ECOLOGICAL CORRELATES OF POPULATION AND INDIVIDUAL VARIATION IN ANTIPREDATOR BEHAVIOR OF 2 SPECIES OF DESERT LIZARDS

Antipredator behavior was measured in four populations of zebra-tailed lizards (Callisaurus draconoides) and two populations of greater earless lizards (Cophosaurus texcanus). Lizards were approached in the held, and five measures of wariness were recorded. Callisaurus had significantly greater approach distance and greater final distance than did Cophosaurus. Among populations of Callisaurus, lizards were wariest at the site with the least plant cover. Within populations, air temperature, the directness of the observer's approach, and the lizard's distance to nearest cover when first sighted had significant direct effects on flight behavior based on path analysis. Windiness and time of day had significant direct effects and indirect effects through their relationships with air temperature and distance to cover. Path analysis indicated no one variable with great overall influence on antipredator behavior in these lizards but rather a combined influence of several environmental factors.