Tail bobbing bird

by Meg R.

I have an approximately six-month old lovebird named Major. He/she loves people around but isn't too keen about being held yet.
Major's tail bobs or pivots even when it is just standing there not making any noise or moving. I call it a bob because it's in the normal bird-tail position like it should be and then it points a bit more downward and all in a steady rhythm. This isn't all day long but usually for at least an hour a day. Other than that Major still hates American Dad and loves So You Think You Can Dance, eats, plays, yells, and stares at all the dogs.
Has anyone seen this before?