, but 409 certainly benefited this summer by not having any cubs. She didn't need to share any fish with her largely helpless offspring, and had the weight gain to show for it.

Conversely, Bear 435 "Holly" — a mother bear famous for once "adopting" an abandoned cub, had two excitable cubs in tow. Holly, while certainly fattening up, was unable to put on the extreme weight she has in past years when she was roaming the river as a lone bear. Bear 435 lost in the Fat Bear Week quarterfinals.

Fat Bear Week, in all its online glory, has come to its 2018 end. But it's quite likely both bears 747 and 409 will be back next summer, and consuming copious amounts of salmon under the watchful eyes of the explore.org webcams.

These wild animals live in a far-off realm — a land of lynx, bald eagles, wolverines, and rivers turned red with fish. But the web gives us a glimpse into their wild world; a world in which this year, 409 proved to be the fattest of all the fat bears.