These are quite large doves (39-45 cm) with a call that sounds vaguely like a Cuckoo, hence the name. They eat mostly fruit and have a particular liking for the introduced tobacco-tree. The bird in the second photo had been chased into our window by a group Noisy Miners and a Grey Butcherbird. It was fine and flew off a few minutes later, only to be chased again.
2: Mt Lewis, Qld, 16/10/2011.
2: Hornsby, NSW, 22/10/2009.