Yeah your right dave channel bills winter in Papua
Aside some shrikes in the bird book Tony it does mention grey currawongs get darker west of melbourne , maybe its a visitor from the coast .
My wife befriended a family of crows a couple of years back , very smart birds, give them dry bread , no worries they go dip it in the bird bath , to much to eat they go hide it under a leaf or bit of grass for later.
Nearly always there would be a couple of currawongs sitting in the tree watching and soon as the crow left they go pinch the food ,,, its a crack up when the crow returns runs over to the leaf , lifts it and theres nothing there

and starts lifting other leaves in vain hope