Many years ago rain forests in eastern Australia were known colloquially as brushes or big scrubs and that's where the Brush Cuckoo gets its name. The legendary Australian bird book, Cayley's "What Bird is That?" still has a section named Birds of the brushes and scrubs. Brush Cuckoos are generally associated with more humid environments in eastern and northern Australia such as edges of rain forest and mangroves, riverside vegetation and monsoon forest but are generally absent from drier environments further inland.

A few people have trouble distinguishing between Brush and Fan-tailed Cuckoos. The Brush Cuckoo always looks a very plain looking bird - the tail is shorter and has fewer white markings than a Fan-tailed but the clearest difference is in the colour of the eye-ring, bright yellow in a Fan-tailed and rather nondescript grey or pale yellow in a Brush. Their calls are diagnostic (listen on sound page).

Brush Cuckoos in the east are migrants, arriving in late September and departing at various times depending on the locality. Northern Australian birds are a different subspecies and generally regarded as being resident. They mainly parasitise birds that build open nests such as honeyeaters, robins, flycatchers and fantails and less frequently fairy-wrens and gerygones,