Thermal dependence of defensive behavior in a lizard

Response to an attacking predator depends on physiological state in the sand dune inhabiting agamid lizard Agama savignyi. At high body tempera- tures, which facilitate sprint per- formance, these lizards respond to human predators by running away at high speed; but at lower body temperatures, which inhibit rapid locomotion, the lizards rarely run, and instead display vigorously and defend themselves aggres- sively. Defensive behaviors include an inflated upright posture, tail lashing, bared teeth and fangs, and persistent biting. This shift from flight to fight is presumably adaptive because cold lizards would have little chance of out- running and out-maneuvering predators.