WHY DO LIZARDS DO "PUSH-UPS"?

Lizards use various displays, including "push-ups" (see short movie), head-bobs, dewlap displays, body inflation, and gaping, to signal dominance or courtship. Some signals are only for members of the same species, while the same or other signals are used on other species. Using these species-specific, ritualistic signals reduces the need for outright combat and helps individuals recognize other members of their own species for mating.