Hummingbirds

From How to Watch a Hummingbird - Mute Dancers by Diane Ackerman:

While most birds are busy singing a small operetta of who and what and where, hummingbirds are virtually mute. Such small voices don't carry far, so they don't bother much with song. But if they can't serenade a mate, or yell war cries at a rival, how can they perform the essential dramas of their lives? They dance. Using body language, they spell out their intentions and moods, just as bees, fireflies or hula dancers do. That means elaborate aerial ballets in which males twirl, joust, sideswipe and somersault. Brazen and fierce, they will take on large adversaries -- even cats, dogs or humans.

The rest of the essay is worth reading.