Captain Arthur Phillip wrote of this (at the time) mysterious bird—calling it the 'psittaceous hornbill'—in his 1789 work The voyage of Governor Phillip to Botany Bay, consulting with ornithologist John Latham and deliberating that it had features of a parrot, hornbill or toucan, though conceding there were no toucans in the region.

[11] The only member of the genus Scythrops, the species is most closely related to the long-tailed cuckoo (Urodynamis taitensis), which breeds in New Zealand and winters in the Pacific islands, according to Sorenson and Payne (2005).

[12] "Channel-billed cuckoo" has been designated as the official common name for the species by the International Ornithologists' Union (IOC).

The tail is dark grey on top and barred underneath with a black band and white tip at the end.

[16] The channel-billed cuckoo is a strong flier, with a distinctive, almost hawk-like cross-shaped (cruciform) flight silhouette.

[13] There is some sexual dimorphism in both plumage and dimensions, the female having a smaller bill and paler, more barred undersides.

In recent years, the breeding range of these cuckoos appears to have extended further down the south coast of NSW.

[19] The channel-billed cuckoo is often shy, remaining hidden in tree canopies feeding on fruit and most active in early morning and evening.

Channel-billed cuckoos are brood parasites; instead of raising their own young, they lay eggs in the nests of other birds.

[20] Their mating behaviour has been described as involving calling and gift-giving, with the male presenting items of food such as insects to the female.

Alternatively the pair may work together by attacking an incubating bird, driving it off the nest and allowing the female to lay.

Often resembling those of currawongs and magpies (but not ravens), the eggs vary in colour and pattern, measuring 48 x 32 mm.

In northern Australia their migration coincides with the beginning of the rainy season, leading to the species being given a range of colloquial names such as storm-bird, flood-bird or rain-bird.