Snakes of the Eastern United States

The short version of this review: remember Snakes of the Southeast, the field guide by Whit Gibbons and Mike Dorcas, the second edition of which I reviewed last year and thought so highly of? Well, now Gibbons has done the same thing, only covering the entire eastern United States, with (appropriately enough) Snakes of the Eastern United States (University of Georgia Press, April 2017). Go get it.

But maybe I should expand on that a bit.

What impressed me about Snakes of the Southeast is that it knew its intended audience: not scholars, not hobbyists, but the general public. And in pitching itself at that audience, it knew what questions needed answering. As I said in my review last year:

The core of the book, the species guide, is detailed but plain-spoken, and does not drown the reader in scholarly references. It’s beautifully laid-out, with full-colour range maps and photographs of the region’s snakes. Its identification guide eschews the detailed scale counts used by professional herpetologists in favour of emphasizing distinctive traits and other factors more easily recognized by amateurs. And with two additional chapters explaining basic snake biology and exploring the relationship between snakes and humans, Snakes of the Southeast becomes a one-book solution: the book that tries to cover all the bases and answer all the questions about snakes that someone in the region might reasonably have.

Snakes of the Eastern United States follows that prescription down the line, which is no surprise given that it shares an author and a publisher with the previous book. The many virtues of Snakes of the Southeast, above and beyond being a species guide, are now accessible to people from outside that region. I’ve got a book I can recommend to more people.

In terms of its function as a species guide, as well as on field guides in general, though, I have a few thoughts.

Once again, this book takes an extremely conservative position on snake taxonomy. Rat snakes, for example, are called Pantherophis instead of the old Elaphe, but the traditional subspecies are maintained “because in most cases ratsnakes from particular geographic regions are easily identifiable based on color and pattern” (p. 198). Neither does Gibbons separate out the Common Kingsnake (Lampropeltis getula) into separate species, nor adopt the more recent taxonomic changes to swamp, crayfish and milk snakes. One gets the impression he sees these changes as for change’s sake.

Regional field guides have interesting edge cases, especially when they’re defined by political boundaries (a country, state or province) that don’t necessarily line up with bioregions: there’s always something atypical living in the borderlands. Gibbons defines the eastern United States as every state east of the Mississippi, excluding Minnesota but including Louisiana. So in this case we get central and western species like the Western Worm Snake (Carpophis vermis), Western Hognose Snake (Heterodon nasicus), Great Plains Rat Snake (Pantherophis emoryi) and Lined Snake (Tropidoclonium lineatum) at the edges of Gibbons’s maps. Illinois is usually the culprit.

(Speaking of maps: the map for the Butler’s Garter Snake [Thamnophis butleri] doesn’t include its Wisconsin range—a surprising omission given its politically charged status in that state.)

Then there’s the question of how the species are organized. This is actually an important consideration when the guide covers a large area or a large number of species. Some guides, simply list them in alphabetical order after sorting them by family (e.g. boas, colubrids, pit vipers) or separating the nonvenomous from the venomous snakes: this is the approach taken in Ernst and Ernst’s Snakes of the United States and Canada, Rossi and Rossi’s Snakes of the United States and Canada (no relation), and Werler and Dixon’s Texas Snakes. Others, like Alan Tennant in his state and regional field guides, categorize them in some fashion, e.g., small snakes versus aquatic snakes versus large terrestrial snakes.

Gibbons takes the latter approach, which necessitates some odd judgment calls, like splitting the kingsnakes between the midsize and large terrestrial snakes categories, or putting the closely related (and not that different in size) Short-headed Garter Snake (Thamnophis brachystoma) and Butler’s Garter Snake in the small and midsize categories, respectively. It’s the edge cases that’ll get you every time.

But these are quibbles, and there are always quibbles in books like these, which involve the compilation of a huge amount of field data, scientific knowledge, photography and text that must somehow come together in a whole that is not only coherent, but readable. This book achieves that end result far better than most.

I received an electronic review copy of this book via NetGalley.