KOMPANJE EJO & POST JNJ (1990) Eastern Common Gulls Larus canus heinei in The Netherlands and Western Europe. LIMOSA 63 (1): 2-6.

Two remarkably robust Common Gulls found along the coast of the province of Zuid-Holland, The Netherlands, Limosa 63 (1990) 1 in January and February 1987 were identified as Eastern Common Gulls Larus canus heinei on account of their high and long bills. A comparative biometrical study (tab. I) led to the conclusion that there is considerable overlap in values of standard measurements of the subspecies Larus canus and heinei. However, birds with a bill height over 11.8 mm ( 11.0 mm , and a wing length larger than 392 mm and 371 mm can be safely considered heinei (tab. 2). It appears quite likely that in the Netherlands and adjacent lowlands around the southern North Sea Eastern Common Gulls occur regularly between November and March. In order to obtain more precise information on the status of heinei in this area, it would be valuable to take measurements (particularly of the bill) of any large Common Gull found during autumn and winter. We have hardly any confidence in claimed occurrences of heinei based solely on sight records.Common Gull Larus canus canus Russian Common Gull Larus canus heinei

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