My 9 yr old female IRN displays a 'foot shaking' behaviour, and I don't seem to be able to find anyone else that has written about this topic.
She has done it for years, but I guess I just thought it was part of the breed's nature and never investigated it further. But I am now wondering if anyone would have any input on this!?
On an almost daily basis, she will hold her left foot up (always her left), and shake it upon approaching an object. The object could be an old or new toy, or even a food given as a treat. She seems to do it a lot to one of her toys, a practice golf ball. But she also seems to do it a lot to one of the castor wheels on the bottom of her cage when she is on the ground. She even does it to strawberries!!
Does anyone know what the reason might be for this? Is it a sign of affection, or is she intimidated/frustrated? Sometimes when she does it to her golf ball she will get angry at it afterwards (as it is a hollow practice ball with holes in it, she will pick it up with her beak and throw it across the room). But she doesn't display this behaviour with food.
If anyone has any comments, I would really appreciate it! Thanks!!
I have heard of similar behaviours. But not directly shaking at an object/toy. Sounds similar to what my 11 year old boy does and has been doing it for years. Typically, his foot starts off 'waving' or shaking (closed like a fist) and he talks to it like hes talking into a microphone, but strangely he always gets angry at it and attacks it as his own claw 'tickles' his head. Its like it has a mind of its own because we he stops he looks at it strangely as if to say 'what just happened?' 
Odd!