Radjah Shelduck
These birds are monogamous and you usually see them in pairs or small groups. They are moderately common in the north east of Australia.
You can find them in waterways, wetlands, saltmarshes, mangrove and swamps. I see them most frequently at Centenary Lakes here in Cairns.
They can become moderately tame and have often been shot for sport/hunting. I find them at the Lakes to be quite easy to get close to but other areas quite skittish.
They are a very interesting bird to observe and if they take an interest in you they can soon become the one doing the observing. Their voice is a harsh rattling and commonly whistle in flight.