Ruddy turnstone but it feeds mainly on invertebrates. Insects are particularly important in the breeding season. At other times it also takes crustaceans, molluscs and worms. It often flips over stones and other objects to get at prey items hiding underneath; this behaviour is the origin of the name "turnstone". It usually forages in flocks. They have also been observed preying on the eggs of other bird species such as gulls, terns, ducks, and even other turnstones, though this behaviour is uncommon. In the majority of observed cases, turnstones typically go after undefended or unattended nests, puncturing the shells with their beaks
Turnstone applies. The black turnstone ("Arenaria melanocephala") has a similar structure to its widespread relative, but has black upperparts and chest, and white below. It has a much more restricted range than the ruddy turnstone, breeding in western Alaska, and wintering mainly on the Pacific coast of the United States. There exists a fossil bone, a distal piece of tarsometatarsus found in the Edson Beds of Sherman County, Kansas. Dating from the mid-Blancan some 4-3 million years ago, it appears to be from a calidriid somewhat similar to a pectoral sandpiper, but has some traits reminiscent of turnstones. Depending on which