Identification of birds plumaged between Thayer’s and Iceland Gulls has always created debate. Some treat the kumlieni-gulls as a subspecies of Iceland gull, and some mean it is a hybrid between Thayer’s and Iceland Gulls.
North-American based Steve Hampton just published a webpage with a suggested key that can be used to get an indication on what to label individual Thayer’s, kumlien’s and Iceland Gulls in their first winter plumage. The key is based on rating different parts of the birds plumage and bare parts, ending up with a total score which is used for identification. This is the first update, and the author wants comments and feedback to further refine the scales.
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