It's a bit blurry, I'm afraid, but the only place I could get a photo from was quite a distance away. The birds are - as I discovered today when they flew over again and I got a glimpse of red - forest red-tailed black cockatoos. These particular cockatoos are a sub species of the red-tailed black cockatoo which are unique to southern Western Australia where they are listed as vulnerable.
They are feasting on 'something' on my neighbour's Silver Princess (Eucalyptus caesia) tree. The Silver Princess is a truly lovely small tree with silvery, weeping branches and large, spectacular red-pink blossoms which are followed by equally large - 30 mm in diameter - gum nuts. I suspect the 'something' is new buds or flowers because they flower from May to September and I noticed a couple of flashes of red among its leaves in this afternoon's photo below. If you look carefully you can see one flower in the middle of the left hand side upright branch and others up near the top on the far right and the reason you can see them at all is because these blossoms are big as well as beautiful.
I also suspect that there won't be many more flowers this year if the cockatoos keep on feasting but my neighbour, like me, is enjoying the birds at the moment.