Appreciate the wing bars

Birders talk a lot about wingbars – contrasting bands of pale markings on a bird’s folded wing. The presence or absence of wingbars is one of the first things we learn to look for when learning to identify birds, and it’s extremely useful for quickly sorting through a bunch of potential species. Even the most experienced birders will continue to 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 just looking at them in terms of presence or absence leaves out a lot of interesting and useful information.

The wingbars are formed by pale tips on the greater and median secondary coverts. The main wingbar—the longer one that crosses 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 medial 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 almost identical on each of them – flycatcher, vireo, warbler, sparrow, etc. The colors and patterns of these feathers create the wide variety of wingbars. The three species shown here all show obvious wingbars but with many differences in detail.

American Goldfinch in non-breeding plumage has two broad wingbars. Art by David Sibley

The American Goldfinch has broad, square pale tips with solid dark bases on all of its upper and mid-coverts, forming two distinct, broad, high-contrast bars.

The Fox Sparrow also has pale tips on all coverts, but in its case the pale tips are small, forming a chain of points rather than a solid bar, and the feathers have brownish edges, reducing the overall contrast.

Fox Sparrow has a chain of pale dots rather than a solid bar. Art by David Sibley

On the Northern Parula, the innermost greater coverts (upward of the folded wing) are entirely grey, and only the outer greater coverts have white tips, while the medial coverts have large white tips. This makes the two wingbars roughly equal in size, which is an unusual pattern and can be useful for quickly identifying a parula.

This is just a sample of the variety that can be seen in the 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 closely at the wing covers of certain songbirds and you will be rewarded with a whole range of intricate variations.

This column was published in the May/June 2022 issue of BirdWatching magazine.