Climate Change: Making The Nation's Bears Hungry?

Originally published on April 24, 2011 3:47 pm

National Parks Week kicks off Saturday, but the celebration comes at a rough time for National Parks. Harried by federal funding cuts and urban development, the nation's park system is also facing the rising threat of climate change.

Those effects are becoming most visible in Yellowstone, one of the best known of all national parks, according to Paul Solotaroff. He wrote about Yellowstone's climate challenge in April's issue of Men's Journal and tells Weekend All Things Considered guest host Noah Adams that the damage is putting the park's ecosystem out of balance.

"In the last decade, there has been just an endless siege of dry and unusually hot stretches that have thinned out the streams and lakes, that have made it very difficult for trees to regenerate at the highest elevations, among them the lodgepole pine and whitebark pine, which are the signature of the Yellowstone greater ecosystem," Solotaroff explains.

As a consequence of the heat and dryness, pine beetles have infested the trees and left many of them dead, he says. This is a big problem for Yellowstone, as the pines are especially essential to the park's inhabitants. They provide shade, stabilize the soil and, perhaps most importantly, feed the local grizzly bears.

The tree's pine seeds are core to the bears' diet. Without it, the animals become increasingly desperate to find food, Solotaroff explains.

Yellowstone had two grizzly bear attacks last year, something that hadn't happened in the park in 24 years. The first was an accident: A hiker crossed paths with a bear that had been sedated by a team of federal researchers. The second attack was by a mother bear searching for food. She injured several campers before ultimately killing a medic from Michigan who had come to Yellowstone to fish in its streams.

Pine seeds are only part of the bears' problem, Solotaroff says. Trout, another part of the bears' diet, are dying as a result of rising temperatures in the streams. All of this, he believes, can be linked back to climate change.

Despite the attacks and the infestations, Yellowstone told NPR in a statement that the issues are too broad to scientifically connect to climate change. Solotaroff disagrees.

"Every reasonable scientist, every reasonable arborist, agrees that there is a very tightly knit connection between the availability of food supply and the behavior of these bears," he says.

"What is driving these bears into populated places is hunger, and that hunger derives from the ripple effects of the warming of the last 10 years and the significant but more gradual warming of the last 30 years in the American Northwest."

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[POST-BROADCAST CORRECTION: Bear attacks have occurred near Yellowstone, but not within the park's boundaries.]

NOAH ADAMS, host:

Today marks the beginning of National Parks Week, featuring free admission through the 24th of April. It's been a tough time for the parks lately, the system is threatened by federal funding cuts, urban development, and climate change. And the effects of climate change are dramatically visible in one of the country's best known national parks. In Yellowstone, the whitebark pine trees are affected by the increase in temperature. The whitebark seeds are a basic food for the grizzly bears. Last year, grizzlies attacked several visitors, killing two.

Paul Solotaroff writes about it in the April issue of Men's Journal. He believes there's a definite connection.

Mr. PAUL SOLOTAROFF (Writer, Men's Journal): About five, six years ago, arborists began to notice that these extraordinary trees that have for many, many thousands of years survived winters at 50, 60 below, suddenly were dying and not dying by the handful, but dying by the stand, eaten alive by something called mountain pine beetles.

ADAMS: So the beetles, they can now - it's now hot enough so they can go to work.

Mr. SOLOTAROFF: They can go to work and they can now spend the winter inside these trees, hatch their larvae, survive the winter themselves and attack the trees they've set up shop in and then fly to new trees and eat them alive as well.

ADAMS: Now, tell us about the attacks on the campers in Yellowstone. How many people were killed? How many were injured? What was going on there?

Mr. SOLOTAROFF: Well, there hadn't been a bear-caused fatality in two and a half decades in Yellowstone. And over the course of six weeks, two people were killed. One, a most unfortunate episode in which a botanist was wandering in an area that had just been visited by a grizzly bear study team and they'd found a grizzly and they'd knocked him out to take hair samples, tooth samples and the like. And they didn't post signs warning that they were there and there was a bear that had been sedated. And so this poor guy wandered into a clearing, and there he found the bear waking up. And the bear killed him and ran away.

And then six weeks later, a tragically thin mother bear and her three cubs wandered onto a campsite where they smelled cooking fish, and they attacked several campers and then finally wound up killing and devouring an EMT from Michigan.

ADAMS: You have a very scary sentence in your article about the hunger of the bears. It is this: So desperate have they become that they run toward gunfire, having learned that hunters leave gut piles after a kill.

Mr. SOLOTAROFF: Yeah. It isn't just the lack of whitebark and those fleshy seeds. I mean, bears need to eat 13, 14,000 calories a day to maintain body weight and also fatten up for the four or five months they go to sleep. And if it were only the pine nuts that had become scarce, they'd probably be able to find a compensating food source.

The problem is that the fish are dying as well. The streams have gotten so warm, because the summers are longer. The runoff from snow is skinnier, meaning that by July and August, the fish are dying of heat stroke essentially. And so bears who could depend upon cutthroat trout and brown trout and rainbow trout to pad out their protein diet are now going hungry in trout streams as well. And it's this kind of, you know, deprivation that is turning bears increasingly desperate.

ADAMS: Now, about global warming, we contacted the Park Service. They say there have indeed been bear attacks in the park and, yes, there is a pine beetle infestation, but that these issues are too broad scientifically to connect directly to climate change. How do you feel about that?

Mr. SOLOTAROFF: It's nonsense. Every reasonable scientist, every reasonable arborist, agrees that there is a tightly knit connection between the availability of food supply and the behavior of these bears.

Bears are starving, you know? The bear that was captured after killing the EMT from Michigan was grossly underweight, as were her three cubs. But what is driving these bears into populated places is hunger, and that hunger derives entirely from the ripple effects of the warming of the last 10 years and the significant but more gradual warming of the last 30 years in the American Northwest.

ADAMS: That is writer Paul Solotaroff. His article on Yellowstone appears in April's issue of Men's Journal.

Thank you, Mr. Solotaroff.

Mr. SOLOTAROFF: A great pleasure. Transcript provided by NPR, Copyright NPR.