Buff-breasted Sandpiper

How to find it

Plan around fall passage, because flocks stay only briefly and a visit must coincide with their stop. Check open grass in Guanacaste and the Tempisque River basin. In the Central Valley, birders scan the airport runway grass. In a mixed group, check each bird, since it shares short-grass fields with other grass-loving migrants. Scan distant birds for orange-buff underparts first, then confirm the yellow legs.

How to recognise it

Start with colour. It is brown above, with a buff face and buff underparts in all plumages. At Chomes, distant birds were first noticed by their orange-buff underparts, and only then by their yellow legs.

The field marks in plain terms:

Bill: short, shorter than the head, and grey.

Legs: yellow.

Eyes: black.

Head: small and round, which gives a gentle, dovelike look.

Posture: it stands tall on its yellow legs.

Juveniles have fine black spots on the sides of the breast.

Behaviour and diet

Males perform a display that raises the wings to show the white undersides. They sometimes do this on migration, even when no other Buff-breasted Sandpipers are near, so a lone bird might still put on a show.

The species is known for being extremely tame, which is one reason hunters once took so many of them.

In Costa Rica, flocks stay only briefly. They can be at a site one day and gone the next, so a visit must coincide with their stop.

Where it lives

In Costa Rica it is a bird of open, short grass. Birders have found it in Guanacaste and on the grass at Juan Santamaria Airport in the Central Valley. A Costa Rican report advises searching the Tempisque River basin, in the Pacific northwest lowlands.

In spring it is regular only along the Caribbean coast, in April.

Range wide, it breeds on arctic tundra and winters mainly in South America, especially Argentina and Uruguay.

When to see it

Fall migration brings it through, with sightings in September and October. A Costa Rican report calls it rare and sporadic in fall, from late August to late October.

Similar birds

Ruff, especially a juvenile, can look similar. The Buff-breasted is smaller and more delicate, with a shorter, finer bill, and its legs are always yellow, while a Ruff's vary from orange to greenish. Juvenile Buff-breasteds have fine black spots on the sides of the breast, which a juvenile Ruff lacks. Upland Sandpiper is taller and slimmer, with a longer neck, a whitish belly barred on the sides, and a yellow bill with a dark tip.

Names and lore in Costa Rica

The Spanish name on the Costa Rican bird list is Praderito Pechianteado, and the list also gives the nickname Zarceta in brackets. Birders in Costa Rica often call it a "Buffie".

Status and conservation

The AOCR list marks it as M, a migrant, and in Costa Rica it is a scarce passage migrant, with more sightings in recent years probably reflecting more skilled birders looking.

Photography tips

Scanning the airport runway grass is how birders look for it in the Central Valley. One Costa Rican birder's search of the runways found none on a September day, so luck and timing matter. It travels with Upland Sandpiper, American Golden-Plover and Baird's Sandpiper, which often share the same short-grass fields.