White-faced Heron - Egretta novaehollandiae
We heard a constant knocking and found this huge bird on the windowsill but spooked it before we could grab the camera. Over the last few days it's got gamer, coming closer and closer, until this morning it came right up to the back door and knocked! Then it jumped up onto the table, had a walk around and propped!
We think it likes this place and has probably built a nest with its partner. It's said that when breeding the birds have long feathers (nuptial plumes) on the head, neck and back, which this one has.
More information: Birds in Backyards