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Coordinators: 1cy June 2cy Jan 3cy Jan adult Jan |
Ring-billed Gull delawarensis 2nd cycle (3CY), February 16 2014, BP Whiting refinery, IN. Picture: Maarten van Kleinwee.Obvious vestiges of immaturity: black in tail, black on central tertial, black on coverts. Note dull greenish yellow bare part coloration and lack of obvious white tips on outer primaries. Also, the mirror on P10 is often relatively small in 2nd cycle.
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delawarensis Ring-billed Gull