These large and stocky shorebirds are distinctive, with heavy red bills and loud displays. Two species in North America live in different habitats. The Black Oystercatcher of the Pacific Coast lives on rocky shores, and the American Oystercatcher lives on sandy beaches and mud flats on the Atlantic and Gulf Coasts. Oystercatchers use their bills to catch bivalves, surprising them while they are open with a quick jab to their muscles, so the bivalves can't close their shells. Oystercatchers will also hammer on a shell until it breaks open. Some individuals specialize in one or the other technique. Oystercatchers are ground nesters, and both sexes tend the young. Unlike other shorebirds, oystercatcher parents actively feed their young for several weeks after they hatch.