Endangered opens with a statement about the United States’ “rich array of animal life” made by a famous green-minded politician—President Richard Nixon. It was he who signed the Endangered Species Act (ESA) into law, and from this moment on, little in Mitch Tobin’s deeply reported book about the landmark legislation is pat or predictable. Some ranchers cooperate to help save endangered wolves. Some environmentalists stretch the truth, and the ESA, to suit their agenda. And Tricky Dick comes off as a conservative who in this case lived up to the “conserve” part of the term.In the end, Tobin sees the ESA as flawed but fixable, a tool that can indeed help species survive in the face of mounting threats, not the least of them climate change. Tobin knows so much about the ESA that it’s easy to understand why he’s a consultant to environmental groups. But Endangered sprang from a 10-part, yearlong series he did in his former life as a reporter for the Arizona Daily Star, a task that was aided and enhanced by a raft of colleagues, as well as reporting fellowships and the cooperation of many sources. This kind of deep, resource-intensive reporting is itself an endangered species.