"Fat Bear Week" is a popular bracket tournament in which the brown bears of Alaska's Katmai National Park & Preserve go belly to belly.
The sockeye salmon are plentiful in Alaska's Katmai National Park & Preserve, and so are the brown bears. In fact, there are more brown bears than people in this particular region, according to the National Park Service.
Why are we spitting out random stats about bears and fish? Well, it's not random at all. Today begins the annual Fat Bear Week at Katmai, the culmination of a season-long "competition" between the large-and-in-charge mammals. Before hibernating in winter, they have to pack on the pounds, eating as many salmon as they can find.
Fortunately in Katmai's water-rich ecosystem, the bears enjoy a virtual buffet of all-you-can-eat sockeye. People log on from far and wide to watch these guys chow down.
Park rangers and experts create a tournament bracket of individual bears to determine which will emerge the fattest. As you can imagine, the annual competition in which viewers vote for their favorite contenders has become wildly popular since beginning as "Fat Bear Tuesday" in 2014.
Here's more from the NPS on Fat Bear Week:
"Fat Bear Week — an annual celebration of success. All bears are winners but only one true champion will emerge. Held over the course of seven days and concluding on the Fat Bear Tuesday, people chose which bear to crown in this March-Madness style bracket where bears are pitted against each other for your vote."
Watch a live chat that dives deeper into the ecosystem, the bear contenders, and the reveal of this year's bracket.
And when you are ready to research and vote for your favorite, visit and keep tabs on the competition here.
At the website, you can meet the bears in contention and — here's what got us — you can also meet the junior bears competing for glory. That's right: there are now two levels of fat-bear competition!
Oh, and about that lead image: It's Otis, last year's Fat Bear Week winner (and repeat champion).
Can someone unseat Otis from the Fat Bear mountain? We'll see.