in August and September. Behaviour The channel-billed cuckoo is often shy, remaining hidden in tree canopies feeding on fruit and most active in early morning and evening. Its loud raucous call makes it more often heard than seen. Other birds such as crows harass and chase it when they encounter it.Miner birds and crows and some other species also swoop them Breeding Channel-billed cuckoos are brood parasites; instead of raising their own young, they lay eggs in the nests of other birds. They are thought to form pair bonds for the duration of a breeding season. 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. Pairs also work together in order to aid the laying of eggs in host nests; the male will fly over the nest in order to provoke the nest occupants into a mobbing response, whereupon the female will slip into the nest and lay an egg. Alternatively the pair may work together by attacking an incubating bird, driving it off the nest and allowing the female to lay. The host species varies depending on the location; the most commonly targeted hosts are ravens, currawongs, butcherbirds and Australian magpies. Several eggs can be laid in a single nest, sometimes by different females. Often resembling those of currawongs and magpies (but not ravens), the eggs vary in colour and pattern, measuring 48 x 32 mm. They can be a reddish- or yellowish-brown to dull white, with darker brown splotches. The incubation period for this species is unknown. Upon hatching the chicks are altricial, being blind and naked. Unlike many other cuckoos, the chicks of the channel-billed cuckoo do not eject the other host eggs upon hatching or kill the host's chicks, but these seldom survive as the cuckoo chick is able to monopolise the supply of food. The chicks are fully feathered within four weeks, and leave the nest to clamber about on the branches, although chicks are fed for a number of weeks by the host parents after fledging. Diet Unusually for cuckoos, which generally take insect prey, but like the closely related koels, fruit forms a major part of the diet of channel-billed cuckoos. Fruits taken include those of several species of Ficus, including Moreton Bay fig (F. macrophylla), Port Jackson fig (F. rubiginosa), cluster fig (F. racemosa), strangler fig (F.