The black-billed cuckoo preys upon cicadas, crickets, grasshoppers, butterflies, fish and wild fruits and berries. It also consumes large numbers of spiny, noxious caterpillars. Often the caterpillar spines become lodged in the stomach wall, so from time to time the stomach lining is shed to get rid of them (2) (7).
Both adult black-billed cuckoos help build the nest, which is constructed from twigs and grasses and lined with leaves, pine needles, stalks, plant fibres, rootlets, mosses and spider webs. Like many other cuckoo species, the black-billed cuckoo occasionally lays its eggs in the nests of other birds. The young leave the nest at six or seven days old, and are able to fly at around two weeks of age (2) (9).