Over the past 25 years, an embarrassment of riches has become available for the education of birders.  Dick Walton and Bob Lawson’s Birding by Ear tapes and now CD’s allowed birders to make huge leaps in the ability to identify birds by ear.  David Sibley’s 2000 book, The Sibley Guide to Birds took the field guide to a new level.  More specialized books on the identification of difficult groups like gulls, sparrows, shorebirds and hawks have enriched our libraries in the past decade.

The latest major contribution to bird identification is The Crossley Guide: Eastern Birds written and assembled by Richard Crossley.  The assembly I refer to is made possible by the ease with which one can manipulate digital images.  In this book, Crossley presents 10,000 pictures of the birds of eastern North America.

The bulk of the book is 640 plates, each devoted to a single species, in which Crossley pastes in photographs of the species over a photograph of the habitat of the species.  The composite plate is not intended to try to create the illusion of a single photograph but rather is an effective way to associate bird with habitat.

Some of the photographs are close-ups while others are more distant.  Sometimes side views are shown and in other cases back or front views.  Some birds are perched and some are flying.  Different plumages by age and sex are provided.

As an example, the Peregrine Falcon plate has an urban landscape with skyscrapers for the background (Peregrines do well in New York City and other metropolises with a near endless supply of pigeons to feed on).  Superimposed on the background are 15 photos of Peregrines.  One is in a stoop (watch out, pigeons!), one is flying directly toward you, and one is just a distant silhouette.  Perched adult and juvenile falcons are shown.  In short, you see Peregrines from many angles and distances, just like you would in the field.

I know an ornithologist from Washington state who holds that to really be proficient at field identification of birds, you must be able to identify a bird from five angles: from the front, from the back, from the side, from the underside in flight and from the upperside in flight.  Crossley’s book has all of these views for some of the species he covers.

The geographic scope covers eastern North America westward through the Great Plains.  The coverage ends at about the western boundary of Oklahoma, Kansas, Nebraska, the Dakotas and Saskatchewan.  The coverage of the species in this guide is exhaustive.  In addition to the common birds like Northern Cardinal, full coverage is given to eastern vagrants like Swainson’s Hawk, Sage Thrasher and Green-tailed Towhee and to ultra-rarities like Fieldfare, White-throated Thrush and Yellow-faced Grassquit.

The many images provide a rich resource for even the most seasoned birders.  My wife pointed out the red lores of a Snowy Egret in one of the photographs.  This color appears briefly early in the breeding season.  I had never seen this feature nor even been aware of it.

The plate takes up the bulk of the space for each species.  A small distribution map and telegraphic text on behavior and identification are provided as well.  Crossley also gives the four-letter code for each species that bird banders use.  As a bander, I have used these codes for years for efficient note-taking.

The vast majority of photographs are crisp and pleasing; some are truly stunning.  I am glad that the format of the book is large enough to ensure that details can be seen in the photographs.  I own other bird and insect photographic guides where the images are so small as to be nearly unusable.

The beginning of the book has the usual information on bird topography and molting.  Crossley also describes his idiosyncratic (to me, anyway) of identifying birds.  In order of importance, he lists these key features: shape, size, behavior, probability (is the presumed species expected here at this time of year?), color and finally voice.  I elevate the importance of voice to near the top of my list but it is interesting to read Crossley’s reasons for ranking the features.  To facilitate size comparisons, Crossley has photographs at the same scale of birds of each group at the beginning.  It is easy to see how much larger a Purple Martin is than a Bank Swallow.

Measuring seven by ten inches, this wonderful guide will be difficult to carry in the field.  Keep it in your car or backpack though.  This guide is a wonderful addition to the birding literature.

[First published on March 6, 2011]