Head bobbing
Baby birds bob their heads when beseeching for food. Some adult birds will do so as well this to ask for food or to draw attention, which makes them excited. So glad “displaying” cockatoos will bob and sway their heads while their crests are up. Some cockatoos may not be wise to handle while they are displaying. They may even bite when overwhelmed. Cockatoos usually raise their crests when they are surprised, overwhelmed, and keen on something, agitated or glad.
Chin-up
Birds, even if not all, behave like that as a symbol of willing to be petted. Some birds that enjoy having their necks scratched lower their heads deliberately to be petted. Others slowly scratch their heads with their foot to connote they are ready to be petted.
Nape Feathers Up
The bird is either taking care of its territory or is being agitated. Do not handle the bird till it calms down, chiefly if the bird is strutting and pinning its eyes.
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