Atlantic Yellow-legged Gull (atlantis)
(last update: October 12, 2011)
Atlantic YLG 4cy January
Below you will find a description of YELLOW-LEGGED GULL (Larus michahellis), as published in one of the best Gull publication: "Gulls of the Americas" by Steve Howell & Jon Dunn.
"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 21-26.3 IN. (53-67 CM)
This large yellow-legged gull is a casual visitor to e. N. America from Europe. Adult overall intermediate in appearance between Herring Gull and Lesser Black-backed Gull. Bill fairly stout and parallel edged (more so on nominate michahellis); gonydeal expansion varies from slight to moderate. Adult upperparts medium gray to pale slaty gray (Kodak 6-8.5; see Taxonomy) with fairly extensive black wing-tips (white mirrors on outer 1-2 primaries) and, in basic plumage, relatively limited dusky streaking mainly on head. ]uveni1e brown overall with contrasting white tail base and black distal tail band. Subsequent ages variable in appearance. First cycle has black bill, flesh legs become yellow by adult cycle; adult eyes pale lemon; orbital ring reddish. Breeding and molt cycles average 1-2 months earlier than American and European Herring Gulls.
Two widely recognized taxa in w. Europe: the smaller (21-24 in.; 53-61 cm), shorter-legged, and darker-backed (Kodak 7-8.5) atlantis of the Azores (Atlantic Yellow-legged Gull), which was once treated as a race of Lesser Black-backed Gull; and the larger (21.7-26.3 in.; 55-67 cm), longer-legged, and paler-backed (Kodak 6-7) nominate michahellis of the Mediterranean region (Mediterranean Yellow-legged Gull), which was once treated as a race of Herring Gull. Birds breeding along Atlantic coasts from nw. Spain to Morocco (including so-called Cantabrican Yellow-legged Gull in nw. Spain), and on the Canary Is. and Madeira may represent one or more unnamed taxa of Yellow-legged Gull. Pending more study of the complex, in the descriptions below we provisionally include Cantabrican birds with michahellis, and birds from the Canary Is. and Madeira with atlantis.
STATUS AND DISTRIBUTION
S. Europe and islands off nw. Africa, including Azores. Casual nonbreeding visitor (mainly Oct./Dec.-Mar./Apr.; also June and Aug. records from Que.) to e. N. America from Atlantic Canada (mainly Nfld.) south to Mid-Atlantic coast, exceptionally Tex. (]an.-Apr. 2004). An Aug. specimen from Que. has been referred to Azorean L. m. atlantis; provenance of other birds uncertain.
CONTINUE PART 2: FIELD IDENTIFICATION
|Atlantic YLG (atlantis) sub-adult, January 31 2008, Azores Islands. Picture: Dominic Mitchell. Black centres on greater primary coverts and reduced black bill-band indications for near adults.|