A Guide to the Guide
How To Make This Book Work For You
There is nothing particularly complicated about a guide to bird identification. All it is (or hopes to be) is a book that explains what to look for to distinguish one species from another. In addition, both directly and indirectly it tells you how to go about doing so. For this book to work for you, you don’t need to know any more than this. All you have to do is turn to the account of a species of interest. Read the text. Bring the information to bear in the field, or in the case of a bird you’ve already found and studied, compare the text to the details housed in your memory (or inscribed in your field notes) and see whether you have a match.
But if you want to maximize the potential of this book, and if you are the kind of person who is interested in the whys as much as the what and the how, then you are invited to keep reading. Certain principles govern the information provided here and the manner in which it is presented. If you understand these principles, this book will serve you better.
First, insofar as this book is designed to be a supplement, it is presumed that you already have one or more of the standard illustrated field guides to birds at your disposal. As they have been since the publication of the seminal Peterson field guide in 1934, a basic field guide is every birder’s primary resource when confronting an identification challenge. This book is meant to augment these primary guides by offering more information. It also strives to present information as naturally as possible by replicating the identification process used by an experienced birder: looking at the big picture first and sleuthing for details later.
Inexperienced birders commonly use field marks to jump-start an identification. Experienced birders use field marks to confirm it. For very understandable reasons, standard field guides are thematically allied to the jumpstart school. This guide is more wedded to process.
Don’t Keep an Open Mind
Even before they sight a bird, experienced birders are bringing their experience to bear. They know that birds are creatures of habit and habitats and that the nature of a habitat encourages certain species to be there and discourages the presence of others. For example, you would expect to find a Carolina Wren in a suburban, coastal community in New Jersey. You would not expect a Rock Wren, a bird common to arid, rocky slopes.
Also, experienced birders know that different bird species have defining ranges (Rock Wrens are western birds that are not found east of the prairies, so they are not likely to be found in New Jersey) and that a bird’s range is determined not only by geography but by seasons. The range of Rock Wren extends into southern British Columbia, southern Alberta, and southwestern Saskatchewan in the summer, but in the winter northern breeding members of this species retreat farther south. This species is not located in Canada in winter.
So when these birders go birding, their accumulated knowledge and experience enable them to predict which birds they are likely to encounter based on location, habitat, and time of year (among other clues). And because they are able to go into the field juggling fewer variables, the identification process is greatly simplified for them.
When a wrenlike bird pops up on a scree slope in June in the Rocky Mountain foothills just west of Calgary, Alberta, they can test a hypothesis— “Is it Rock Wren?” (the expected species)—rather than approach the problem by asking: “Now, which one of the nine species of wrens found in North America is this?” But, you may be saying, I’m not an experienced birder, so I cannot apply such a search engine to filter what I see. That is exactly the function of the introductory paragraph in each species account.
Identification Right Think
The introductory paragraph for each species provides a biographical backdrop. The elements include STATUS, DISTRIBUTION, HABITAT, COHABITANTS, and MOVEMENTS/MIGRATION. STATUS relates to the bird’s numeric abundance and condition of residency (whether it is a permanent resident, a summer or winter resident, a visitor, or a vagrant). You are likely to see birds that enjoy large populations and less likely to see those whose populations are small. The terms “common,” “uncommon,” and “rare” are most commonly used to describe a bird’s status. A “common” bird is one you are very likely to encounter; “uncommon” refers to the bird you might see, but perhaps another, similar (and perhaps more common) bird should also be considered as a candidate. “Rare” birds are the ones you have only a slim chance of encountering. If you encounter a bird that reseembles a rare species, your identification may well be correct, but you should approach the possibility with caution.
DISTRIBUTION defines the geeeeeographic area in which the bird is typically found. For some species, this remains fixed all year. For other species, distribution shifts seasonally. HABITAT describes the biological setting—climatic, topographical, and vegetative—that the species favors and offers examples of such settings. COHABITANTS are the other birds (or animals) that are also specialized for and likely to be found in a bird’s preferred habitat. MOVEMENTS/MIGRATION provides the dates (and sometimes the routes and key staging areas) a species moves between its breeding and wintering areas; this passage sometimes carries the bird across regions that do not fall within that species’ breeding or winter range.
