Oklahoma Vagrants: Black-billed Cuckoo

More uncommon than local in woods with willows or alder and dense undergrowth, the Black-billed Cuckoo is believed to inhabit more of Oklahoma in the dense woods than originally thought.  While migrating in both spring and fall, the species can be found occasionally in the southern states.  Generally found east of the Rocky Mountains, they can also be observed in Canada.  Winter ranges are in the southwestern part of South America in humid tropical forests.

This is a slender cuckoo with a dark and decurved thin bill with small white spots on the gray-brown tail.  It is just as large as the Yellow-billed Cuckoo, and much shyer.

This elusive bird can be heard both day and night, skulking around concentrated forests and thickets.  They actually favor a wide range of habitat, most commonly located around edges of mixed or mature deciduous forests.  Abandoned farmland or parks can even be appealing to them as long as they can be well hidden and along the outskirts of these locations with a source of water.




            Black-billed Cuckoo
         High Island, Texas 2015

As many cuckoos are obligate brood parasites, this cuckoo incubates its own.  Chicks have sparse white down contrasting with dark skin.  They also have wart-like protuberances on the tongue and in the mouth, but that is normal for the species.

First seen at Rose Lake in 1976, the Black-billed Cuckoo made an appearance most recently at the Illinois River east of Tahlequah in May of 2018.  There have been several other sightings between the first and last notation.

During outbreaks of the gypsy moth, the Black-billed Cuckoo seems more abundant, as they tend to flock toward these areas, especially during breeding bird surveys.  They also show a predisposition for webworms, cicadas, and tent caterpillars.

During a tent caterpillar outbreak, they lay eggs earlier, could produce larger clutches, and may even behave more in an obligate parasite manner.  Not only will females lay eggs in the nests of other Black-billed Cuckoos, but they will also lay eggs as interspecific parasites, by choosing other species of songbirds.