American Herring Gull (smithsonianus)

(last update: October 30, 2015)

American Herring Gull 4cy February

GULLS OF THE AMERICAS

- Steve N.G. Howell / Jon Dunn -

Below is a copy of chapter 25 about American Herring 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.

American Herring Gull (smithsonianus)

PART 1: IDENTIFICATION SUMMARY

PART 2: FIELD IDENTIFICATION (BELOW)

SIMILAR SPECIES

Because of hybridization, especially in w. N. America, determining where a pure Herring Gull starts and a hybrid stops can be difficult, if not impossible, in the field; see hybrid American Herring Gull accounts (pp. 482-485 in Gulls of the Americas).

Adult Cycle.
Distinctive in e. N. America, except for vagrants (see Rarer Species, below), but in the West compare with Thayer’s Gull and in w. Alaska with Vega Gull. Also see hybrid American Herring Gull accounts (pp. 482-485 in Gulls of the Americas). Note pale gray upperparts, clean-cut black wingtips, pale eyes, and structure. East Coast types (see Description) have more white in wingtips, whereas West Coast types (see Description) usually have more black in wingtip and a white mirror only on P10.

American Herring Gull (smithsonianus) adult, December 12 2013, Stevenson compost, Tompkins Co, NY (Kevin McGowan). Pale tongue on underside of P10 with angular end, in combination with full sub-terminal band. P9 medium mirror on innerweb. Black band on P5.	American Herring Gull (smithsonianus) adult, January 08 2013, Niagara River (Amar Ayyash). Thayeri pattern on P9-P10 and very deep pale tongues on outer primaries. Two spots on P5.
American Herring Gull (smithsonianus) adult, October 28 2007, Monterey Bay, CA (Jeff Poklen). West coast bird in active moult: P10 old, active moult in rectrices. Lacking obvious immature markings, but little black in the greater primary coverts. Bold winter streaking. Complete W-pattern on P5 and black on P4. Note very short P10-tongue, on far wing from below.	American Herring Gull (smithsonianus) adult, November 14 2004, Monterey Bay, CA (Jeff Poklen). This bird is most probably in adult plumage, as it lacks any immature markings in the greater primary coverts, tail, secondaries or tertials. Bold winter streaking and paler base of bill. Incomplete W-pattern on P5 and a tiny spot on P4.

THAYER’S GULL (winters w. N. America) averages smaller and, especially, slimmer billed; upperparts average slightly darker (Kodak 4.5-6; differences rarely apparent in sunny conditions). Wingtip  patterns can overlap with smithsonianus, but dark areas on Thayer’s wingtips are slaty black (Kodak 14.5-17), not jet black as on Herring (Kodak 18-19), and are largely restricted to the tips and outer webs - so underwingtip of Thayer’s looks mostly silvery gray, not blackish as on typical Herring. Thayer’s eyes are usually dirty yellowish to brown, rarely staring pale lemon, its orbital ring purplish pink, and its legs often richer pink than Herring. On winter adults the dusky head and neck markings of Thayer’s are often more mottled, less streaked, and the bill rarely has distinct dark distal marks often shown by Herring. In w. N. America, where most Thayer’s winter, adult Herring rarely has a white mirror on P9, and its upperwingtip is more solidly black than almost all Thayer’s.

Thayer's Gull (thayeri) adult, January 17 2004, Capitola, CA (Jeff Poklen). Iris scoring is 0.0, iris uniformly dark brown; which is found in 2% of Thayer's Gull (see HERE). Note that at very close range, there will always be detailed speckling, shifting the category from uniformly to peppered.	American Herring Gull (smithsonianus) adult, May 09 2009, Newfoundland (Scott Grant). Orange orbital ring and staring yellow iris.
Thayer's Gull (thayeri) adult, February 22 2008, Vancouver Island, BC (Guy Monty). Dark iris.	Thayer's Gull (thayeri) sub-adult, February 11 2012, Pelagic off Lewes, DE (Adrian Hinkle). Note thayeri pattern on P9-P10, no black on P5.

CALIFORNIA GULL (W. N. America) usually told readily by dark eyes and gray-green (non-breeding) to bright yellow (breeding) legs, but beware some spring Herring Gulls with yellowish legs. California averages smaller with relatively longer and narrower wings, slimmer bill, and darker upperparts (Kodak 5-6 on larger albertaensis subspecies of California Gull could overlap with Herring). Wingtip of California has more-extensive and blunter-based black patch and averages more white in outer primaries than typical Herring Gulls wintering in the West; underwing shows dusky gray secondary bases, and bill has more-distinct black subterminal band.

California Gull (californicus) adult, May 22 2010 (Matt Sim). Much black in wingtip, in combination with large mirrors. Note red orbital ring and dark iris.	California Gull (californicus) adult, April 01 2010, Port Townsend, WA (Bob Whitney). Much black in wingtip, in combination with large mirrors. Red orbital ring and dark iris.
California Gull (californicus) adult, May 13 2012, Alberta (Raymond Lee). Reddish orange orbital ring and dark iris.	California Gull (californicus) adult, June 07 2009, Eleven Mile Colorado State Park (Ben Simo). Greenish-yellow legs and dark irides on all.

VEGA GULL (w. Alaska) similar in size and shape but upperparts noticeably darker (Kodak 7-8), eyes often darker, orbital ring reddish, black wingtip area averages more extensive, and underwing shows duskier secondary bases.

Vega Gull (vegae) adult, January 21 2011, Japan (Stuart Price). Dark iris, heavily streaked head continuing on upper breast, dark grey upperparts (Kodak 7-8), much black in wingtip (full subterminal band on P10), broad seconadry tips and pink legs.	Vega Gull (vegae) adult, December 2009 - January 2010, Choshi, Japan (Chris Gibbins). Dark iris, dark grey upperparts (Kodak 7-8).
Vega Gull (vegae) adult, December 2009 - January 2010, Choshi, Japan (Chris Gibbins). Dark iris, dark grey upperparts (Kodak 7-8), late moult (P8 fully grown, P9-P10 growing), and pink legs. Note purplish orbital ring.	Vega Gull (vegae) adult, December 2009 - January 2010, Choshi, Japan (Chris Gibbins). Dark iris, heavily streaked head continuing on upper breast, dark grey upperparts.

HYBRID GLAUCOUS-WINGED GULL X WESTERN GULL (w. N. America) can suggest Herring Gull when paler gray upperparts (around Kodak 6) combine with blackish wingtips. Aside from slightly darker upperparts note bulkier structure, especially broader wings (with short wing projection, usually distinct skirt) and more bulbous-tipped bill of hybrids. Also, blackish to slaty wingtips less clean cut, eyes often dusky (but can be pale, although usually more greenish white than pale yellow), and orbital ring often mixed pink and yellow.

Olympic Gull glaucescens x occidentalis adult, February 16 2009, Portland, Oregon (Lyn Topinka). Purple orbital ring and extensive speckling in iris ( >75%). Medium grey primary pigmentation, obviously darker than upperparts indication for occidentalis influences.	Olympic Gull occidentalis x glaucescens adult, December 03 2008, Vancouver Island, BC (Guy Monty). Pigmentation on primaries intermediate, and grey tone upperparts intermediate.

CONTINUE PART 3: FIELD IDENTIFICATION - FIRST CYCLE

East coast birds

South coast birds

sub-adults with vestiges of black (probably 5cy / 4th cycle)

Great Lakes