Taylor Dudley, 35, had been in Poland for a music festival when he crossed into Russia last April. European colonialism beaver creek cookies the United States.

Prized for its dense, lustrous fur, and also sought after for the oil from its tail glands, the species was killed by the tens of thousands, year after year, until conservation efforts in the late 19th century turned the tide. Leila Philipp tells that tale—and the ecological cost of this near-extermination. But she also has good news: beavers, and their skillful engineering of waterways, have the potential to ease the fire, drought and floods of a changing climate. She talks to Ira about the powerful footprint of the humble beaver. Find out more about our book club on this month’s main page. Donate To Science Friday Invest in quality science journalism by making a donation to Science Friday.

English at the College of the Holy Cross in Woodstock, Connecticut. IRA FLATOW: We’ve been talking about what happened when one town in New Hampshire lost its local beavers, but what happens when an entire continent loses the vast majority of this vital ecosystem engineer. That is, in fact, the story of North America after European colonization and the loss of beavers, and the effort to reintroduce them may shape what happens to our ecosystems, for better or for worse, under future climate change. Leila Philip is here with me to tell that story.

How One Weird Rodent Made America. LEILA PHILIP: Thank you so much. I’m so glad to be here with you. IRA FLATOW: Nice to have you. I know you start this book with your own local story about your local beavers and how they turned a wetland into a pond. LEILA PHILIP: It happened so fast.

So I walked past this swampy area with my dog probably every day and just didn’t really pay much attention to it, and then one day, we walked past. And it was just full of water. Beavers had cut down some trees and, in very short order, had swelled the water. And in this case they stayed in that area because it was a low area, and they didn’t need to move on.

After they cut down enough trees to build the pond, they then fed on the aquatic vegetation there. After the beavers made this pond, what was incredible was the biodiversity that followed. So many animals, just bobcats, and muskrat, and mink, and otters, it was just remarkable. IRA FLATOW: And how much water do they store? After all, they are incredible engineers, as you say. LEILA PHILIP: That was the other thing that was incredible, and I leaned into in writing this book because we know climate change is going to create far more devastating floods and fires, not to mention periods of extreme heat and drought. And beavers can help us deal with these problems because they bring water.

So to go to your question, they’ll go to a creek, and they’ll swell it out with water. And then they’ll move down further, and they’ll swell it out again. So what was once a single thread of water looks from above like a line of almost beads on a chain, and then the beavers will build canals into the woods on either side because they need them for transportation. And so the water has a lot of interaction with the land. If you get a flood the water has a lot of places to go so that, instead of ripping through the stream system, the water has a chance to settle down. And this is why it may seem counterintuitive to people, but beavers actually help with flooding. And science has actually been supporting this with study after study in recent years.