HABITAT CONSTRAINTS ON THE BEHAVIOR, MORPHOLOGY, AND COMMUNITY STRUCTURE OF ANOLIS LIZARDS

A conceptual model of Anolis-habitat interactions is proposed to explain the existence of the series of Anolis ecomorphs in the Greater Antilles. The use of perches, type of movement among perches and the morphology of 7 spp. of Anolis lizards [A. coelestinus, A. cybotes, A. distichus, A. hendersoni, A. koopmani, A. monticola and A. semilineatus] from 2 sites in Haiti were compared. Movements of anoles through the habitat are assumed to be constrained more by the dispersion of perches rather than the characters of the perches themselves. The habitat is viewed as consisting of 3-dimensional structural matrices of perches differing primarily in the diameters, lengths and distances apart of the perches. Species occupying divergent types of perch matrices differ in the rapidity of moves on surfaces, the frequency of jumps between surfaces and the distances jumped between surfaces. These species can be separated into jumpers, runners and crawlers based on movement type and various body and limb proportions. The horizontal and vertical distribution of each species within a habitat gradient coincides with the distribution of the particular perch matrices to which the species is adapted. The varying degree of restriction imposed by perch matrices may have important evolutionary implications, particularly for the dispersion of size classes within the habitat and hence for species'' exploitation strategies. Applications of this approach to arboreal primates and foliage-gleaning birds are suggested.