61 



KEY TO GULLS (Cont.) 



61 Plumage marbled with pinkish-buff feather edgings; bill pink basally, 

 with clearly defined black tip; primaries more or less pointed, 



tail feathers rounded at tips. GLAUCOUS GULL, first year 



61' Plumage paler, nearly all white, sometimes with pale gray on back; 



primaries more rounded, tail feathers more squarish at tips. 62 



62 Pale gray feathers present on back. 63 



62' No pale gray on back, some individuals may approach pure white. 



GLAUCOUS GULL, second year 



63 Tail pure white; bill yellow with red spot at gonydeal angle. 



GLAUCOUS GULL, adult 



63' Tail often freckled with dusky or smudged terminally; bill usually 



with a dusky band near tip. GLAUCOUS GULL, third year 



