Nesting hollow maintenance?

[Nick Payne <>]

This is the same nesting hollow in Capt Cook Crescent where I observed 
the parent Galahs trying to entice their young out of the hollow on 29 
October. This time one of the adults was sitting on a branch, and the 
other was perched below the entrance to the hollow, alternating between 
preening down near its tail, and rubbing its beak back and forth across 
the bare part of the tree trunk below the entrance. I watched it for 
several minutes, and it stayed in exactly the same position below the 
entrance, alternating repeatedly between these two actions. I couldn't 
see the purpose behind this. Can anyone explain it?
Nick Payne

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