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Fat Bear Week’s bears survived a historically hot summer

Fat Bear Week’s bears survived a historically hot summer


The heat took a toll on a vital food source for the bears

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Despite the online excitement about Katmai National Park’s fat bears this year, the critters struggled harder than usual to plump up. The heat hit an important bear food source — salmon — hard, and that makes the bears’ future uncertain.

Last July was the hottest month ever in Alaska — bringing a longer-than-usual fire season and the state’s first “extreme” drought. To beat the heat, bears spent more time than usual lounging, which may have cut into their time foraging for food. And Alaska’s salmon, a favorite bear treat, were found dead along rivers and streams before getting upstream far enough to spawn.

A fat bear is a healthy bear

A fat bear is a healthy bear, which is part of why Katmai National Park’s competition — now in its fifth year — exists. Holly, a heavyweight in Katmai’s annual competition was named this year’s champion during Fat Bear Tuesday on October 8th. The bears have a lot of online human fans who voted for their favorite bear on Facebook. The winner in the tournament is a testament to the bears’ ability to adapt in a warming world, experts say, but many brown bears aren’t faring as well. And it could be too early to tell whether the salmons’ struggles to spawn this year could mean less seafood dinners for the bears in the future.

Fat Bear Week Champion Holly before and after plumping up on Brooks River Salmon
Fat Bear Week Champion Holly before and after plumping up on Brooks River Salmon
National Park Service / K.Stenberg, L.Carter

Naomi Boak, a Katmai Conservancy media ranger behind the Fat Bear Week campaign, tells The Verge that the bears struggled with the soaring temperatures, too. “Imagine being in 90 degrees, being really fat, and having a big fur coat,” Boak says. “This is not pleasant.” A fat bear’s surface-to-volume ratio alone can make it harder for the bear to cool itself down.

“Imagine being in 90 degrees, being really fat, and having a big fur coat.”

Salmon that survived the heat spent more time out in the ocean and in deeper, cooler water, keeping the bears waiting. “I’ve been out there before, when a [salmon] run was delayed by a week, and the bears start getting anxious,” says Joy Erlenbach, a PhD candidate at Washington State University’s Bear Center, who has studied the bears in the park. “It’s scary for the bears because they don’t know what’s happening. They just know the food they expect isn’t there, and it can affect their behavior.” 

There could also be cascading effects if the salmon prove to have been less successful spawning this year. “If this affects the salmon return in years to come or we continue to see significant events that cause a decrease in salmon spawning, then it could lead to a decrease in that food source for bears,” says Katmai wildlife biologist Leslie Skora.

It’s not clear that the heat and salmon shortage would spell doom for the bears — they’re consummate omnivores, after all. That may make it easier for them to adapt to a warming world, even if it means chasing down the occasional stolen gallon of ice cream. This year was a strong year for cranberries in the park, Skora says. 

Bear 747 was a fan favorite this year
Bear 747 was a fan favorite this year
N. Boak / Katmai National Park

Erlenbach worries that fans of the Katmai competition might not realize the threats that face Alaska’s bears. Katmai is one of the best places in the world for a bear to find a meal, especially for the lucky ones who get to catch salmon along the Brooks River. So if it’s getting tougher here, that doesn’t bode well for less fortunate bears. “The top 20 fattest bears in the world are the ones that are getting the press right now,” she says. The skinniest bears — the ones we should worry about — aren’t.

Update 10/9/19 8:21AM ET: This post has been updated to include the champion named in this year’s Fat Bear Week Competition.