Taken in sum, STATUS, DISTRIBUTION, HABITAT, COHABITANTS, and MOVEMENTS/ MIGRATION constitute the biological framework that defines where a bird is likely to be and when it is likely to be there—and thus whether a species is likely to be what you believe it to be.
In a word, these elements of species’ biographical backdrop define probability. Experienced birders use probability all the time, and inexperienced birders eventually come to appreciate it. They also come to understand that probability is not confining and in fact is empowering. It helps turn a complicated question (“Now, which one of the 800 species of birds found in North America is that?”) into a simple one (“Is this the species I expect?”).
You’re in Cape May Point, New Jersey. You see a large wren in a suburban yard. The question you’ll ask is: Is it Carolina Wren, the default large wren for the region? Almost always the answer is yes. But as salient a factor as probability is, it is not determining. It suggests, but it doesn’t certify. Probability has a qualifying companion called possibility. Birds don’t always follow the rules. They sometimes turn up outside their prescribed ranges and in marginal or ill-suited habitats or at odd times. Getting back to the aforementioned Rock Wren, it so happens that in December 1992 a Rock Wren was found in Cape May Point, New Jersey, rummaging around in the scattered debris of a house under construction.
So the last piece of information imparted in the opening paragraph, designated VI—short for VAGRANCY INDEX—is a conditional modifier. This index relates to the known vagrancy tendencies of a species or the possibility that it may turn up where it doesn’t belong (in terms of its normal geographic distribution). There are five ratings.
0 No pattern of vagrancy. The chances of this species being seen outside its range are scant to nil.
1 Some slight tendency to wander, but such occurrences are regional, extending not far beyond the established borders of the species’ range, or there are simply very few records of vagrancy.
2 The species shows some modest pattern of vagrancy. It is possible to encounter it outside its normal range but still not likely, and you should consider other, more likely possibilities first.
3 This species has demonstrated an established, widespread pattern of vagrancy. Ignore the range descriptions. This bird could be sighted almost anywhere.
4 The species is so widespread that there are few places left in North America for it to wander.
If you don’t care to remember the particulars, just remember the rating system. The lower the number, the less likely a species is to wander.
Birds Are the Sum of Their Parts (and More), or, But How Did You Know It Was a Wren and Not a Swan?
The field marks used to differentiate birds relate most often to structure and plumage. Used in concert to make an identification, both are important. But a bird’s structural characteristics are in many ways more fundamental and more determining. More than plumage, structural attributes (such as bill shape, neck length, body shape, leg length, or foot shape) link birds to closely related species; also, because these attributes vary less between the ages and sexes within a species, they are commonly not as variable or transitional as plumage. Accordingly, the description for every species looks first at structure and concludes with plumage, focusing first upon the most fundamental traits.
SIZE AND OVERALL SHAPE: Birders argue as to whether size or shape is a bird’s most determining characteristic (the one experienced birders note first when making an identification). The fact is that most birders see and assess these qualities simultaneously, thus quickly simplifying the identification process.
STRUCTURAL CHARACTERISTICS: Bill size, shape, and length, head size and shape, the contours of a bird’s neck, the shape of its body, the length of its legs, the shape of its feet—all constitute important, determining structural characteristics. These morphological traits divide birds into groups, such as sandpipers, hawks, gulls, warblers, or finches. Placing a bird in the right group is the next major step in the identification process. The rest comes down to details—those related to gradations in structure (like the small differences in the bill structure between Western, Semipalmated, and Least Sandpipers) and those relating to plumage.
PLUMAGE: Once size, shape, and structural components have been noted, identification is often a simple matter of making a determination between two (or three) similar species. This is the stage in the identification process where plumage is often most useful. Some plumage-related traits (field marks) are blatant (such as the all-red plumage of a breeding male Summer Tanager or the unique and colorful pattern of a male Harlequin Duck). Some are more subtle but no less determining (such as the lime green back of a nonbreeding Chestnut-sided Warbler). But the plumage characteristics of many birds are not so singular and are shared to some degree by closely related species (for example, the plumage of female Bluewinged, Cinnamon, and Green-winged Teals). In this case it is necessary to use a combination of plumage (and anatomical) traits to differentiate the birds.
