The biodiversity crisis is very real and very dire. But University of Montana environmental philosopher Christopher Preston wants to draw our attention to some positive developments in the world of wildlife. He calls them "tenacious beasts" – the whales, bears, bison, otters, and beyond that have faced extinction in the eye, and made remarkable comebacks. Some have had help from humans, while others have done it on their own. And Preston says they should all give us hope for bringing more species back from the brink. He joins Megan Williams to talk about his book Tenacious Beasts: Wildlife Recoveries that Change How We Think about Animals.