Two questions:
Why is this loon doing waving his foot in the air?
Is this common behavior for Common Loon?
I watched this family of three loons in Galveston Bay yesterday for about an hour. The same one would wave the same foot around every once in a while. I googled it and found a few other mentions of this behavior, but I didn't find out why they do it.
The inset three photos are the same loon composited together.

