Tuesday, August 26, 2008

Review: Peterson Field Guide to the Birds of North America

In honor of the centennial of Roger Tory Peterson's birth, which will occur on Thursday, Houghton Mifflin commissioned a new edition of his famous field guide. This time the publishing company broke with tradition by publishing a guide that covers all of North America, instead of separate eastern and western guides. The Peterson Field Guide to the Birds of North America now joins the Sibley Guide and the National Geographic guide as the third illustrated field guide covering all of the ABA area.

The new guide fits very well within the Peterson tradition. Most of the paintings are his (though some are digitally enhanced), as are the silhouetted bird forms interspersed throughout the guide. New illustrations, painted by Michael O'Brien, are difficult to distinguish from Peterson's. Similar species are grouped together on a page in similar poses, as in the past. (One change: "Confusing Fall Warblers" have become "Selected Fall Warblers.") While the paintings are mostly the same as in past guides, the colors are far more vibrant so that the brush strokes almost leap from the page.

Text and a range map for each species is placed opposite the plates. The text, written in Peterson's laconic style, was thoroughly revised by Paul Lehman and Bill Thompson so that it would reflect current knowledge of birds' taxonomy and distribution. The text is supplemented by video podcasts at www.petersonfieldguides.com, which introduce bird families, some iconic species, identification tips, and the biography of Roger Tory Peterson.

Aside from stylistic similarities, it maintains use of the Peterson Identification System. The system breaks down identification problems into discrete steps. First, narrow the range of possibilities based on size, shape, and behavior. Then use field marks and voice to make an identification. Peterson's illustrations aid this process by emphasizing only the most important aspects of a bird's shape and plumage. Arrows point to the diagnostic field marks.

The system was innovative when Peterson published his first field guide in 1934. Previous guides had made use of identification keys, which frequently relied on marks or measurements that are not easily observable in the field. That first guide hastened an ongoing shift in bird identification from shotguns to binoculars and opened bird watching to more people. The Peterson system has since been overtaken by contemporary identification methods, which incorporate greater detail and recommend a more holistic approach. Yet Peterson's simplified method continues to provide a sound introduction for incipient bird watchers. I still use a step-wise method like his when I am confronted with an unfamiliar bird.

To make room for all the additional species, the new edition is larger than past editions, almost the size of the Sibley guide. The size and weight may make it cumbersome for field use. It all depends on how much you are willing to carry and how you carry it.

Peterson 1947, Peterson 2008, and Sibley 2000

Advanced birders may not like some aspects of the guide. In particular, rare species are clearly delineated from common ones by placing them on their own pages at the end of a family section. This has clear advantages for beginners since it reduces the likelihood of mistaken identifications. For advanced birders, it has the disadvantage that you need to flip about two dozen pages to decide if the godwit in your scope is a Hudsonian or a Bar-tailed. The lack of in-flight illustrations for most songbirds will make some identifications more difficult. The depiction of incomplete or cutoff forms for some species is another potential drawback.

As I have written in the past, each field guide will work best for different people. The best thing is to compare a group in a bookstore (or at the guides' websites) to see which features you like best. The new Peterson guide has much to recommend it, especially to a birder who seeks an additional desk reference or supplement to a regional guide.

Roger Tory Peterson, Peterson Field Guide to the Birds of North America. New York: Houghton Mifflin, 2008.