Advanced Birding

by Mike Stiles

Last month we talked about beginning birding, and some of the basics you might need to know when you first start looking at birds. This month I will give you a taste of some aspects of advanced birding, what the experts look at in the field.

Many beginners become frustrated trying to identify certain groups of birds, and for good reason . . . they're hard. As you become more and more proficient at bird identification, it becomes time to try your hand at the difficult groups, such as the gulls, sparrows, winter sandpipers, fall-plumaged warblers, and the epitome of all challenges, the empidonax flycatchers.

The gulls are a good example. Gulls have a different plumage for each of the first four years of their lives--except for the gulls that only have three plumages. Heck, even gulls of the same species at the same age can vary. A gull might molt only the head and body feathers, while the unmolted wings will wear and fade in color. And to make matters worse, gulls species readily hybridize with each other, with the resulting bird showing characteristics of both parents.

To watch the experts scope through a large mixed-species flock of gulls, calling out most of them is quite impressive, and is the result of many years of study. The good thing is, gulls are easy to study, standing on the beach like they do. At least they're not flitting around in the top of a pine tree.

The empidonax genus—often shortened to empid—of which the Pacific-slope Flycatcher is the most common representative in our county, can be quite vexing, and I've even seen the experts leave them unidentified. Kenn Kaufman, in the Peterson Advanced Birding Guide states "if you feel you can identify every empidonax you see in the field, you are probably deluding yourself." They are best separated by their calls, but of course, when we see them here in central California in migration, they are mostly silent.

They are so similar in appearance that Kaufman says "there is often more variation within a species, than there is between any two species in the genus."  Things to look for are bill shape and how much of the underside of the lower mandible (if any) is dark, and if the primary projection (the length that the primary feathers extend beyond the secondary feathers) is long. Or short. Or somewhere in between. Of course "long" is a very subjective term when there is only one bird in view and nothing to compare it to.

Another aspect of advanced birding, and one that is becoming much more popular recently, is the identification of subspecies. The Song Sparrow, for example, occurs across the entire country, and is highly variable geographically in size, bill shape and coloration. Fox, Sage, and Savannah Sparrows also are highly variable, and several of the named subspecies can occur in one area.

One reason for this new-found interest in subspecies is the advent of DNA studies. If the scientists find enough genetic differences between subspecies, one or more forms may be raised to the species level. This, of course, will add another "tick" to our bird lists. Relatively recent splits have involved the Brown Towhee split into California and Canyon Towhees, the Plain Titmouse split into Oak and Juniper Titmouse, and the Island Scrub Jay split from the Western. The Fox and Savannah Sparrows (to name two) are currently being considered as splits into several different species.

Birders have some concern that this may be carried too far, especially in the case of the Red Crossbill. Preliminary genetic studies have shown that the crossbill may actually be eight different species, with traits so subtly different they will be inseparable in the field. Some of the named subspecies cannot be separated even in the hand, but are based on the types of pine cones they eat and the breeding range, both of which can change if the environmental conditions change.

So don't pass by the hard ones, but instead embrace them. Take the challenge and work on those difficult groups as you encounter them. Study the sparrows at your feeders, or the gulls on the beach. Find one you do know and study it well, so that you can recognize the differences when you see a slightly different one. Don't be afraid of the "little brown jobs."

Burrowing Owl on banner by Cleve Nash.