My very first thought was that this was a Grey Butcherbird, but the colour pattern was definitely not right for that. My second thought was that it was a Grey Shrike-thrush - although it looked rather large in comparison to the ducks - and I put this as a response to Paul's post.
Then two other contributors suggested Grey Currawong was more likely. For some reason I hadn't thought of that species but on looking again at the image it seemed a good suggestion which I endorsed. A further member of the group then put in another vote for Grey Shrike-thrush based on colouring and general shape.
This led me to ask Paul for an original of the photo which he provided by email. After looking at this I sent him images of Grey Currawong ...
... and Grey Shrike-thrush.
I asked Paul which he thought closer to the bird he'd seen noting:
- The colouration looks to me more like the Shrike-thrush (which I why I went there initially) but shadows etc can be very tricky. The shape of the bill looks more like Grey Currawong than GST.
- The matter of size is a tad difficult as they are different distances away (and how to measure the length of a bird is tricky) but consider this:
- Pacific Black Duck is roughly 50cm long
- Grey Currawong roughly 45cm long
- Grey Shrike-thrush roughly 25cm long.
I couldn't do the geometry to prove it but allowing for the ducks to be about 1m further from the camera I'd rate the bird in question to be close to the same size, or at least significantly more than half the size of the ducks. So that is a vote for the Currawong.
GST are quite common around the area (nest in people's sheds etc) but Grey Currawongs have been around our place regularly in the past few weeks.
Paul responded " ... it really is about as big as the full grown ducks and is strong enough to scare off the magpies and rosellas when it is after seed on the lawn. This matches with the size information you have given me."
So my conclusion is that it is definitely a Grey Currawong.