glaucoides - kumlieni
(last update: January 26, 2012)
Kumlien's / Thayer's Gull (kumlieni / thayeri) adult, January 15 2012, Canal Park, Duluth, MN. Picture: Karl Bardon.
Age adult winter, lacking brown wash on primary coverts.
Wingtip darkness score: 3 - blackish grey (Estimated Kodak 14-17). In the study by Howell & Mactavish, about 5% of Kumlien's Gulls in New Foundland belong to this category, see Table 1.
Wingtip scoring for dark markings on P5-P10: 2-5-5-5-4-1. See Plate 1 for explanation.
Wingtip pattern category: Type Q, Stage 6; darker grey or more extensive grey marks on the outer six primaries with complete subterminal bands on three to four primaries among P6-P9. No complete match to this type, but Type Q closest especially as the primaries are pigmented really dark, blackish. See primary patterns for explanation. In the study by Howell & Mactavish, about 5% of Kumlien's Gulls in New Foundland belong to this category, see Table 2.
Iris colour -
Head profile and bill structurally fit Kumlien's, and the white mirror on P9 reaches the outer edge on the outer-web as in Kumlien's. But note the black dot on the outer-web of P5, and the dark blackish extending along the outer-web of P10 all the way to the primary coverts (more typical of Thayer's).
See als Karl Bardon's website.