This month we’ve got an apparently small bird flying overhead. Perhaps-important ID clues include the mix of buff and white below, the small bill, and the long primary projection. The final of those characters suggests that our bird is an individual of a species that is either a long-distance migrant or a highly aerial one… or both. On average, long-distance migrant species have longer wings – most of which length is accounted for by the primaries – than do short-distance migrants or sedentary species. That is because longer, narrower wings are more efficient for extensive flight. The same holds true, at least in part, for aerialists. To throw a monkey wrench into the system, some species have relatively long wings – and the concomitant long primary projection – perhaps simply because the feature has NOT been selected AGAINST. As example, nuthatches, in general, are neither long-distance migrants nor aerialists, yet they have very long wings and primary projection.

Of course, our quiz bird’s underparts coloration and the lack of white in the short tail rules out all ABA-Area nuthatch species. Those long wings rule out most members of most ABA-Area passerine families, leaving relatively – and perhaps surprisingly – few options.