Bears gorge on salmon ahead of Alaskan winter

Stop.

--to be at this time of year. This is a live picture courtesy of explore.org and Katmai National Park. The park sees the largest population of coastal brown bears, thanks to the migration of sockeye salmon. So actually, the pictures that you are looking at, that is a bear doing exactly what it's doing right now. Let's bring in Troy Hunt. He's a park ranger at Katmai National Park and Reserve. Troy, thank you so much for joining us here. It's a great, fun topic on a Friday. So why do so many bears gather at Brooks Falls? And how does that help the overall ecosystem of the park? So the Bears gather here because we have one of the world's largest run of sockeye salmon anywhere. The Bristol Bay area has that biggest run. And up through the Naknek River drainage, up through Brooks Falls, we have that. And the bear come there because, as we can see here, plenty of salmon to eat, as that lovely catch right there on the lip. They are coming to, as you mentioned, bulk up because they have winter coming, and they have to almost double their body size, in many cases, to have enough body fat to be able to survive through the winter hibernation period.

So how do you keep track of these bears? And I think people will want to know why studying them is so important for bear conservation.

When we are studying, keeping track of these bears, we have people, who, it's their job. They come out and do actual on-site observation. Unlike other places where Bears are tagged with collars and tracked, we don't actually do that here. We let the bears be wild. And so one of our rangers, it's specifically her job to go out and do sampled observations of the bears in multiple locations in the park to keep track of them. And she identifies them and gives them numbers. For example, the bear that we were just seeing on there, this is a nice surprise for this morning. That is bear number 32, Chuck, who we have not seen a lot. That was the winner of last year's Fat Bear Week.

Just wanted to clarify, his name is Chunk?

Chunk.

Chunk, C-H-U-N-K. Bear number 32 is his official designation. But because he was a chunky bear when he was small, then the viewers are the ones who give them these names, and they said he's a Chunk. And so Chunk is what stuck. And he lives up to that. He was massive last year.

Well, we're not going to fat shame the bears, even though I love the name Chunk. So we understand the idea of the hibernation and building up the blubber so that you stay warm. Why do they need to start so early to do that? Well, they live off of their fat storage all winter long. And so when they come out of hibernation, they have lost up to about a third to sometimes almost a half of their total body weight from the year before. And so as soon as they come out of hibernation, they start to eat. Early on, they are true omnivores, so they will eat lots and lots of plants, berries that are left over from the previous season, and they are waiting for when the salmon run in July here at Brooks Falls, specifically, so they can come and gorge on about 4,000 to 5,000 calories per fish. And the record of that was a bear named Otis, we don't see anymore, who, in a day, ate 43 fish, which is about 160,000 to 200,000 calories over a five-hour period. Wow. So well beyond anything we can imagine because they have to bulk up and bulk up and bulk up. And they're just-- [MUNCHING] So every time-- I love this story so much that I'm a nerd. I once, many years ago, wanted to understand why-- we're mammals. Would you agree, we're mammals? Why are humans not able to hibernate like bears? And I got down this rabbit hole of bear evolution and how not only do they store that food for energy and for fat and how it keeps them insulated, but how they even can defecate. There's very interesting reasons why-- You got down the rabbit hole. --and how bears and how their brains stay active, even though they're hibernating, and how we're unable to do that. There is so much to be learned, I guess, is my point in studying bears and how they behave, specifically when they're hibernating, Troy. Absolutely. Their bodies adapt very, very differently than ours. We can't manage to hibernate. But studies of their biology, where they eat so many calories and gain so much fat, you'd think that they'd have bear diabetes. But their bodies adapt differently. And they develop different levels of insulin resistance, depending on the time of year. And when they're hibernating and living entirely off their fat stores, then their metabolism slows down a whole lot, and they are then able to live off of that fat. But then in the summertime, when they're gorging, like you see, this bear-a-palooza here at the falls, as they are chewing down on that salmon there on the lip, their bodies adapt. There are researchers who are trying to understand that change in insulin resistance in bears, to see if it might be a panacea or a cure to help us deal with diabetes in humans. But there's no major steps forward in that. It's just early research that I've read this summer. And by the way, fun fact, Kelly, do you know that polar bears don't hibernate? No. I know though, if it's white, good night. So I hope I never see a polar bear. Yeah, because exactly, because they so rarely see humans that if they see you, they're going to be like, hmm, looks pretty good. Troy, thank you so much for joining us. This is such a fun way to spend the Friday. It was a pleasure. Thanks for having us here on this foggy morning at Katmai. Live pictures there, very cool.