Identification of American Herring Gull in a western European context

Identification of American Herring Gull in a western European context495051 5241 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,January 2001 (Pat Lonergan). Very distinctive individual. Note rather Glaucous Gull L hyperboreus-like demeanour andlack of any clear grey feathers in upperparts.42 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,January 2001 (Pat Lonergan). Note rather simple pattern on scapulars and tertials and lack of any barring in plumage apartfrom vermiculation on greater coverts; also, note diagnostic, practically solid-brown longest undertail-coverts.43 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,January 2001 (Pat Lonergan). As in plate 42, note simple pattern to scapulars with practically no barring. Unusually forsecond-winter, note dark bill.44 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,January 1998 (Pat Lonergan). Note extensive brown wash to underparts and dark tertials.45 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,February 1999 (Killian Mullarney). Note dark lower hindneck extending onto underparts and rather uniform tertials.46 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,February 1999 (Pat Lonergan)47 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Long Island, New York, USA,January 1992 (Pat Lonergan). Note rather greenish-toned bill, extensively dark tail and solid-brown undertail-coverts.48 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,February 1999 (Killian Mullarney). Note rather uniformly coloured tertials.49 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,January 1999 (Pat Lonergan). Very dark individual. Note very uniformly patterned undertail-coverts.50 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,February 1999 (Pat Lonergan). Conclusive identification of individuals looking like this bird, and perhaps the bird in plate52, would pose a challenge in Europe.51 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,January 2001 (Killian Mullarney). Note uniformly dark brown lower hindneck and upper mantle extending onto underparts,and tertials with limited pale markings.52 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, second-winter, Boston, Massachusetts, USA,January 1998 (Pat Lonergan). Lightly marked individual, not so different from some European Herring Gulls L argentatus.19