I merely needed to mention the dry garden to bring a weather system from the south with wind, rain and cold temperatures. We had 15mm overnight last night and more today.
As I walked across the yard on my return home this afternoon, the rosellas were back at the nest hole in the gum tree. I've been back out with the camera, but they're not there now.
I do think that it's the rain that changes their attitude to nesting. I'll be checking again tomorrow.