Identification of American Herring Gull in a western European context

Identification of American Herring Gull in a western European context323334 3524 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, first-winter, Boston, Massachusetts, USA, January1999 (Pat Lonergan). Rather similar to bird in plate 36 but with predominantly first-winter scapulars. Note pale head, contrastingwith uniformly dark colouration on lower hindneck, mantle and underparts.25 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, first-winter, Boston, Massachusetts, USA, January1999 (Pat Lonergan). Rather grey individual. Note absence of dark base to greater coverts and overall discontinuous pattern ofscapulars.26 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, first-winter, Boston, Massachusetts, USA, January2001 (Pat Lonergan). Note uniform, dark underparts and typically densely patterned vent and undertail-coverts.27 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, first-winter, Cobh, Cork, Ireland,8 January 2001 (Killian Mullarney). Note new, more slate-grey coloured feathers on flanks, contrasting with older, faded, brownishjuvenile feathers on belly.28 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, first-winter, Boston, Massachusetts, USA, January2001 (Pat Lonergan). Note uniformly dark colouration on lower hindneck continuing onto underparts and contrasting with palerhead; also, note strongly bicoloured bill.29 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, first-winter, Boston, Massachusetts, USA, January2001 (Pat Lonergan). Note uniformly dark upper mantle and base to hindneck, contributing to pale-headed appearance.30 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, first-winter, Boston, Massachusetts, USA, January2001 (Pat Lonergan). Very grey and plain individual.31 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, first-winter, Boston, Massachusetts, USA, January1998 (Pat Lonergan). On some first-winters, pale-blotched scapulars contrast strongly with rest of plumage; note also very worntertials and inner greater coverts, almost entirely lacking pale fringes.32 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, first-winter, Boston, Massachusetts, USA, January1998 (Pat Lonergan). On this individual, first-winter scapular pattern is very regular, reminiscent of typical European Herring GullLargentatus, but note uniformly dark hindneck, mantle and underparts, densely patterned vent and undertail-coverts.33 American Herring Gull / Amerikaanse Zilvermeeuw Larus smithsonianus, first-winter, Boston, Massachusetts, USA, February1999 (Pat Lonergan). Note distinctive rump and uppertail pattern, dark greater-covert bar and pale inner primary window.34 European Herring Gull / Zilvermeeuw Larus argentatus argenteus, first-winter, Cobh, Cork, Ireland, 3 January 2002 (KillianMullarney). Occasionally, European Herring Gulls can have more saturated and consequently darker-looking brownish-greyunderparts than usual. Note comparatively weak undertail-covert barring and hint of white in tail.35 European Herring Gull / Zilvermeeuw Larus argentatus argenteus, first-winter, Dublin, Ireland, 14 October 1998 (Killian Mullarney).Typical bird, exhibiting evenly barred pattern of fully-moulted first-winter scapulars. Note narrow dark bars on undertail-coverts.13