This book was amazing!! And Jeff Corwin came to KSU to give a speech and I listened to him. He's funny, educational, and very passionate about his work. This comes across in his book as well. So basically this book talks about animals that are on the extinction list and how there are literally only 100 of them left, hence 100 heartbeats left in the world of that particular species. Now when you stop and think about that, that's pretty depressing. He talks about different conservationists that specialize in bringing back one species of animals and how they are trying to do that. The story about the condors in CA was pretty heroic! It involves a fire up on a mountain and the the conservationists trying to carry these birds out on four-wheelers and they run out of gas and there is just so much smoke they can't find the helicopter. And that's just one of the stories! This book is very sad though to think about how humans and our carelessness to our planet is causing the demise of so many creatures and how that will have a HUGE effect on the ecosystem and in turn on us. But this book leaves you with hope and that's why I loved it so much. Even if your not an animal lover I incourage you to read this book!!