A secretive island bird found nowhere on Earth except Cocos Island, a small, rugged island in the Pacific that belongs to Costa Rica. Because its entire world is basically one rainforest-covered island (about 550 km (342 miles) offshore), it feels like a “hidden local” even among cuckoos. It uses many habitats on the island—bay forests, streamside woods, rainforest, and even cloud forest—ranging from sea level up to about 450 m (1.476 ft).

Looks-wise, it’s built like a classic New World cuckoo: slender, long-tailed, and designed to slip through leaves rather than show off in open sky. Its colors are mostly soft and earthy: a slate-gray forehead and crown, grayish-brown back, and rufous (reddish) wings. The underside is warm-toned—buffy white throat and breast with a richer buff belly—so it can look gently sunlit even in shade. A fun field mark is the bill: the upper part is dark, but the lower part is yellow to yellow-orange with a darker tip, and there’s also a narrow ring of yellowish bare skin around the eye. Flip its tail in flight, and you may catch a bold pattern: the underside is dark with wide white tips.

Behavior is where it becomes extra interesting. The Cocos cuckoo is a year-round resident on the island, but it seems to shift its hangouts: it’s reported more around forest edges in the breeding season and more in the forest interior outside of it. It’s also a bird that’s often heard (if at all) more than seen, and recordings have been scarce; sources note that as of late 2022, there were very few recordings available in major archives. Its song has been described as a rough, throaty series of “eeh” notes, most often given during breeding season and mainly from dawn into late morning.

Distribution

Country

Population est.

Status

Year

Comments

Costa Rica

350-1,500

Official estimate

VU

2020

Cocos Island