Elusive, secretive birds often are the most satisfying to discover, and for me the black-billed cuckoo ranks near the top. Hearing a bird is usually the best way to find it, but attentive ears are needed to detect this cuckoo's song: a subtle, slow and hollow-sounding "cucucu – cucucucu." The song in no way resembles the bold double notes of a cuckoo clock that mimic the song of the common cuckoo, a species that nests across Europe and Asia.
Alerted by a black-billed's gentle "cucucu" notes, one just might get a look at a bird, about the size of a robin, but slender, with a long, graceful tail that sets it apart. A black, curved bill is backed by an eye with a bright red eye-ring that lends the bird a constantly startled look.
The old-time nickname for the species was “rain crow,” used generations back when people led their lives more outdoors than indoors. In those days, a farmer debating whether or not to hay knew to tune in to the "rain crow"-- they knew cuckoos sing on days that promise rain. Now, with weather channels to reference, we do not always pay attention to the weather clues that nature provides.
Cuckoos are also a farmer's friend in that their preferred diet is a unique one—hairy caterpillars. In years of gypsy moth and tent caterpillar outbreaks, cuckoos lay more eggs and produce more young. Back in the era of the "rain crow," when cuckoos were common, flocks would mob a tree infested with caterpillars and consume them all.
A species newly in decline, no longer common on their breeding or wintering grounds, their presence close by is all the more satisfying to discover.