In the midst of Fat Bear Week ― the time when Alaska’s Katmai National Park celebrates brown bears bulking up for winter hibernation ― an unlikely friendship has formed.
A mother brown bear and her cubs typically don’t spend a lot of time with other bears. But this year, two mothers with a single cub each have formed an ursine quartet that’s been playing, resting and fishing for salmon together, Mashable reports.
During Fat Bear Week, enthusiasts can vote on their favorite fat bear of Katmai in a March Madness-style bracket. People can also watch the hefty contenders via a live “bear cam” through Explore.org, a website that hosts various animal-centered livestreams.
The mama bear BFFs ― known to humans as bears 909 and 910 ― are actually sisters, though this relation doesn’t make their current closeness less noteworthy.
“I’ve never seen two families associate with each other like these have,” Mike Fitz, a former Katmai park ranger now Explore.org’s resident naturalist, told Mashable.
Naomi Boak, Katmai’s former media ranger, called the friendship “pretty incredible,” saying that for her, it was the “story of the year.”
Fat Bear Week’s origins date back to 2014. Fitz, then working for Katmai, posted a series of “before and after” photos of the bears on the park’s Facebook page and encouraged viewers to vote on their favorite.
“The one-day event, Fat Bear Tuesday, had a really high level of engagement—far more engagement than anything else we had posted on social,” Fitz told Smithsonian Magazine.
The next year, the park staff decided to make the voting a week-long affair, and Fat Bear Week was born. Since then, the annual bear-to-bear matchup has grown in popularity, and the winning bears typically receive national media fanfare.
“Every year, the fans return to Katmai virtually, and it’s like they’re seeing these long lost relatives return, and it fills their hearts with joy,” Charles Annenberg Weingarten, the founder of Explore.org, told Smithsonian.
Last year, the voters’ favorite bear was Otis, a 25-year-old bear who had experienced some health issues earlier in the year before joining in the annual salmon chowdown.
In this year’s bracket, Otis is still in the running and defending his title as of Saturday.