Dark-billed Cuckoo

How to find it

Start in the far south, around Ciudad Neily. The area seems to attract Coccyzus cuckoos regularly, with several Mangrove Cuckoos seen there and Yellow-billed Cuckoos reported by others. That makes it a sensible place to check each cuckoo for a rare Dark-billed. Look at the rice fields south of the hospital, where the first bird was found. Scan open perches such as fence wires, and take photos, because identification here depends on them.

How to recognise it

This is a slim cuckoo about 25 to 28 cm long, roughly half of that being tail. Males and females look alike. These details describe the species across its range.

Look for these marks:

- Gray crown and nape.

- Grayish brown upperparts.

- Pale buff underparts.

- A wide black mask through the eye.

- A black bill.

- A black undertail with broad white tips on the outer feathers, seen as big white spots beneath a long dark tail.

- Narrow bare skin around the eye, which can be yellowish, olive or gray, with no noticeable eye ring.

In Peru the upperparts are described as warm gray, with the buff below varying to brown.

What it sounds like

Recording: Jose Luis Navarro, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

Unlike many cuckoos, this species is less secretive across its range and may perch in the open, for example on fence wires. That habit helps anyone scanning open country.

It is not a brood parasite. A pair builds its own stick nest and raises its own chicks. The diet is mainly insects. These habits are described from its South American range, not from Costa Rican observations.

Where it lives

Across South America the species uses many forest types, including dry, evergreen and humid forest, plus forest edges and trees in farmland. It is normally found from sea level to about 1,200 m, and has been recorded as high as 3,600 m in dry mountain valleys and Andean slopes.

In Costa Rica the only named spot is in the far south, near Ciudad Neily in Puntarenas, close to Panama. The bird there was logged at rice fields.

When to see it

The only Costa Rica record described was in January, near Ciudad Neily. The species is called an Austral migrant, meaning it moves north from southern South America, but Costa Rica has too few records to show a pattern.

Similar birds

The Yellow-billed Cuckoo looks extremely similar, so photos are needed to confirm a Dark-billed. A Ciudad Neily sighting in 2021 was never confirmed because it could have been a Pearly-breasted or Yellow-billed Cuckoo. Pale birds can also resemble a Black-billed Cuckoo, but the Dark-billed has buff underparts, barely visible orbital skin and a dark tail with large white spots.

Names and lore in Costa Rica

The official Spanish name in Costa Rica is Cuclillo Piquioscuro. Elsewhere the same bird is called cuclillo canela in Argentina and Bolivia, papa-lagarta in Brazil, cuclillo de pico oscuro in Peru and cuco piquioscuro in Colombia.

Status and conservation

The official Costa Rica list marks the Dark-billed Cuckoo as A, accidental, while across South America it is fairly common, stable and rated Least Concern by the IUCN.

Photography tips

Photos matter more than usual with this bird, because the Yellow-billed Cuckoo looks extremely similar and an earlier sighting went unconfirmed. Try to capture the buff underparts, the black bill and the undertail with large white spots.