Sahul Brush Cuckoo

The Sahul brush cuckoo is about 22–26 cm (8.7–10.2 in) long. The plumage of adult males and females is similar. The head is pale grey, the breast is buff, the back is grey-brown, and the underside of the tail is brown with white tips and bars. The eye has a narrow, pale ring around it, and the feet are olive-pink. Juvenile plumage is heavily barred dark brown. The wings are sharply pointed and backswept in flight. Underwings are grey-brown with pale buff underwing coverts and a white or pale buff bar. The Sahul brush cuckoo has a similar appearance to the pallid cuckoo, and especially the fan-tailed and chestnut-breasted cuckoo.

The Sahul brush cuckoo is found in northern and eastern Australia, the Solomon Islands, New Guinea, Malaysia, and other islands to the north of Australia. It is resident in parts of its range, such as in Thailand, peninsular Malaysia, Cambodia and southern Vietnam, the Philippines, the Greater Sunda Islands, Lesser Sunda Islands, the Maluku Islands and Timor. It may migrate locally in New Guinea and northern Melanesia. In Australia, it is migratory in the southern part of its range. In Australia, it is known to inhabit a range of environments including rainforests, rainforest edges, mangrove forests, secondary forests, and plantations.

The Sahul brush cuckoo is a brood parasite. Its eggs are polymorphic, meaning females lay specific egg types for specific hosts. In Australia, females lay three types of egg depending on their major host in the relevant region of their distribution. Across its Australian range the Sahul brush cuckoo exploits at least 58 other avian species, though only a small number of species have been observed raising chicks through fledging. The species observed to raise chicks through fledging vary by subspecies of the Sahul brush cuckoo. For C. v. dumetorum they include the purple-crowned fairywren, brown-backed honeyeater, bar-breasted honeyeater and for C. v. variolosus they include the rose robin, Norfolk robin, leaden flycatcher, restless flycatcher, satin flycatcher, rufous fantail and grey fantail. In Indonesia, observed hosts of the local subspecies of Sahul brush cuckoo include the grey-headed canary-flycatcher, Javan blue flycatcher, snowy-browed flycatcher, Sunda forktail, long-tailed shrike, striated grassbird, sooty-headed bulbul, yellow-vented bulbul, Malaysian pied fantail, rufous-tailed fantail, pied bush chat, Buru white-eye and Sangkar white-eye.