What is the author's style in The Song of the Dodo: Island Biogeography in an Age of Extinctions by David Quammen?

Quammen's larger subject is the natural environment and the changes it is undergoing presently and he approaches it as someone with a great appreciation for the diversity of nature and concern about the potential for losing that diversity. He stops short of drawing many conclusions himself, however, instead positioning himself as an interpreter of the prevailing scientific thinking on the subject of biogeography as well as the history of the development of the field.