ECOMORPHOLOGY, PERFORMANCE CAPABILITY, AND SCALING OF WEST-INDIAN ANOLIS LIZARDS - AN EVOLUTIONARY ANALYSIS

Studies of ecomorphology - the relationship among species between morphology and ecology - contain two implicit and rarely tested hypotheses: (1) that morphological differences among species result in differences in performance capability at ecologically relevant tasks, which, in turn, produce differences in behavior and ecology; and (2) that morphology, performance capability, ecology and behavior have evolved synchronously. I tested these hypotheses using the Anolis lizards of Jamaica and Puerto Rico. I measured morphological and performance variables on recently caught lizards. Movement, display rate and microhabitat measurements were made on lizards observed in the field. Body size explained most of the variation in morphology and performance ability, but was not correlated with the ecological or behavioral variables. When the effect of body size is removed from the morphological and performance variables, the ecomorphological hypotheses were confirmed. Species that were similar morphologically were also similar in performance ability, ecology, and behavior. Evolutionary changes in morphology, performance, and ecology and behavior (ecobehavior) were correlated. The morphology-ecobehavior comparison revealed that: long-legged, heavy-bodied lizards jump farther in nature, jump and display more often, walk less often, and use wide perches that are distant from the nearest available perches; and that species with many subdigital lamellae perch lower, use narrower supports, and walk more frequently. Inclusion of performance parameters revealed a relationship, in agreement with biomechanical models, between body proportions and running and jumping capability; in turn, performance capability related to locomotor patterns and microhabitat use. Despite the relationship between lamellae number and ecobehavioral variables, clinging performance did not contribute to the correlations with either morphology or ecology.