Abstract
Black iguana are eaten by human and other predators in Costa Rica. The importance of eye size on avoidance and recovery behaviour of black iguana was examined using an approaching person as the stimulus. Iguanas moved and ran earlier when the approaching person wore a large eye mask than when she wore a smaller eye mask. Iguana response did not vary during the tests as a function of snoutvent length, but response variables were generally correlated. Black iguana clearly moved and ran earlier in response to a large compared with a small eye, indicating they perceive and monitor this feature of predators.