And then there are birds that so very closely resemble related species that the similarities are commanding and the differences subtle. When dealing with species such as Dusky and Gray Flycatchers, you often have no alternative but to pay attention to fine details of plumage and structure. But there are additional clues that may build a case for one species and parry away the possibility of another. Many of these relate to behavior.
Before focusing on behavior, let’s return to the beginning of this section, where I skipped a subjective but important element in the identification process. Birds are more than a bunch of isolated and idiosyncratic field marks.
They are living entities. They are the sum of their parts, and they project qualities that are in concert with what they are. Birds often look different or behave differently because they are different.
It’s easy to tell a wren from a swan. But telling Tundra Swan from Trumpeter Swan is more troublesome. You can look at the bill and try to catch a yellow spot on the base (a characteristic often seen on Tundra Swan) or the narrow, orange line that defines the gape of Trumpeter. Or you can look at the whole bird and determine whether it looks lithe (with its head erect), which is typical of Tundra Swan, or tired and slouched (with its neck couched or folded back onto the neck), which is the posture commonly adopted by Trumpeter Swan. Birders have a term for this projection of posture or sense of shape: GISS (General Impression of Size and Structure, pronounced gizz or jizz). GISS is a subjective clue, and its primary usefulness is to alert birders to the possibility that a bird is different or unexpected. It can also be very useful to the birder studying a bird at such a distance that classic field marks relating to plumage and shape are difficult to discern.
In the nickname or introductory tag line for each species, and often in a sentence introducing the species description, I have tried to capture something of the bird’s essence or gestalt. It is not as determining as a field mark, but it is often suggestive and sometimes commanding.
BEHAVIOR: The inherent shortfall with most field guides is that they treat identification as a static process. They depict birds in a fixed posture, with distinguishing field marks shown to best effect. The reality is very different. Bird identification is in fact a dynamic process. Birds are animate. They move and assume different postures, often treating observers to views that are not replicated in guides and demonstrating mannerisms that are difficult or impossible to get across in a photo or illustration.
Behavior can be as determining as structure and plumage in differentiating birds, both between species groups and between individual species— even (and maybe particularly) in differentiating some that are very similar.
Plovers walk, stop, and pick (like robins); sandpipers feed on the run.
Semipalmated Sandpiper likes to keep its feet wet; Least Sandpiper more commonly forages on damp (even dry) ground, away from the water’s edge (particularly when this smallest of sandpipers is feeding with other small sandpipers).
Band-rumped Storm-Petrels tend to be more skittish than Wilson’s Storm-Petrels. When flocks sitting on the water are approached, the Bandrumped usually flushes first. Tennessee Warbler is usually a canopy species (particularly in spring); the similar Orange-crowned Warbler most commonly feeds lower (often in weedy tangles). Gray Flycatcher is a compulsive tail wagger; the tail of Dusky is given to the occasional jerk but is not habitually wagged with a downward pump.
FLIGHT: The bird behavior that our own species finds most captivating is also one that is most challenging to the birder. Flight is the characteristic that more than any other defines birds. The ability to move through the air is not unique to birds (and in fact is not even practiced by all birds), but it’s the trait that garners both our attention and our envy. Thus, it is somewhat surprising that our ability to identify birds in flight and our means of describing them lag so far behind our ability to identify birds that are standing, swimming, or perching.
This is not true of all birds, of course. The flight profiles and styles of some birds (most notably hawks and seabirds) have been carefully studied for years, and field marks that work in this challenging arena have been codified.
Each species account in this book describes the bird in flight. Some of these descriptions are cursory, and others are more detailed.
In attempting to describe birds in flight, I found that I needed to differentiate between terms that are often used interchangeably in everyday usage. As you read the species accounts, it will be helpful to understand how I use the following terms:
STRAIGHT FLIGHT: The bird moves forward without deviating from its course. Example: American Crow.
WANDERING OR TACKING: The bird angles left, then right, then left. Example: Northern Flicker or Say’s Phoebe.
YAWING OR TWISTY-TURNY: The bird flies straight but not on an even keel—that is, it lists or favors one side, then leans to the other side. Example: American Woodcock.
