At first glance there doesn’t seem to be too much to help us identify this bird. Probably the first word that comes to mind is ‘drab’. But in a sense, the lack of much color is one clue. In spring when many birds are sporting their most vibrant color, a drab bird actually sticks out and narrows the field. In terms of plumage characteristics, the yellow streaking on the edges of the primaries and the tail feathers and the single white wing bar are the only colors that stand out in a sea of gray. The lack of any streaking on the breast eliminates Pine Siskins. But this is a bird where structure also helps. Although it might not be obvious from this photo, this bird is TINY, being noticeably smaller than the more numerous nearby sparrows, chickadees, nuthatches, and titmouse. Size matters, and is another clue that will point us toward the correct species. Two notable structural features are the seemingly oversized eye in a bulky head that for me immediately stood out upon the first binocular view, combined with an undersized delicate bill. When considering nearly all-gray eastern birds that are smaller than chickadees with tiny pointed bills, there are really only two options: Ruby-crowned and Golden-crowned Kinglets. The colored ‘crowns’ of kinglets are not always obvious, so we need to be able to identify them by other characteristics, and this bird lacks the black facial marks of the Golden-crowned. This is a Ruby-crowned Kinglet.
Two behavioral characteristics helped to identify this bird in the field. First, Ruby-crowned Kinglets are beginning to sing at this time of year as they prepare for their northward migration to their breeding grounds, and this bird was singing its long and lovely song. It is beneficial to acquaint yourself with this song before going out into the woods this time of year. Secondly, kinglets are very active feeders, and their hyper-active, constantly moving feeding activity was a big clue even before lifting the binoculars.