I arrived at the site in sighting 4404794 and timeline to find some sort of territorial dispute in progress. There was much noise, and I found 4 birds in a tree across the track. Image 1 shows the new pair working on a hollow at lower left, while the original pair with the bald-headed male sit on a branch at upper right. In Image 2, the bald male attacks male 2 at the hollow while the two females stay out of the way. In Image 3, the bald male takes over the hollow while male 2 attacks female 1 and female 2 watches from below the hollow. Image 4 shows female 1 falling through the air towards female 2 after the attack. In the last image the two males fight at the hollow. The sequence is continued in the next sighting (4407815).