In the Southwest U.S., biologists are talking about returning beavers to rivers they once inhabited in order to fight droughts — which are expected to get worse as the globe warms. Beaver dams create great sponges that store lots of water.
ANDREA SEABROOK, host: Fighting climate change with beavers? It's Science Out of a Box.</s>ANDREA SEABROOK, host: Some biologists say beavers could help drought by building dams. To get the story for our Climate Connections series with National Geographic, NPR's David Malakoff ventured out to the canyon lands of the American Southwest.</s>DAVID MALAKOFF: Southern Utah does not look like beaver country - lots of rocks, not many trees - but climb down into a canyon and you can find water, clear, cool water.</s>DAVID MALAKOFF: This is Deer Creek, near the town of Boulder. Once there were lots of beavers here, then about 100 years ago the fur trappers came. They killed the beavers and took their pelts. In fact, the trappers were so thorough that by the mid-1800s, the beavers had virtually disappeared.</s>DAVID MALAKOFF: Now, biologists want to bring them back.</s>DAVID MALAKOFF: Ms. MARY O'BRIEN (Grand Canyon Trust): If I'm a beaver I want a not-too-steep stream.</s>DAVID MALAKOFF: Biologists, like Mary O'Brien. She works with the Grand Canyon Trust and she knows a lot about beavers.</s>DAVID MALAKOFF: Ms. O'BRIEN: And I want kind of gooey mud to put up on my sticks and then I'm happen.</s>DAVID MALAKOFF: Believe it or not, O'Brien says that in a warming world, beavers could be a big help.</s>DAVID MALAKOFF: Ms. O'BRIEN: We're clearly facing climate change, less water, warmer water, water coming down in heavy storms when it does come down. And if we can get some of the best hydrological engineers on earth for free, it's the perfect timing.</s>DAVID MALAKOFF: Climate scientists predict that this part of Utah will get a lot drier, and O'Brien says beavers could help keep the water flowing by doing what they do naturally: building dams.</s>DAVID MALAKOFF: Ms. O'BRIEN: Now, for them it's a way of hiding from predators. For us, it's a way of slowing water down, recharging aquifers.</s>DAVID MALAKOFF: And making the water last longer into the summer. The idea is that the dams would hold back the snow melt that runs off the mountains each spring, giving the water time to soak into the ground.</s>DAVID MALAKOFF: Ms. O'BRIEN: Beavers actually turn the mountain into a sponge for the water, instead of a boom bust water in the spring, gone in the summer. It's water slower but all the time.</s>DAVID MALAKOFF: Studies from other parts of the country have shown that restoring beavers can improve water supplies. But the strategy does have some problems. For one, beavers can become giant swimming pests. They dam up irrigation canals and road culverts, flooding out gardens and driveways. Some places even have special crews that trap and move nuisance beavers.</s>DAVID MALAKOFF: But that doesn't bother Tom Hoyt. He owns a ranch along Deer Creek, and he says he'd be happy to take on some beavers that other people don't want.</s>Mr. TOM HOYT (Ranch Owner): There's a lot of beaver that need a place to go. I mean, it's almost like the Humane Society if you will. There is a source for sure.</s>DAVID MALAKOFF: But before any beavers can get moved, Hoyt says his neighbors along Deer Creek may need to be reassured. Farmers just downstream want to be sure they'll get their water when they need it. And just upstream is a big national forest that gets lots of visitors.</s>DAVID MALAKOFF: Robert MacWhorter runs the Dixie National Forest. He says, yeah, beavers can be a nuisance but they're also really cheap labor.</s>Mr. ROBERT MacWHORTER: Beavers can help us do an awful lot of management for a pretty small cost. You bet.</s>DAVID MALAKOFF: He says besides saving water, beaver dams create great habitat for trout, insects and birds.</s>DAVID MALAKOFF: Today, MacWhorter has come out to Deer Creek with Mary O'Brien, the biologist, and some local environmentalists. They're looking at places where beaver might be transplanted. As they get near the end of the walk, they find a surprise. They jump across Deer Creek…</s>DAVID MALAKOFF: One, two, okay, here I come. Thank you. All right.</s>DAVID MALAKOFF: And there sticking up out of the grass are willow shoots. They look like they've been lopped off by a machete.</s>DAVID MALAKOFF: Ms. O'BRIEN: Beaver do that. That's their thing. I think one of the beavers are in here.</s>Mr. ROBERT MacWHORTER: Sure enough, here's a willow stem that's been cut off just neat as can be. You can actually see all the ridges that were made by the beaver's teeth. We found something. That's way cool, way cool.</s>DAVID MALAKOFF: It seems these beavers didn't need a helping hand to find Deer Creek. The biologists say they probably moved up from somewhere downstream. But the beavers may need some help if they want to stay. Mary O'Brien notes that Utah still allows trappers to kill as many beavers as they want.</s>DAVID MALAKOFF: Ms. O'BRIEN: All can go for not if you get beaver restored on, say, Deer Creek and then one trapper comes in and cleans it out.</s>DAVID MALAKOFF: She and her allies are now working with the state to develop some new rules that would give beavers a little more protection.</s>DAVID MALAKOFF: David Malakoff, NPR News.</s>ANDREA SEABROOK, host: Coming up, a rebuilt version of the 1960s auto icon, the Mustang. It's called the Thunder Hawk, and it may actually contribute to global warming, but, hey, there are only three of them. Vroom, vroom.</s>ANDREA SEABROOK, host: It's NPR News.