I could hear wood being ripped and found one of the pair busy tearing a wattle apart.
After a bit more excavation it found its favourite meal, a nice juicy grub, most probably a caterpillar of one of the Cossid moth species.
The wattle that was ripped apart is the Sydney Wattle Acacia longifolia that come up all across our property and are a bit of a weed, so not worried about the damage as I will be taking the tree out. We have lots of these and other trees that the caterpillars favour so there is no shortage of potential food sources for the Cockatoos.
|The exposed tunnel of the caterpillar|