Ann, I fell asleep in the chair. Yes, that is them - Allocasuarina and this one is A. littoralis, usually called Black She-oak. It is the favoured food tree of the endangered Glossy Black-cockatoo, which nests on the island.
I have many she-oaks here both male and female. The sound of the wind whispering through the needles is wonderful. I think the word susurration was specially coined for them.
I often wonder how the word came about. I reckon susurrus is onomatopoeic and the romans coined it as they listened to the whispering of the trees while lying in sacred groves.
This tree is male I think.