In terms of body lengths per second, A diving hummingbirds flies faster than a fighter jet, says a researcher from the University of California, Berkeley, U.S.A. Christopher Clark filmed the courtship rituals of male Anna's hummingbirds and calculated that when swooping to impress females, "the feathered acrobats reached speed of almost 400 body lengths per second". Such a speed is comparatively "greater than that of a fighter jet" at full throttle, says Clark. When pulling up at the end of its dive, the bird is subject to a force ten times the pull of gravity . more than fighter pilots can stand without losing consciousness.