If you have been awakened in the middle of the night lately by an unusual bird cry that sounds a bit like trying to start a car with a flat battery, it could be that of the migratory Channel-billed Cuckoo.
Nature photographer and Alfords Point resident Greg Tannos describes the sound as "a loud unusual prehistoric cry of 'gkwark-awk-awk-awk'."
The cry is better listened to in the video below, which Mr Tannos posted on his Find My Australia Facebook page.
"The migratory Channel-billed Cuckoo flits in and out of Sydney each year around spring and summer," he said.
"Being a cuckoo, it lays its eggs in the nest of another bird, and being a large cuckoo, it must lay its eggs in the nest of another large bird.
"The species usually chosen as foster parents are Pied Currawongs, Australian Magpies, crows and ravens, although occasionally eggs are laid in the mud-nests of White-winged Choughs or Magpie-larks, and very occasionally in the nests of birds of prey
"Although they are not nocturnal in the strict sense, Channel-billed Cuckoos are notorious for calling all night long during the breeding season.
"This species is sometimes known as the Storm-bird or Stormbird."
The Australian Museum says the Channel-billed Cuckoo lays its eggs in the nests of the Australian Magpie, Gymnorhina tibicen, the Pied Currawong, Strepera graculina and members of the crow family (Corvidae).
"Unlike many other cuckoos, the young birds do not evict the host's young or eggs from the nest, but simply grow faster and demand all the food, thus starving the others," the museum says.
"Often the adult female will damage the existing eggs in the nest when she lays her own and she may even lay more than one egg in a single nest."