Sure, it’s great to look at feathers. But the “soft parts” of a bird—its eyes, bill, and feet—also provide essential ID cues.
The bird in this issue’s Featured Photo is instantly recognizable to many of us as one of the ABA Area’s two species of large mergansers in the genus Mergus. The bird’s color scheme—its rusty-brown head, extensively orange bill, and gray upper-parts—seals the deal. However, getting the ID to species—Red-breasted vs. Common—can be tricky. Various plumage features—the presence or absence of a white chin, the precise color of the head—may offer excellent clues to an individual merganser’s identity, but there’s more to Mergus ID than plumage. The more identification features there are in the birder’s tool box, the more likely that an identification will be certain and, more important, correct. I here proselytize for a set of features that are often overlooked: the color of the soft parts.
“Soft parts” is the term given to the parts of a bird not covered by feathers, although some of these parts are not particularly “soft.” For most species, the list is limited to the bill, eyes, and legs, but a sizable minority of birds have additional features such as orbital rings, bare facial skin, or even largely unfeathered heads.