The hollow branch is the lowest large branch pointing in a generally easterly direction.
The male was standing watch while the female was peering into the hollow. When she saw us she persisted for a very short while but then led the male off the tree. Around 2 hours later I checked the same site and no Gang-gangs were present. The hollow can best be seen from just inside the Reserve, looking north. The tree is on the roadside reserve near the Gininderra and Gungahlin Drive intersection. Happy to discuss further if required.