UNDULATING: There is a regular and even rise and fall to the bird’s flight. Example: many woodpeckers.
BOUNCY OR BOUNDING: There is a regular, mostly even, rise and fall to the bird’s flight, with deep oscillations. Example: American Goldfinch.
JERKY: Bird flight characterized by abrupt, often irregular, bounce. Example: many warbler species.
RISE AND FALL: The bird changes its elevation—flying slightly higher, then dropping lower—but its flight is generally straight, and these altitudinal shifts do not show an even, undulating pattern. Example: Common Grackle or Baltimore and Bullock’s Orioles.
REGULAR OR STEADY WING BEAT: The bird moves its wings in a steady, unbroken rhythm. Example: American Crow.
IRREGULAR WING BEAT: The bird moves its wings in a halting or broken rhythm: Example: Belted Kingfisher.
FLAP AND GLIDE, OR A SERIES OF FLAPS FOLLOWED BY A GLIDE: The bird’s flight consists of a series of wingbeats punctuated by pauses lengthy enough to note that the bird is continuing to move forward. Example: Sharp-shinned Hawk.
OPEN-WINGED GLIDE: The bird glides with wings open and fanned. Example: Sharp-shinned Hawk.
CLOSE-WINGED GLIDE: The bird glides with wings closed and pressed to the side. Example: grackles.
SKIP/PAUSE: The bird flies with a momentary break in the rhythm (usually with wings closed) that is too terse to be called a glide. Example: many warblers.
I should point out that many birds alter their manner of flight according to conditions, objectives, and distance traveled. For example, sparrows (among many other species) flying short distances are frequently bouncy, but the same birds covering greater distance may be undulating or show a less energetic rise and fall. Birds flying downhill may glide extensively but then flap almost continuously, of necessity, when flying uphill. Birds heading into a wind will flap more (and glide less) than birds flying with a light tail wind. Courting birds exhibit all manner of energetic acrobatics that they never resort to when their objective is locomotion, not procreation.
Despite these variables, the flight of most species is fairly consistent, and while not necessarily defining, it can be an important aid to identification. The fact is that many birds are seen mostly in flight (such as many pelagic species), and some are most easily distinguished in flight. Flight identification is one of birding’s frontiers. Here’s another.
VOCALIZATIONS: Next to flight, song is the expression that best characterizes birds (and endears them to us). Many birds are easily and best identified by their songs, and not a few by their calls. And although most birds sing for only a portion of the year (just before and while they are nesting), some sing all year, and most make some identifying vocalizations or calls even in winter.
I was tempted to start each description of vocalizations with calls, the short utterances that both sexes make all year as opposed to songs, the more elaborate and lengthier vocalizations uttered mostly by males before and during nesting. In the end I sided with convention. I describe songs first (because they are, for the most part, more recognizable than calls), calls next, and then, if I was familiar with them or information was available, the flight calls of species.
PERTINENT PARTICULARS: Many of the species accounts conclude with “pertinent particulars,” which sometimes summarize key points, sometimes compare similar species, and sometimes offer a tidbit related to the finding or identifying of a bird. Using this vehicle, there are two very pertinent particulars I want to bring to your attention. Both relate to how these species descriptions will serve you.
Since the capacity to describe sound is directly related to a person’s ability to perceive it, I had my hearing tested at the beginning of this project and learned (as I have long suspected) that I am deficient in the upper middle range. My hearing is average for low tones, the lower-middle range, and very high tones, but at 4,000 Hz I am nearly 50 percent deficient in my left ear and 20 percent deficient in the right. What this means is that it is harder for me to hear sounds within this range than an average person, that very probably I miss (or mishear) notes in this frequency, and that my descriptions of bird songs will reflect this deficiency. (On the other hand, if you misspent your youth hanging around loud machinery and shooting trap without ear protection, as I did, then these descriptions are made to order.) Second point: My sensitivity to color is acute. (Yes, I also had my vision tested.) As evidence, when I look through a wide assortment of binocular makes and models, I note on many a pink (or green or yellow) color bias, the byproduct of certain lens coatings. When I see the heads of male scaup, I have no difficulty perceiving purple or green (or determining which is dominant).
