WAYNE R. PETERSEN

This issue’s mystery bird is a football-shaped, slim-necked, bubble-headed, swimming waterbird. Although size can often be difficult to judge from a photograph, especially one that offers nothing for comparison, the impression of the pictured bird is that it is not very large. When the list of options is thoughtfully considered, some of the more viable identification possibilities include ducks, loons, grebes, cormorants, and coots. Other waterbirds that swim, including petrels, shearwaters, storm-petrels, rails, phalaropes, and alcids, can readily be eliminated because of shape, pattern, coloration, or a combination of these traits.