One doesn't usually think of birds playing, but I am sure they do. I was out hanging laundry a little while ago, and saw two downy woodpeckers chasing each other around a tree and between trees. Also saw a small hawk (Cooper's or broadwing?) zipping around. Yesterday I caught sight of a red-tail hawk wayyy up in the sky, and I would swear it was doing aerial tricks up there, just for fun.
There was a titmouse in another tree, calling back and forth with a titmouse on the other side of the yard, and I have a large flock of goldfinches that make a lovely background song. I know they are there, but they are so high in the trees and so small and brown that I cannot see them except when they come down to the feeders.
I think maybe chickadees are my favorite songbird, though. They don't have the most beautiful song, or the most striking plumage, but they seem so solid and straightforward. Their colors are definite, and they seem to know just what they are doing. We have loads of black-capped chickadees around here. They can go into controlled hypothermia when winter gets really cold, and this conserves their energy to get them through the frigid weather. How's that for planning on Mother Nature's part?!