The Ruddy Turnstone is one of the most conspicuous migratory coastal birds that pass through the Pacific coast of Costa Rica. Their plumage is fairly colorful, with white underparts, orange legs, wings that are patched in orange and black, black throat and gray head with black markings. This is true of breeding adult males, but also of females and juveniles, although with streaked face and throat instead of black. Juveniles are duller, but not easily confused with other sandpiper species, as they are generally bigger and their body shape is different.
The Lesser Yellowlegs is a coastal bird, very similar to the Greater Yellowlegs, albeit smaller as one would expect. Telling one apart from the other is difficult, as the size difference may not be apparent if both species are not close by. Both have long, bright yellow legs, with white underparts and mottled gray upperparts, which turn brownish during the non-breeding season. The bill is long and slender, mostly black, although non-breeding adults may show a very small basal portion that’s colored in yellow.
The Whimbrel is a mid-sized coastal bird with a relatively down curved, long bill. Its body is grayish brown with a mottled appearance, where some of the subspecies having a white back and rump. Its call is a high-pitched whistle. They appear very similar to the Curlews, however those species are much larger in comparison. They forage in the shallow waters along the coast, grabbing small invertebrates and crabs from the surface.
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.
Most Sandpiper species are pretty similar, specially as they come to Costa Rica in non-breeding plumage. Having a few different species mixed up in a single group can help for identification, as some of them will be showing the breeding plumage that distinguishes them, as well as other features like leg color. In this case, the Least Sandpiper has yellow legs, distinguishing it from the very similar Semipalmated Sandpiper. Also this bird is similar to the Pectoral Sandpiper, however the Pectoral is a lot bigger, has a yellowish bill, and the breast is streaked and delineated vs the white belly.
The Black-necked Stilt is a wader bird, meaning it walks in shallow waters, looking for small prey to snatch. It does not dive and is not usually seen swimming. The stilt has a streamlined body and extremely long pink legs, allowing it to wade in deeper waters than other, smaller waders found in Costa Rica like the Plovers and Sandpipers. It has a contrasting black and white body. When startled, they usually fly away in a wide circle and return to a similar place they were before.