PW: What drew you to the topic of ecological invasions [Out of Eden]?

Alan Burdick: I'd been collecting odd little stories about invasions, and then I heard about the brown tree snake, this Australian creature that ate [nearly] all the birds on Guam and was getting to Hawaii by crawling into the wheel wells of airplanes. I did a magazine story for the New York Times on it and realized there was a lot more to say. Everything I read about invasions was gloom and doom. I like the search for epistemological truth in the sciences and the mind-bending stuff in the world of nature. I'm interested in how scientists work, how they gather information. Scientists have been treating invasions as a natural experiment on how ecosystems work.

It's not like habitat destruction, not a question of "are we going to cut down ancient redwoods and put in a parking lot?" It's much more a question of "what kind of nature do we want?" Alien species suggests that people and nature can get along. We may not like the results, but it happens. There's some good news to be told, within certain parameters.

PW: This is not a charismatic megafauna book at all. One of the loveliest sections of the book is the one on leafhoppers in Hawaii's lava tubes.

AB: I liked the hidden world aspect of things like leafhoppers and copepods. There are a lot of changes taking place below the level of perception, which raises the question of what's going on down there, but also the question, "What difference does it make if you can't see it?" I liked that tension and I wanted to have fun with it.

PW: The book is also a kind of travelogue, especially when you're writing about being on the ocean tanker.

AB: I wanted to write about how species can travel because we can. We can hop in a plane; we can get on a ship. It's like a detective story in which the narrator is implicated. I wanted to own up to our role in invasions.

PW: Late in the book you mention that Central Park is nature to you, though at that point you don't know how many natives are there. Do you look at Central Park any differently now?

AB: I felt like that was a good place for the narrator to come from. A lot of people think, "So what, it's green, there's birds, that's nature." But there are different layers to what nature is, so there's understanding the microfauna or the difference between a redwing blackbird versus a starling. There's wonder, something joyful to be drawn from those differences. Now I live next to Fort Tryon Park, and there's a pair of red-tailed hawks outside the window. I'm much more attuned to natives versus nonnatives, especially in New York: there's a lot of nature there, it's not just nonnatives. They're now trying to reintroduce bald eagles at the upper end of Manhattan.

PW: Was there any part of the book you especially enjoyed working on?

AB: The coolest thing was [Kasthuri Venkateswaran] at NASA. He'd found new species that lived only at NASA, and they'd probably gone out on space probes—they were probably sent to Mars.

PW: That was one of the things that struck me: that the human habitat includes fellow travelers. It's innate in us to change the environment. Those God-like powers, they're tough.

AB: I don't think they're really God-like powers. We're basically doing what microbes do, we're just more self-conscious about it. The question is, what kind of changes do we want to make?