ML154802041
Iceland Gull (Thayer's x Iceland) Larus glaucoides thayeri x glaucoides/kumlieni
Laguntzailea
Data
Kokapena
- Adina
- Zehaztu gabea
- Sexua
- Zehaztu gabea
Behaketaren xehetasunak
In this first image, note petite bill, gentle facial expression, and head shape, which favor kumlieni. Eye color appears dark in this image; other images show amber irides with brown flecking. Eye color is non-diagnostic in either case. In second image, note smooth pattern of streaking on head, nape, and neck-sides extending onto breast-sides. Mantle shade was indistinguishable from American Herring Gull by direct comparison; Kumlien's mantle normally slightly paler than smithsonianus and Thayer's often slightly darker. In third image, note broad white tertial crescent and gray (not slaty-black) on folded primaries. The double dot mark on P6 is unusual. In final image, note intermediate wing tip pattern which fits neither thayeri or kumlieni. Thayer's Gull normally shows slaty-black (not gray) pigment in wing tip, including a small mark on tip of P5, white tongue-tips on P6 and/or P7 and P8, white tongue-mirror on P9, and white mirror usually with a partial or complete subterminal blackish band on P10. Kumlien's Gull normally shows a white tongue-mirror on P9 extending across the outer vane to join a terminal white tip on P10, with no markings on the tips of either P5 or P10. The gray, incomplete subterminal band on this bird's P10 supports identification as an intergrade. The two gray dots near the tip of P6 are not typical of either taxon.
Informazio teknikoa
- Fitxategiaren tamaina originala
- 2.84 MB