Ring-billed Gull
Larus delawarensis
Resting on a sandy beach near the Colorado River delta, Golfo Santa Clara, Sonora, Mexico. 24 January 2015.
Probably the most familiar of gulls in the interior of North America. They have come to identify human activity with the possibility of obtaining scrap foods. Their presence in the Sonoran Desert is seasonal. Along the major rivers and lakes they appear in usually low numbers from October to March. At the shore of the Gulf of Caifornia they are the most abundant gull during the winter months. The dark bill ring is usually diagnostic.