WAYNE R. PETERSEN

This month’s puzzler has the look of a “warbler-type thing,” a group of species that many birders know and love. The dark side to this story is that the mystery bird might be in nonbreeding plumage—a caveat that makes identification of many such species especially challenging.

Let us methodically focus our identification efforts by concentrating on obvious or distinctive field marks. Does the bird appear to have wing bars? Does it have streaks on its underparts, flanks, or undertail coverts? The answer appears to be no to all these possibilities. Furthermore, does the head, crown, or face show any distinctive pattern or markings? Apart from a fairly thin, whitish eyebrow stripe that barely extends behind the eye, the bird’s head does not offer any conspicuous clues. The mystery bird appears to be notably plain, not just on the wings and underparts, but also on the head and face—areas on many species that usually provide helpful clues for identification. In essence, we are left with a nondescript bird that is practically without pattern. This fact, however, is important in unraveling the identity of this month’s mystery species. As usual, readers are encouraged to view the photograph of the mystery species on the Bird Observer website. In color the bird appears uniformly light olive on the back and wings, with a very subtle hint of light yellowish on its flanks and with otherwise unmarked underparts.