When I see and describe white, I note a great difference between white and bright white. Here again, my senses (in this case a heightened one) affect not only my perceptions but my descriptions. Again, adjust accordingly.
Footnote on Field Guides
Insofar as this book is designed to be a companion to one or more of the very fine field guides that are available, in humility and deference I would like to offer readers my own thoughts about several popular guides. If you care to regard my comments as an endorsement, please feel free. If you conclude that my failure to discuss other guides constitutes a lack of regard for them, I wouldn’t so presume.
As stated earlier, this project was initially conceived as a companion guide for Roger Tory Peterson’s Eastern Birds (now also Western Birds, which is being revised). Both of Roger’s guides have a proven track record. Both are celebrated for their compelling simplicity and the empathetic accord between the text and illustrations (because the author and the artist were one). Roger’s approach to identification was anchored in the formative age of birding when everything relating to field identification was new. In the same way embryos pass through developmental stages that replicate the evolutionary advance of life on Earth (more accurately, life in the sea), all beginning birders must also begin with and pass through basic developmental stages before moving on to greater proficiency.Written on the most basic level, the Peterson Field Guides are easy for beginners to use.
The venerable “Golden Guide,” or Birds of North America, by Chandler S. Robbins, Bertel Bruun, and Herbert S. Zim, remains a utilitarian masterpiece, best recognized for the simple brevity of its text and the illustrations by Arthur Singer. Although this guide seems to have fallen out of favor with birders in the inner circle, the partiality shown it by bird watchers who do not consider the label “birder” fundamental to their identity or other birders the cornerstone of their social network is impressive and can only be attributed to the book’s continued merit.
The National Geographic Field Guide to the Birds of North America, now in its fourth edition, is a birding hallmark. It is celebrated for its thoroughness— in its scope, attention to detail, and focus on regional forms (subspecies). Virtually every species that has been recorded in North America is depicted (and thus many birders in Alaska, birders along the Mexican border, and pelagic birders on both coasts consider this guide their book of first resort). In addition, its studied focus on regional forms enhances the book’s value especially in the West, where multiple subspecies are more often encountered. For the sake of accuracy, the text does use more technical and less generic terms than some guides (including this one), and presentation can rarely be seamless when multiple authors and artists are employed. Despite these minor concerns, this is a great field guide and one that I have found immensely useful for more than twenty years, both as a first and last resort.
The Kaufman Field Guide to Birds of North America is wonderful— intelligently conceived and carefully executed. What Kenn has done, through brilliance and conscious design, is to craft a Peterson Field Guide for this age. The text is not just simple and precise, but evocative. It doesn’t just build an identification, but crafts an image of a living bird that can be carried into the field. It uses well-chosen photos organized in a way that facilitates comparison (an inherent shortfall of many other photo guides). I used this guide extensively during my travels (for pleasure as much as edification) and usually had it open to the appropriate page when writing my own descriptions in this book. Few birders (and certainly no beginning birders) should be without this guide. If you can own only two guides (because it’s impossible to own just one), make this one of them.
In every generation there is someone who dominates his field. When it comes to knowledge concerning the identification of North American birds, few can stand on the same platform with David Sibley. But when it comes down to recasting the world of birds in a field guide, none have done it so brilliantly and completely as David has done in his Sibley Guide to Birds. This guide is a symbiotic fusion of illustrations that are unsurpassed in their accuracy and supportive text that is precise, groundbreaking, and spare—a layout that is comparative genius. The book may fall short in only one respect. Artists think visually. When they depict something, they assume that people will perceive it. Sometimes they do not. At times during my studies I discovered some characteristics relating to structure or plumage or posture that I thought served to distinguish a species, and when I turned to David’s guide I found it depicted (David’s eyes miss little and his eye is in direct communication with his brush) but unsanctified by supporting text.
Still and all, no book published in this century (and only one in the last) has been so catalytic a tool for bird identification. If you spend part of your life studying birds, you cannot be without the Sibley Guide.
And since you have read, to this point, a great deal of text dedicated to these ambitions, I must conclude that you are, like me, a serious birder who strives to be a more accomplished birder.
Copyright © 2006 by Pete Dunne. Reprinted with permission by Houghton Mifflin Company.