White-rumped Sandpiper

How to find it

Scan open, shallow spots such as flooded fields, shallow ponds, marsh edges, mudflats and tidal flats. Look through flocks of other small sandpipers rather than for a lone bird. Check wing length first, because at rest the wingtips reach past the tail. Wait for birds to take flight, since the white rump shows mostly then, and that is the moment to compare it with Baird's Sandpiper. Listen for the thin tzeet, which is usually given in flight.

How to recognise it

Look first at the wings. At rest the wing tips reach past the end of the tail, which gives a long, pointed look from behind.

Size helps among other small sandpipers. It is about the size of Baird's Sandpiper and larger than Least, Semipalmated and Western Sandpipers.

The field marks, in short:

- Wingtips passing the tail tip at rest.

- A white eyebrow stripe.

- Greyer overall than Baird's Sandpiper.

- In spring, black streaks on the chest and down the sides.

- In juveniles, clear V-shaped pale lines on the back and shoulder feathers.

The white rump that gives the bird its name shows only in flight. The long wings often hide it when the bird is perched.

What it sounds like

Recording: Dan MacNeal, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

A Costa Rica bird guide describes the genus Calidris as small, fast-moving birds normally seen running along the ocean shore. This species is one of the northern migrants that fit that pattern.

On its journey it flies long non-stop legs and depends on rich stopover wetlands to refuel. Scanning through flocks of other small sandpipers is the way to pick it out, and listening for the call can help you notice it before you see it.

Where it lives

A Costa Rica bird guide lists it as a northern migrant. Along its migration route it uses flooded fields, shallow ponds, freshwater marsh edges, tidal flats and gravel beaches.

In the north of Costa Rica, trips visit the Chomes Salt Ponds, a mix of dry forest, salt ponds, mudflats and seasonal wetlands. They also visit the rice fields and wetlands around Palo Verde. Open, shallow places like these are the habitat to check.

When to see it

An older Costa Rican paper reports it at Salina Bonilla, Gulf of Nicoya, in mid-October and mid-May.

Similar birds

Baird's Sandpiper looks very similar but has a dark rump and is less grey overall. The white eyebrow stripe of this species also helps separate the two.

Against Semipalmated Sandpiper, look at the wings: Semipalmated is smaller and its wingtips do not reach past the tail at rest.

Names and lore in Costa Rica

The Costa Rican list name is Correlimos Lomiblanco. Other Spanish names include correlimos culiblanco, correlimos de Bonaparte, playerito de rabadilla blanca, playero de lomo blanco and chorlito de rabadilla blanca. Patudo and Becacina are shared nicknames for sandpipers, also given to Least and Pectoral, so they are not names for this species alone.

Status and conservation

The official Costa Rican list (AOCR, updated June 2026) marks it as a migrant (M), a visitor passing through rather than a resident.

Photography tips

Check open, shallow spots such as flooded fields, shallow ponds, freshwater marsh edges, tidal flats and gravel beaches. Look among flocks of other small sandpipers. The white rump shows in flight, so that is the moment to compare it with Baird's Sandpiper.