Systematics of the Anoles of San Andrés and Providencia Islands, Colombia.

A systematic review of the anoles (formerly known as Anolis concolor) of the western Caribbean islands of San Andres and Providencia, Colombia, indicates that each island population forms a distinct species. The two species differ from each other in size, arrangement of cephalic scales, number of subdigital lamellae, color of the dewlap and venter, and habitat utilization. The San Andres population should be known as Anolis concolor Cope, and the Providencia species as Anolis pinchoti Cochran. Anolis concolor is typical of single-anole-island species, being sexually divergent in size and habitat occurrence. Anolis pinchoti is smaller, and the sexes share the same habitat. Hypotheses considered to explain this condition were effect of geographic position, "failed invasions", predation by other lizards, and the possibility that A. pinchoti is a very recent colonist.