American Birding Podcast



How We Identify Birds: The Backstory

A review by Don Jones

Peterson Reference Guide to Birding by Impression, by Kevin T. Karlson and Dale Rosselet

Houghton Mifflin Harcourt, 2015

286 pages, $30—hardcover

ABA Sales / Buteo Books 14456

Have you ever been birding with someone, a local expert or a tour guide, who almost seemed to identify a bird before it appeared? Maybe you were taking a walk at the local playa, and the individual in question identified those distant, tiny dark smudges as Semipalmated Sandpipers before you could even tell for sure that they were shorebirds. Maybe the setting was a May woodlot teeming with migrants, and you were impressed when your leader announced that the twitch of movement in the deep shadows behind that brush pile was a Swainson’s Warbler rather than the expected Ovenbird or Louisiana Waterthrush.

In either case, you knew how to identify the bird given sufficient time and a good view (two conditions that are all too often a luxury in the field), but you were left wondering how anybody could have possibly assigned a name based on that fleeting glimpse. It can be done, using the time-honored technique of “birding by impression,” a term used to describe the use of behavior, body size and shape, habitat, and a suite of other non-traditional field marks to identify a bird.

Ever since the birding community of North America consciously recognized the value of this approach, it has largely been the purview of the veteran birder, honed during countless thousands of hours spent in the field, and difficult to explain to newcomers. With the publication of Peterson Reference Guide to Birding by Impression by Kevin Karlson and Dale Rosselet, that is no longer the case. Birders of all experience levels will appreciate this book and learn from its concise layout, well-written text, and exemplary photographs.

The goal of Birding by Impression is simple: to codify, in straightforward terms, what exactly causes different species to make a unique impression when seen in the field. The book is organized in two sections: an introduction, in which the authors describe in broad terms their purpose and methods; and the species accounts, which occupy most of the pages and provide very detailed information about similarities and differences within taxonomic groups. The introduction features a “how to use this book” section, plus interesting tidbits on the history, the functionality, and even the psychology of birding by impression. Karlson and Rosselet describe the fundamental characteristics that contribute to the distinctive impression of any species of bird: size, shape and structure, behavior, plumage details, habitat use, and vocalizations.

This may strike you as simplistic; after all, I’m guessing we all know that Common Ravens are larger than American Crows, or that a Canada Goose is more likely to be found on fresh water than is a Brant. But the value of this book lies in its organization and presentation of already known information in a holistic, easily accessible format, ideal for quick scanning or thorough reference. The authors excel in using simple, commonsense language to describe a bird’s appearance; for example, in comparing yellowlegs, they write that the “Lesser’s gently rounded body contours, evenly balanced body structure, and shorter, more evenly proportioned neck and head differ from Greater’s rangy, angular body contours, longer neck with a prominent ‘Adam’s apple-like’ bulge on resting birds, and bulkier, front-heavy body structure.” I can’t think of a more accurate one-sentence portrayal of these tricky-to-ID birds!

One of my favorite things about Birding by Impression is its unique breadth of content. While I certainly haven’t read all the bird books out there, I cannot think of another title that covers this type of material across such a broad range of birds. Reading through the lengthy section on shorebirds, I was reminded of The Shorebird Guidewhich, incidentally, was co-authored by Karlson. While Birding by Impression covers groups of birds rather than individual species, and lacks the full-page photographs of The Shorebird Guide, it conveys the same type of information for all the major groupings of North American birds. This is huge: No longer do you have to sort through separate references for waterfowl, hawks, and hummingbirds. Rather, it’s now possible to access in-depth information about each family or other large grouping in a single compact volume.

Certainly, this book is no replacement for your tried-and-true field guide ; it’s called a reference guide for a reason, and is meant to be enjoyed from the comfort of an armchair after a long day of birding. That said, I was recently very happy to have it in my backpack when I chased a couple of swans that had been reported in a nearby town. Finding the birds was relatively easy, but assigning an ID was not. As usual, they were quite distant from the closest road, the wind was howling, and the fact that I was in Vermont meant that either species was noteworthy and range wasn’t particularly helpful. After reading the section on swans in Birding by Impression, I felt much more comfortable calling these birds Tundra Swans than I would have using only a standard field guide. When confronted with a male Painted Bunting, you are unlikely to need anything more than a simple illustration, but I always carry my copy of Birding by Impression for those cases where typical field marks don’t give you enough to make an ID. And becauseBirding by Impression isn’t some hulking coffee table book, it’s more practical to carry in the field than many other reference books. I would suggest that no other text so successfully bridges the divide between field guide and reference guide.

Although the layout and text of this book deserve the credit I’ve given them, it is the photographs that make Birding by Impression truly one of a kind. I’d argue that the volume is worth purchasing even if you never get around to actually reading it, because in a very real sense the entire thing is one big photo quiz. Of the 200+ photographs featured, almost half are “quiz photos,” which ask the reader to apply the information in the species accounts to an unidentified bird or birds in the photo. Several times, I was tempted to skip ahead and just try the quizzes; turns out I don’t know quite as much about female buntings as I thought I did! Every time, though, after reading the written entries I was able to identify the birds that had at first tricked me.

Being able to compare written pointers and visual examples on the same page is a large part of this book’s success in imparting knowledge otherwise learned only through long hours in the field. Furthermore, while there are plenty of full-frame shots of gorgeous warblers and hummingbirds, there are also quite a few, well, bad, photos, and I prefer these. Let’s face it, how often do you get a scope-filling view of a Semipalmated Sandpiper among a flock of Westerns? Much of the frustration many birders feel with “problem” birds (sandpipers, female hummingbirds, sparrows, etc.) arises from the reality that you just never seem to get good enough looks to see the field marks in the book. Karlson and Rosselet’s focus on the overall impression of a bird, which can be picked up from a much greater distance and under less than ideal viewing conditions, is greatly enhanced by photographs that accurately portray the kind of looks most of us get in the field.

If you’ve made it this far, you know that I’m a big fan of Birding by Impression. Kevin Karlson and Dale Rosselet, both experienced and respected birders, have created a resource that is accessible to beginners and informative for experts. They have managed to put into writing many details not typically found in a conventional field guide and have provided superb photographs as illustration. From the days of identification by shotgun, through the discovery of field marks, to the digital revolution allowing examination of individual feathers, the birding community has accumulated a vast body of understanding about the avian wonders we all cherish. Birding by Impression represents the apex of that knowledge; it is a reference guide to help birders master the art of not just seeing but knowing the birds they encounter. This volume has quickly worked its way onto my short list of bird books, and I’m confident that you’ll like it just as much.

– Don Jones is a senior at Middlebury College in Vermont, where he studies Conservation Biology. Growing up in Wyoming, he explored the astonishing natural landscape and came to enjoy birding. Jones hopes to put his interest in the environment and birds to good use as a professional wildlife biologist after graduation.

Recommended citation:

Jones, D. 2016. How We Identify Birds: The Backstory [a review of Peterson Reference Guide to Birding by Impression, by Kevin Karlson and Dale Rosselet]. Birding 48:64-65.