Black-tailed Gull (crassirostris) / ウミネコ / 괭이갈매기
(last update: December 2015)
Black-tailed Gull (crassirostris) sub-adult January - March
Birds in 3rd cycle plumage or birds which are difficult to age exactly but show at least some features that indicate immaturity. Ageing can be difficult and birds are therefore grouped as "sub-adults".
GULLS OF THE AMERICAS - The Peterson Reference Guides
- Steve N.G. Howell / Jon Dunn -
Below is a copy of chapter 21 about Black-tailed Gull, illustrated with images from this website. "we" in the text below refers to the original authors. If any errors occur in this text, please let me know and mail to marsmuusseatgmaildotcom.
LENGTH 17-20 IN. (43-51 CM)
This medium-sized four-cycle gull of ne. Asia is a vagrant to N. America, with records scattered from Alaska to Belize. Bill relatively long and parallel-edged with slight to moderate gonydeal expansion. At rest, tail tip falls at or slightly beyond tip of P6, so wing projection relatively long. Adult has slaty gray upperparts (Kodak 8-9.5) with black wingtips (lacking white mirrors), broad black subterminal tail band, and, in basic plumage, fairly diffuse dusky head and hindneck streaking. Juvenile dark brown overall with mostly blackish tail. PA1 variable, starting Sept.-Oct. Subsequent ages variable in appearance. First cycle has flesh pink legs becoming yellow by adult cycle; adult eyes pale lemon, orbital ring red.
Medium size, slaty gray upperparts, broad black subterminal tail band, pale eyes, yellowish legs, and black bill ring with red tip are a distinctive combination among adults of New World gulls. Mostly dark brown and dark-tailed first cycle told from California Gull by longer bill and contrasting white uppertail coverts. In S. America, Belcher’s and Olrog’s Gulls larger with blacker upperparts. See Similar Species section for more detailed identification criteria.
STATUS AND DISTRIBUTION
Coasts of ne. Asia, vagrant to N. America.
Nonbreeding. Casual visitor to w. Alaska (late May-mid-July) and s.-coastal and se. Alaska (mid-June-Oct.), exceptionally (Aug.-Jan.) along Pacific Coast to B.C., Wash., Calif. (notes 2,3,4,5) and Sonora, Mex. (June) (note 6). Casual in interior N. America from N.T. east to w. Great Lakes (June-July) (notes 7,8) along Atlantic Coast of e. N. America from Nfld. south to Va. (mainly Apr.-Oct. in Atlantic Canada, July-Apr. in U.S.) (note 9), exceptionally (Feb.-Mar.) in s. Tex. and Belize.
Black-tailed Gull is a distinctive species, perhaps most likely to be confused with California Gull.
Third Cycle. Third-cycle Black-tailed Gull looks much like adult, which see for differences from other species; some third-cycle Lesser Black-backed Gulls have black in the tail, but this does not form a neat, broad subterminal band.
END OF PART 1
|Black-tailed Gull (crassirostris) sub-adult, February 24 2015, Chidiwa Unzen city, Nagasaki, Japan. Picture: Nobuo Fukushima.|
|Black-tailed Gull (crassirostris) sub-adult, January 26 2007, Chidiwa Unzen city, Nagasaki, Japan. Picture: Nobuo Fukushima.|
|Black-tailed Gull (crassirostris) 3rd cycle (4CY), February 14 2016, Chidiwa Unzen city, Nagasaki, Japan. Picture: Nobuo Fukushima.|
|Black-tailed Gull (crassirostris) sub-adult, February 04 2011, Off coast Nagasaki prefecture, Japan. Picture: John Wright.|