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
WHEN: Cuckoos are late
migrants and usually not seen in Carden until late May. Their
numbers increase every few years during outbreaks of Tent
ACKNOWLEDGMENTS: I thank
Michel Gosselin for proofing and Jean Iron for photos.