The were a pair of Gang-gangs at a hollow in a tree closer to Garran. There was a very obvious, south-facing hollow in one tree. Both male and female spent time at the hollow, chewing around the edges. This pair swapped positions quietly, without any contact. They both moved away from the hollow while I was watching but stayed in the surrounding trees, occasionally calling. Neither bird went fully into the hollow so I am not sure how deep it was.