Zoos take care of animals and welcome visitors of all ages, but that's not all zoos do. Author Patricia Newman and photographer Annie Crawley bring readers behind the scenes at three zoos to meet scientists working to save endangered animals.

Meredith Bastian's experiences studying wild orangutans help educate both zoo visitors and the zoo workers who care for captive orangutans. Jeff Baughman breeds black-footed ferrets and reintroduces them into the wild. And Rachel Santymire examines poop from black rhinoceroses at the zoo and in their natural habitat to benefit all black rhinos. Find out how zoo scientists are helping us learn more about these remarkable, at-risk species before it's too late