Stephen IngrahamThe concept of field marks captures the imagination and the attention of many new birders. You look at the illustrations in the field guides with their little arrows--you read the text for the highlighted items. "Hey, look at this: you just memorize these few points about each bird and you got it, right?"
Well, not exactly.
In fact, an exclusive emphasis on the marks will leave you grasping for many an easy identification. I see beginners in the field all the time with their books out comparing wing bars, or the width of the crest markings, or the exact shade of the lores--when they aren't yet certain whether the bird is a vireo or a warbler, a finch or a sparrow, a flycatcher or a thrush. It may not be kind, but I call those unhappy novices "field marks." They have been taken and taken good.
Field marks (the technique now, not the people) are wonderful when it comes to differentiating very similar species. Indeed, writers in publications like Birding (the journal of the American Birding Association) are continuously introducing new marks, based on the most recent field studies, that allow the positive (or at least more certain) identification of very difficult species.
Field marks are not, however, the place for the beginner to begin. You could (and should) become quite expert at field identification without knowing a single one.
These are the things you need to know before you even begin to think about field marks:
This is simple to learn. You take a bird from each family that is found in your area and become thoroughly familiar with it. Pick an easy one: an Eastern Phoebe or a wood pewee to represent all flycatchers; a robin for the thrushes; a Brown Thrasher or catbird or mockingbird for the mimic thrushes (a.k.a. "thrashers"); a Red-winged Blackbird or Northern Oriole for the blackbird and oriole mob; a Yellow-rumped Warbler for the wood warblers; etc. Look at the pictures in your field guide until you sort out what makes all the warblers look like the Yellow-rumped, and all the thrashers like a mockingbird. If you are the type who needs to have such things formulated, get a notebook and write out a description of each family. It doesn't have to be all that conscious though. Many of us simply internalize the characteristics of the families without, as they say, giving it a second thought. "Ah, that's a flycatcher!" "Why do you say that?" "Well it looks just like the Say's Phoebe that nests on the porch." Got to be.
Within some families you can refine your focus a bit more by picking a typical member of groups of closely related siblings. The Chipping Sparrow is typical of the spizella cluster. I always take the Song Sparrow as a starting point for the group that includes the Lincoln and the Swamp (into which, for whatever reason, I lump the Vesper and the Savannah).
For the linear thinkers among you, here is what to look for when sorting families:
It should be obvious that one of the first considerations in any identification should be: "Could I really be seeing that? Here? Now?" Study the range maps in your field guide carefully. Go through and mentally note the birds of your area for each season. (Again, if you are the type, make yourself a list.) I do this periodically, just to sharpen my wits. Starting at the front of the book, I look at each range map. When I find a bird that might be here now, especially one I have never or seldom seen, I take a good look at the illustration and read the description. It takes a few days of leisure time to work through the guide, but I always come up refreshed and eager to get into the field. (What is more, you would not believe the number of times I have seen a bird I just studied within the next few weeks, or even days--just as though someone, somewhere, was rewarding my effort or something.)
Certainly, especially if you bird a lot, you will see birds that, in fact, should not be here now--but they are the rare exception, and when you see them, at least you won't confuse them with the birds that should be.
This information is harder to dig out of the guides. It is there, but it is often, as they say, buried in the fine print. I know of no actual field guide that even goes so far as to consistently put the information in the same place in the description (and "Why not!" I ask. Get with it guide editors! The three volume Audubon Master Guides to Birding have habitat information consistently and concisely placed right at the beginning of each description, but you are not likely to carry them into the field with you. Even then there is no heading: Habitat, and there ought to be. An excellent resource here, though again, not a field guide, is the Birders Handbook . If you don't own a copy, go buy one! Not only is the info there, but for those of us who get into such things, it is ideographically displayed--or is that iconographically--little stylized pictures, however you say it.). You are more likely to learn habitat preference by actually being out in the field in each of the different kinds in your area. Keep your eyes open.
As you might have guessed, you can spend a good deal of time and energy mastering the three areas above. Take heart. You could not spend yourself in a better way. This is not a liner process. As you are studying each of the three areas above you will be continuously gathering information that will fill out the other areas. What is more, you will not be able to help picking up a few actual field marks. Once you know a sparrow from a finch, you will want to know one sparrow from another. Again, my advice would be to focus on the general characteristics of the bird (see the list under sorting families), seasonal range, habitat, and characteristic behavior patterns before I put a lot of time into studying field marks. Why? All of the larger characteristics are easier to see, especially at a distance, than most of the field marks you will find listed in your guide. For a field mark to be useful, most of the time, you have to get a very good view of the bird, and you have to have time to observe it in detail. Nine tenths of the time you will have (or should have) made your identification long before you ever get close enough to see many of the field marks commonly listed or pictured in field guides--that, or the bird will already have flown away!
A final word: when you do get to the point where you are attempting the identifications that actually hinge on field marks, you will find most of the marks in your average field guide are inadequate anyway. By then you will need Kenn Kaufman's Field Guide to Advanced Birding , and the articles in the latest birding publications. But that, as they say, is a whole other story.
For now, study the big stuff, and don't let anyone make you into a field mark!