Locomotor correlates of ecomorph designation in Anolis: an examination of three sympatric species from Jamaica

Abstract

Scaling of locomotor structures (limb length, scansor area, and intergirdle distance) in three Jamaican Anolis species (A. garmani, A. grahami, and A. opalinus) is examined. Reference to structural-niche use patterns and partitionings typical of these three species is made. Each species represents a separate Anolis ecomorph, differing from the others in adult size, shape, and structural niche. All are part of a single intra-island phyletic radiation. Allometric models indicate that intra- and inter-specific differences in proportion of locomotor structures are not necessarily ontogenetically invariant, but that all three species ontogenetically arrive at, or have attained, the differences in proportion typical of their adult sizes. Differences in adult proportion between two species are not functions of body size alone but are the products of different scaling trajectories. No intraspecific differences in structural-niche use are documented, but interspecific differences are well defined: the greater the number of differences in locomotor scaling between two species, the greater the structural-niche partitioning. We suggest that the locomotor structure scaling patterns observed in these three species are typical of the ecomorphs that they represent. Analogous ontogenetic patterns of development should be displayed by independently derived representatives of these ecomorphs from other Greater Antilles islands.