Playing God in Yellowstone

"I used this book both for A Friend of the Earth and for my current book, When the Killing’s Done . This is a book about the biggest national park in the US. We Americans think the streets may be degraded but at least we have Yellowstone, at least there’s a wild place. Here is the most managed ecosystem in America, maybe in the world, and it’s been a dismal failure for a simple reason – we removed the predators because tourists like to see pretty animals like elk and deer and moose. Their numbers were fewer when predators were at large, so the predators were killed off. The results were catastrophic. It first appeared among the beavers. There were suddenly fewer beavers, so the streams were not dammed up. Why fewer beavers? Because there were no wolves, who normally eat the deer and elk, so the deer and elk ate all the river banks down to nothing, and the whole ecosystem began to collapse. Recently wolves have been reintroduced to great effect. He comes to the conclusion that we destroyed an ecosystem that we were trying to manage and protect, with the best of intentions. He is an advocate for trying to manage ecosystems not by killing predators, but by introducing them."