Birders talk a lot about wingbars — contrasting bands of pale markings across a bird’s folded wing. The presence or absence of wingbars is one of the first things we learn to look for when we are learning to identify birds, and it is extremely helpful to sort through a bunch of potential species quickly. Even the most experienced birders will still make comments like, “Well, it has wingbars, so it can only be species A or B.” But wingbars come in all shapes, sizes, and colors, and thinking of them simply in terms of presence or absence leaves out a lot of interesting and useful information.
Wingbars are formed by pale tips on the greater and median secondary coverts. The main wingbar — the longer one that goes across the middle of the folded wing — is formed by the tips of the greater secondary coverts, and the shorter wingbar farther forward involves the tips of the median coverts. This shorter one is often partially, and sometimes entirely, covered by the scapulars (from above) or the breast feathers (from below).
All songbirds have a similar wing structure, and the arrangement of greater coverts and median coverts is nearly identical on all of them — flycatcher, vireo, warbler, sparrow, etc. The colors and patterns of those feathers create the great variety of wingbars. The three species illustrated here all show obvious wingbars but with a lot of differences in details.
The American Goldfinch has broad and square-cut pale tips with solid dark bases on all its greater and median coverts, forming two neat, broad, and very contrasting bars.
The Fox Sparrow also has pale tips on all the coverts, but in its case, the pale tips are small, forming a string of dots rather than a solid bar, and the feathers have brownish edges, reducing the overall contrast.
On Northern Parula, the innermost greater coverts (toward the top of the folded wing) are entirely gray, and only the outer greater coverts have white tips, while the median coverts have large white tips. This makes the two wingbars about equal in size, which is an unusual pattern and can be useful to identify a parula quickly.
This is just a sample of the variety that can be seen in wingbars. Almost every species has its own distinctive pattern, and the finer details often vary by age, sex, and season. Take the time to look carefully at the wing coverts of some songbirds, and you will be rewarded with a whole range of intricate variation.
This column was published in the May/June 2022 issue of BirdWatching magazine.