Often during mating rituals the male or female will also thrash whatever bush, branch or tree they are on so that the other bird can see how strong they are. Strong birds make strong young, hence keeping the species alive. Cockatoos have different dialects in different flocks. Birds in flocks miles away have different languages, just as humans do in different countries. This helps the bird identify with its flock and its genaeology.
Cockatoos use tools.
Cockatoos can be seen clipping small sticks of wood and then scratching various bodyparts with these pieces, much like we would use a backscratcher. Cockatoos also take the pieces of wood and bang on wood and logs, trees and owners with them. Cockatoos are notorious for hiding beads of small items in their wings. They may walk around for hours before dropping the item out to play with it. Some enjoy taking this bead and playing the roll the bead game.