Yellow-legged Gull (atlantis, michahellis)

Yellow-legged Gull (atlantis, michahellis)

IMAGES:

Adult

DESCRIPTION:

YELLOW-LEGGED GULL(22"-27"; 54"-57") atlantis, michahellis

BILL SHAPE: slighlty shorter, thicker than argenteus; looks stubby w/ steep culmen at tip; 4x eye diam; gon angle small to med.
HEAD SHAPE: chunkier than argenteus; rather square w/ steep forehead, flattish crown; square nape
WING EXTENSION: slightly longer than bill length
POSTURE/HABITS: sturdy proud look w/ full chest and long legs; prefers shorelines; consorts w/ Lesser Black-backed
	FIRST CYCLE	SECOND CYCLE	THIRD CYCLE	ADULT
BILL COLOR:	black; some w/ slight flesh base to lower mandible	variable, often w/ yellowish base and dark tip	as adult w/ black mark	often bright to orange- yellow, some duller; gon. spot large and red, often into upper mand; 80% w/ black mark or subterm band in fall
LEG COLOR:	pink	fleshy or yellowish; rich yellow by spring	as adult	variable yellow; bright to orange-yellow in spring; very rarely pale flesh (not pink)
IRIS/ORB RING:	dark	dark on most; red orb ring by summer	often dark	dull gray-yellow to bright lemon; dark very rare; orb ring red to orange-red
HEAD:	many quite white-headed w/ thin line behind eye; others w/ streaky crown and nape w/ white background and white under and behind aurs	white w/ dark smudge in front and under eye, line behind; possibly thin streaks on crown and nape; splotchy collar	as adult; more likely to have thin streaks	white w/ variable fine streaks from eye to rear crown; may be on nape and auriculars; most white by Dec.
UNDERPARTS:	fairly white w/ streaky breast band and flanks; undt. covs white w/ sharp dark bars	white w/ splotchy breast sides	white	white
PRIMARIES (folded):	black	black	black w/ tiny A-spots or white crescents	A-spots evenly spaced; A9-10 same size as eye; A7-8 slightly larger
PRIMARIES (in flight):	dark outer Ps w/ pale window on inner Ps, due to pale inner webs of inner Ps, subtle from above, more obvious from below; 50% of michahellis show small pale oval on inner webs of inner Ps; window faint or lacking on atlantis	blackish outer Ps w/ pale window on inner Ps; more obvious from below	black w/ small mirror on P10 only; other- wise as adult	extensive black area; large (may be terminal) or med mirror on P10; half have mirror on P9; P5 always w/ black band; P4 and even P3 may have black marks; similar from below w/ pale area med pale gray
SECONDARIES (in flight):	dark w/ pale fringe above and below; underwing covs rather dark	blackish w/ pale fringe; fairly dark below; under- wing covs w/ dark rows	as adult	adult gray w/ bold white trailing edge, 1/2 to 1/3 bill length
TERTIALS:	solid dark, nearly black, w/ broad pale tip; some white notches possible	dark w/ irreg mottled pale tips	as adult	adult gray w/ white crescent, about 2/3 bill length
GREATER COVERTS:	outer feathers solid dark g-b w/ subterm spots; inner ones more spotted; atlantis may be more solid dark	irreg pattern of dark g-b and adult gray	adult gray	adult gray
LESSER & MED COVERTS:	rather dark w/ some pale fringes and some pale internal bars	many w/ adult gray on median covs; les covs dark g-b w/ some pale fringe	adult gray	adult gray
SCAPULARS:	cream, fading to white, w/ large subterm anchors and dark at base; appearing barred	adult gray on most	adult gray	adult gray w/ small white crescent usually visible
BACK:	like scaps, appearing irreg. barred	adult gray on most	adult gray	adult gray is med gray, darker than argenteus, paler than graellsii, same as Common; atlantis is slightly darker, closer to graellsii
RUMP:	quite white w/ light irreg bars	white	white	white
TAIL:	white w/ blackish tail band, white outermost webs and fringe; some barring at bases	like 1W but w/ whiter bases and some mottling on inner retrices; tail band appears sharper	white w/ irreg thin jagged black band, not extending to outer retrices	white