Food acquisition modes and habitat use in lizards: questions from an integrative perspective

Abstract

Introduction The four basic tasks, EPM, FAM, and habitat One useful theoretical focus in evolutionary ecology is that an animal has four basic, autecological tasks: (1) find, acquire and utilize food; (2) avoid, evade, and deter predators; (3) cope with abiotic stresses and avoid abiotic extremes; and (4) acquire mates and reproduce. An integrative understanding would require knowing the relative influence of each of these tasks on the ecology of an individual, on the population, and on the evolution of higher taxa. In addition, it would be important to identify and understand how behavioral traits (ethotypes), physiological traits (physiotypes), and morphological traits (morphotypes) of animals are adapted to each of the four basic autecological tasks (Fig. 15.1). I refer to the sum of these traits as the EPM (the ethophysiomorph or ethophysiomorphotype). Among the four basic autecological tasks, food acquisition and utilization may be the primary, albeit sometimes indirect, cause for salient features of ethotypes, physiotypes, and morphotypes (and thus EPMs) of lizards and other animals (Anderson and Karasov, 1988). The classic, general vertebrate mode of food acquisition as mobile, ectothermic predators on invertebrates continues to dominate in lizards (basal level in Fig. 15.1), and many features of lizards appear to be related to the basic autecological task of food acquisition (Pianka and Vitt, 2003). The set of physiological, behavioral, and morphological characteristics (the EPM) that are integrally involved in the search, detection, capture, and eating of food, may be considered an adaptive syndrome (Eckhardt, 1979) that I refer to as the “food acquisition mode,” FAM. An adaptive syndrome is a coordinated set of characteristics (adaptive traits) associated with an issue of overriding importance (a core adaptation) to an organism (Eckhardt, 1979).