Gulls (Laridae)

Ring-billed Gull (Larus delawarensis) - HBW 3, p. 604

French: Goéland à bec cerclé German: Ringschnabelmöwe Spanish: Gaviota de Delaware

Taxonomy: Larus Delawarensis Ord, 1815, Philadelphia.
Morphometric analysis links it most closely with L. californicus. W population significantly larger and possibly subspecifically distinct. Monotypic.

Distribution: N California, E Washington and interior British Columbia across prairie provinces and N mountain and plains states; Great Lakes to Maritime Provinces. Winters in S portion of breeding range S to Gulf Coast, Central America and Greater Antilles, increasingly ranging to Lesser Antilles.