Maybe this lesson should be titled, "Why Doesn't the Bird I'm Trying to Identify Look like Any of the Pictures in My Bird Identification Guide Book and Why Did it Just Fly Away?" This lesson will not substitute for your bird identification guide but Iíll try to provide some hints on placing the bird into a group of similar species to make your chances of finding it in the book more realistic. We will also explore plumage variations due to age, season, wear, molt, light, etc.
There are two basic processes for bird identification. The first is to memorize the specific characteristics of each bird. For North America alone this would mean memorizing juvenile, winter, breeding, and male/female differences in plumage for more than 800 species. I estimate approximately 5000 characteristic combinations. This is a conservative estimate as some birds (gulls, for example) go through many juvenile plumage stages before reaching adulthood. For birders with a perfect photographic memory I recommend this process. However the memorization method is so foreign to my capabilities that I can't offer any suggestions for the original acquisition these images.
The second identification method involves a hierarchical process where only a few characteristics are memorized and the remaining steps involve looking in a bird identification guide and birding so frequently that some bird images and names become commonplace. With this method and an array of excellent bird guides one can identify bird species with regularity and just get better and better at birding as time passes. If you are like me, you only rely on your photographic memory for the most common species.
Step 1 -- Start with body size and shape, bill size and shape, leg length, and habitat characteristics to quickly place the observation in one of the following groups -- waterfowl, raptors, shorebirds, hummingbirds, woodpeckers, flycatchers, jay-like, warblers, sparrows/finches, blackbirds, other small passerine, or "I don't have a clue."
Step 2 -- Study bird identification books for overall group characteristics and go birding with friends. Often more experienced birders or trip leaders will quickly call out a bird name. Be aggressive. Ask fellow birders how they determined a species or knew what group the observation belonged in. With practice and asking questions you will understand hints like looking at the body and wing shape of raptors for identification clues. Look at body size, length of legs, behavior, and the shape and length of the bill for important characteristics of the shorebird group. For warblers look for color patterns, wing bars, and eye ring/streak. Identification of a specific sparrow may be difficult but the size, shape, and conical shape of the bill guides your observation to the sparrow/finch group.
Step 3 -- Carry and use one or more bird identification books. The second part of this step is to practice, practice, and practice. Remember, birding is a recreational and leisure activity so enjoy the experience even if you can't identify every bird you see. Satisfaction can be gained by just getting to the bird group of an observation.
Pete Dunne, world class birder, often writes and talks about "probability" birding. By knowing what to expect an expert birder will first identify a bird by it's general characteristics with the highest probability of occurrence. Then the birder will look for specific characteristics that eliminate it from the original impression. If no eliminating characteristics are seen, then the identification stands. Pete often uses specific probability statements for effect, like "that's an 82% Peregrine Falcon." I suggest that beginning birders don't just accept the first call of a more experienced birder. For example, I recently called out "MacGillivray's Warbler" when I saw a small fall warbler with a green-yellow body and a gray head (highest probability of occurrence). Carolyn said, "But itís got a yellow throat." Well, this is one of the characteristics that make the observation a Nashville Warbler.
Don't expect your birding companions to identify a bird you saw by only a few characteristics. Most experienced birders identify a bird by many impressions along with their expectations. Most difficult for me is when someone says, "I saw a bird with the following characteristicsÖ" and those characteristics don't match any bird normally found in the area or during the season in question. I usually say something like "great," but Iím thinking in terms of IIT (Interesting If True). A birder learns quickly not to doubt a reported identification as rare birds tend to show up in unexpected places. Many years ago my wife called out "Great Blue Heron" while looking at a dry, rocky slope in a dry canyon along the Front Range of Colorado. I said "fence post." It took some effort to turn around and go back but I soon found out it was definitely a Great Blue Heron.
I will now run through a few scenarios I use for identification. As many books have been written on bird identification this list is very limited but hopefully will provide a possible path that might lead to an identification.
Scenario #1: A fairly large raptor is flying overhead. The bird is soaring, has broad wings and spread tail. Therefore I think "buteo." Next, I look at the wing pattern as I know Red-tailed Hawks have a dark mark on the inner leading edge of the under wing and Swainson's Hawks have a bi-colored wing with light under wing lining and dark flight feathers. Third, I look at the tail and note it is reddish in color with no barring. As the bird is quite light on the belly (light morph), I look at the lower leg pattern to see if a reddish V image is apparent on the lower belly -- Ferruginous Hawks have this pattern. I call out "Red-tailed Hawk." In the Ogden area some birders quickly call out "Redtail" as about 90% of the buteo observations are redtails.
Scenario #2: A fellow birder calls out "Whatís that bird?" I ask "What bird?" I look at the top of a box elder tree where my birding companion is pointing his/her binoculars. In the best of all worlds, my birding buddy would say "Whatís that small yellow bird with a small pointed bill located just left of center at the top of the box elder tree?" Then we could both note that it has no black cap, no grayish head, no eye ring, no eye stripe and no wing bars. Then I would immediately answer "Yellow Warbler" and then look for orange streaking on the breast to determine if it was a male or female. In the real world I usually hear, "I see something yellow" and I don't see the bird until it flies to a nearby cottonwood tree. Occasionally I'm lucky enough to see it in the cottonwood tree, confirm my expectations and identify it as a Yellow Warbler.
Scenario #3: One of my birding friends (usually female) points to a brushy area and says that she hears a bird singing. Bird songs can be an excellent means of identifying an elusive species. My problem is that my old ears have lost their ability to pick up low volume and high frequency sounds. However, even a non-hearing experience provides hints to bird identification. I know I can hear brush-inhabiting birds like Yellow-breasted Chat, Black-headed Grosbeak, American Robin, Song Sparrow, etc. so I forget those species and ask questions about what the bird sounds like (all the time straining my eyes to see some movement). Songs are often a powerful clue as to the group of species the observation belongs to. In this scenario she describes the song as a wheeze and a series of insect-like buzzes. I immediately start looking for a Blue-gray Gnatcatcher as her song description eliminated many warblers and sparrows. We then both spot a small nervous gray bird with a long black tail and an eye-ring. Yes, itís a Blue-gray Gnatcatcher!
I'm often asked how to identify a bird after only seeing the south end view of a north flying bird or some quick movement in thick vegetation. I reply "if you need a name, just make up one as no one will argue." The best thing to do is just enjoy the birding experience. Thereís no need to have a name attached to every bird seen. Also, be quiet and patient and keep looking. Birds are very active and will often move to a more observable position or return to a favorite perch.