Cuckoos in Carden

Ron Pittaway

First published in Toronto Ornithological Club Newsletter, March 2019, No 285.


Black-billed Cuckoo

Yellow-billed Cuckoo      Photos by Jean Iron


The Carden Alvar is a good spot to hear and, if you’re lucky, see the uncommon and secretive Black-billed Cuckoo. The similar Yellow-billed Cuckoo is rarer in Carden. The name “cuckoo” originates from the song of the Common Cuckoo of Eurasia which sounds like a cuckoo clock.

IDENTIFICATION: The adult Black-billed Cuckoo has a mainly blackish bill, red eye-ring, and small white undertail spots. The adult Yellow-billed has a mostly yellow bill, yellow eye-ring, and large white undertail spots. In flight the Yellow-billed shows conspicuous rufous on the spread primaries while the Black-billed has no or minimal amount of rufous.

SONG: Cuckoos are more often heard than seen because they sing hidden inside a tree’s foliage. The Black-billed Cuckoo sings a fast rhythmic dovelike cu-cu-cu repeated in a series. The Yellow-billed gives a hollow wooden ka ka ka ka ka kow kow kowp-kowp-kowp-kowp that slows at the end. Some calls, however, are hard to identify to species. Both species sometimes vocalize at night.

HABITAT: Cuckoos inhabit open woodlands with clumps of trees, dense thickets, and tangles.

HABITS: Most cuckoos are seen when they fly low and swiftly across open areas before darting back into cover. Keep your binoculars ready to lock onto a flying cuckoo to check the colour (plain or rufous) on the spread primaries. Perched cuckoos often sit still for long periods. If you spot one, you should get good views by being quiet and moving slowly.

WHEN: Cuckoos are late migrants and usually not seen in Carden until late May. Their numbers increase every few years during outbreaks of Tent Caterpillars.

ACKNOWLEDGMENTS: I thank Michel Gosselin for proofing and Jean Iron for photos.