The Black-belied Plover (Pluvialis squatarola) or Grey Plover is a medium-sized plover breeding in Arctic regions. It is a long-distance migrant, with a nearly worldwide coastal distribution when not breeding. In Costa Rica, those birds visit Gulf of Nicoya, Gulf Dulce and the Caribbean Coast. Its size is 30 cm (12 inches) and it has 190 g.
These birds prefer to live in mudflats, Salinas, estuaries, sandy beaches, grassy fields and sometimes in mangroves. Adults are dusky-brown and they have a different plumage in winter. Youngest plovers are similar to the oldest but with breast more heavily marked. The diet includes crabs, insects, crustaceans and marine worms.