The Semipalmated Plover is a small migratory bird that can be spotted in early September at the Pacific Coast of Costa Rica. The upperparts are gray-brown, with a white collar around the neck, white forehead, black mask on the face and small bill with orange basal half and black tip. The underparts are mostly white, except for a black breast band. The delicate legs are orange. It looks very similar to the bigger Killdeer. They wade in beaches and shallow mud flats where they can grab crabs and small insects.
The Killdeer is a small bird similar to the Plover family. They are migrants that spend winter in Central and Southamerica, from late August to May. It is the only plover that shows two black bands on the chest, along with the orange edge of the eye. During the flight, they show mostly white on the underparts, brown on the upperside with tawny rump. They are noisy when flying, particularly if spooked, delivering a very high-pitched sound for which it receives its English common name.