posted April 17th, 2012; last edited April 17th, 2012 –– David Sibley
Lesser Black-backed Gull
Photos of a distinctly dark-mantled adult Lesser Black-backed Gull, South Monomoy Island, MA, 18 Sep 2010. This bird appeared consistently darker than the several other Lesser Black-backed Gulls present, and was at least showing the characteristics of the subspecies intermedius, which is rare in North America. It also appeared smaller and slimmer than the other Lesser Black-backs present, and the wingtips seemed to be raised higher when swimming. Comments welcome.
Subject bird at back right, with two graellsii-type Lesser Black-backed in foreground and adult Great Black-backed at back left. Photo (c) David Sibley.
Three typical graellsii-type Lesser Black-backeds in foreground, one Herring Gull at right, Great Black-backed at the rear, and subject bird just in front of that. Photo (c) David Sibley.
Three typical graellsii-type Lesser Black-backeds in left foreground, one Herring Gull at right, Great Black-backed at the back right, and subject bird back center. Photo (c) David Sibley.
Subject bird just in front of the adult Great Black-backed (back), with three typical graellsii-type Lesser Black-backed and one Herring Gull. Photo (c) David Sibley.