Dunlin

How to find it

Start at the Gulf of Nicoya, the area a tour checklist names for Dunlin sightings. Plan for the window from late December to early May, when birds have been reported there. Scan tidal flats, estuary edges and coastal lagoons, where Dunlins feed by probing mud. Check each flock of small sandpipers for a gray bird with a slightly downturned bill. Look for the short tail with white sides to the rump. Because it is very rare here, expect to scan carefully and listen for its call.

How to recognise it

Know both plumages, because the Dunlin changes with the season. In breeding plumage the adult has a distinctive black belly patch and rusty flecks on dark gray upperparts. In non-breeding plumage it is plain gray above and white below, so the belly patch will not help you.

Juveniles show a white V pattern on the shoulders and back.

The bill is moderately long and bends slightly downward, a useful mark on a small shorebird. The tail is short, with white sides to the rump.

These descriptions apply to the species across its whole range, so treat them as a guide to what to check on any small gray sandpiper.

What it sounds like

Recording: angelique_k, CC0 1.0, source, read 4 Nov 2026.

Behaviour and diet

Dunlins feed by probing mud. They eat insects and their larvae, marine worms, small crustaceans, snails and small fish.

In winter they are very sociable and often gather in large flocks on salt marshes and sandy beaches. Across the wider range those flocks can reach thousands or tens of thousands of birds, but Costa Rica birds are likely to be far fewer, since the species is very rare here.

Where it lives

On migration and in winter, Dunlins use tidal flats, estuaries and coastal lagoons. They also use the edges of inland waters. That describes the species in general.

In Costa Rica a tour checklist places it around the Gulf of Nicoya, on the Pacific side. The Pacific-coast group is the one known here as Correlimos Pechinegro. It winters in the western USA and western Mexico, so Costa Rica is likely near the southern edge of its range.

When to see it

A tour checklist says Dunlins at the Gulf of Nicoya are found from late December to early May.

Similar birds

Other small sandpipers can look much alike, and they are likely to share the flats with a Dunlin. The short tail with white sides to the rump helps separate it from them.

Names and lore in Costa Rica

A Costa Rican source lists the Spanish name Correlimos Pechinegro for the Dunlin. A wider Spanish-name list gives Correlimos Común as another name for it.

Status and conservation

The AOCR list marks the Dunlin as M, a migrant, and the IUCN lists it as Near Threatened worldwide.