What's that woman doing down there?

We had a great walk through bush and trees alongside the lake at Narabeen. We could hear all sorts of bird noises, but most of all was the screeching of a large group of these cockatoos. They were flying here and there, swooping around, and then a group of three settled on a bush just ahead of us, and started nibbling at these green shoots.
This is a Sulphur crested Cockatoo, and is the largest Cockatoo in Australia. Apparently a lot of them are kept as pets...