Somewhere over your town right now, a turkey vulture is turning slow circles in the sky. It's been doing that — or something very close to it — for five million years. It outlasted ice ages, mass extinctions, and the disappearance of entire species. And today, it's being slowly poisoned by lead ammunition, rodenticides, and the simple fact that most people have never stopped to appreciate what it does.

This episode is a defense of the turkey vulture: its history, its biology, its indispensable role in keeping ecosystems — and us — healthy, and what we can do to protect it.