The birds do it. And the bees do it. Parrots do it. Apparently even hummingbirds do it! Masturbate that is. We caught this male Anna's Hummingbird masturbating on our hummingbird feeder rail. He puffed himself up like a blowfish to nearly twice his normal size. And he kept doing it. For something like ten minutes. It finally dawned on us we should get the video camera out. And we still managed to record the last minute of it.
Wikipedia notes that many animal species masturbate. According to Wikipedia:
Many birds masturbate by mounting and copulating with tufts of grass, leaves or mounds of earth. . .
We can add hummingbird feeder rails to that list!