Snowy Plover, Charadrius alexandrinus
			In breeding plumage, the front part of the crown, the ear patches, and the foreneck are extra dark, usually more blackish in males and more dark brown in females. In winter plumage (see bottom image) these areas match the rest of the dark plumage.
					The bands, which uniquely identify each bird, are put there by the good folks from Point Reyes Bird Observatory, who are in charge of studying and promoting the conservation of the colony of threatened Snowy Plovers on the beach near the mouth of the Salinas River on Monterey Bay, where all these pictures were taken. See their website to learn more about Snowies, and about PRBO programs to study and protect them, here.