Common Gull - WHITE [EZ77] / black

Edit: confirmed as subspecies Larus canus heinei.

Russian Common gull (Larus canus heinei), adult
Leiden, The Netherlands, December 26, 2010. W[EZ77] (Arnhem 3690757). Adult Common Gull in full winter (basic) plumage. This indidivual was ringed earlier this year in Zoetermeer, just south of Leiden, and has apparently returned to the area. Based on measurements taken as well as interpretation of the mantle color, this individual has been identified as a Russian Common Gull.
(Ring info: January 8, 2010, Noordhovenseplas, Zoetermeer.)

Russische Stormmeeuw (Larus canus heinei), adult
Leiden, Zijl, 26 december 2010. W[EZ77] (Arnhem 3690757). Adulte Stormmeeuw in volledig winterkleed. Dit individu is eerder dit jaar geringd in Zoetermeer, en is kennelijk naar de regio teruggekeerd. Dit is individu is al Russische Stormmeeuw geidentificeerd op basis van opgenomen metingen en intepretatie van de kleur van de mantelveren.
(Ringdatum: 8 januari 2010, Noordhovenseplas, Zoetermeer.)