Oystercatchers are six rather similar-looking species of oceanic shorebirds that comprise the family Haematopodidae. Oystercatchers occur widely on sub-arctic, temperate, and tropical seacoasts, on all of the continents except Antarctica.
Oystercatchers are relatively large shorebirds, with a body length of 15-21 in (40-53 cm). They have pointed wings, a short tail, short but heavy legs, and three-toed feet. Their most distinctive feature is their long, blunt, knife-like (that is, vertically flattened), red or orange beak. This unique bill is used as a hammer and in a wedge-like fashion to twist open the shells of reluctant bivalves upon which oystercatchers feed. Oystercatchers also eat crustaceans, polychaete worms, and other intertidal and shoreline invertebrates.
Oystercatchers are strong, direct fliers. They typically occur on sandy or rocky beaches. Oystercatchers are wary birds, and when they detect a potential danger they repeatedly utter a loud, clear, piping sound as a call note.
Oystercatchers build their crude scrape-nests on remote, open beaches, or sometimes in fields and meadows near the coast. They lay two to four eggs, which are incubated by both parents, which also share the care of the young birds. Parent oystercatchers put on very convincing broken-wing displays to lure predators away from their nest or babies. Young oystercatchers are able to follow their parents soon after birth, and are able to fly and feed themselves after about five weeks.
All species of oystercatchers are in the genus Haematopus. Two species occur in North America. The American oystercatcher (H. palliatus) is a black-backed, white-bellied species that occurs on mudflats and sandy beaches of the southeastern states and western Mexico. The black oystercatcher (H. bachmani) is an all-black species that tends to occur on rocky beaches.
The most widespread species of oystercatcher in Eurasia (H. ostralegus) is sometimes known as the seapie or mussel-pecker, and is a black and white species. The sooty oystercatcher (H. fuliginosus) of Australia is an all-black species.