The contenders for this year’s Fat Bear Week were not revealed Monday as planned, after a skirmish between two Alaskan grizzlies in Katmai National Park led to the death of one of the animals. Their fight was captured on a livestream run by the multimedia organization Explore.org, which partners with the National Park Service to host the annual bear competition and shares video online for fans to follow along and vote.

“Earlier today, a bear killed another bear on the river. It was caught live on the webcams and we thought, well, we can’t go ahead with our Fat Bear Week bracket reveal without addressing this situation first,” said Mike Fritz, the resident naturalist at Explore.org, in a conversation on Monday’s livestream held in place of the scheduled unveiling. The 2024 Fat Bear Week bracket reveal has been postponed until Tuesday at 7 p.m. ET.

The fight between a male brown bear and an older female — one of the contestants last year known as Bear 402 — unfolded at the mouth of the Brooks River in Katmai, a protected area on the Alaskan peninsula that draws some of the region’s largest grizzlies to feed on sockeye salmon, according to the National Park Service. The bears are currently hunting the end of the seasonal salmon run as they prepare to enter hibernation during the coming winter months.

“National parks like Katmai protect not only the wonders of nature, but also the harsh realities,” the National Park Service’s Matt Johnson said in a statement obtained by KTUU after Bear 402 was killed. “Each bear seen on the webcams is competing with others to survive.”

Fritz said the bear’s death, and what led up to it, was difficult to watch. He and Sarah Bruce, a park ranger at Katmai, discussed the circumstances that could have precipitated the fight between 402 and the male bear, 469, which they agreed was too drawn out for an ordinary confrontation over food.

“We do know at this time of year that bears are in that state of hyperphagia, and they are eating anything and everything they can,” Bruce said. “I don’t know why a bear would want to expend so much energy trying to kill another bear as a food source. It’s an uncommon thing to see a bear predating on another bear, but it’s not completely out of the question. So it’s hard to say how this started.”

Hyperphagia is the bears’ winter preparation process, where they spend almost all of their time eating and drinking to bulk up before retreating into their dens. Surviving hibernation depends on how much they can eat during this phase of the year, wildlife officials say.

Fat Bear Week is billed by the National Park Service as “a celebration” of their success as hibernation approaches. Cameras track a roster of massive grizzlies that call Katmai home as viewers watch and vote for their favorites, which then advance through several rounds until a winner is crowned. As lighthearted as the event can be, Fritz said what happened Monday was a reminder of the threats these bears often encounter in the wild.

“We love to celebrate the success of bears with full stomachs and ample body fat,” said Fritz. “But the ferocity of bears is real, the risks that they face are real, their lives can be hard and their deaths can be painful.”

Fritz said Bear 402 was “beloved.” The animal likely died by drowning, he added.