In the next tree we saw this bird:
I think it's a gang gang cockatoo. I can't recall seeing one so close to the city ever before, but maybe they are less rare than I think.
When I checked on the internet, I saw this clip, which looks to me like the same bird:
I checked once again at Birds In Backyards and read:
They are widespread in eastern New South Wales from the central slopes and tablelands to the south coast, down through Victoria's north-eastern regions to Seymour, with some records in east Melbourne, Mornington Peninsula and south-western Gippsland.Rosanna is in the north-east of Melbourne.
Aren't we lucky to have these glorious creatures flying free around us?