The birds on the bird bath are juvenile Pied Currawongs - Strepera graculina - a bird that is found along all of the east coast of Australia, but does not occur in Tasmania. Although these birds look "crowish" they are more closely related to the Australian Magpie and Butcherbirds that true crows.
They have a remarkable voice - you can hear a little of there voice by clicking the player near the bottom of the right hand side of this link.
Currawong is probably a corruption of an onomatopoeic Aboriginal name (thats a hell of a sentence!) - but its scientific name means "Jackdaw-like noisy bird" - which is surly correct on the noisy part, but a little way of the mark on the Jackdaw bit!
In flight I always think these birds look long and thin, and they have long wings that seem to have a slight pause, giving the bird a gliding sort of flight. For a long time this was a bird I associated with autumn, as they would be calling from the trees around the school I used to work at as I arrived in autumn mornings - not hearing them as often as I once did is one of a very short list of things I miss about that job!
The part of the beak where it hinges is called the "gape flange" and in many young birds it is brightly coloured - you can see this is the bird batch images. This may act as both a marker of the health of the bird and as feeding stimulus for the adults.
This is the adult bird in pretty much all its glory. You can see the small hook on the beak which is a bit of a give away about its rather predatory diet. These birds often eat the chicks and eggs of other birds - and can do a bit of damage to songbird nests. But a birds got to eat!