Anole on Anole Violence

Down the hatch. Anolis cybotes eats A. marron. Photo by Luke Mahler.

A few years back I was asked to give a talk to some undergraduate marine biology students studying at the Discovery Bay Marine Lab in Jamaica. I brought a live Jamaican giant anole (A. garmani) to this presentation, and told the students that this species eats just about any other animals it can fit in its mouth – including other anoles. One of the students seemed shocked by this revelation and suggested that “they only eat other anoles in emergencies, right?” This necessitated a little lecture on nature red in tooth and claw that seemed to leave some of the students on the verge of tears. (Presumably readers of this blog already know that whatever concerns organisms might have about inclusive fitness do not extend to the intra-generic level.)

Although anole on anole predation is a well-known phenomenon, most reports involve adults feeding on much smaller juveniles. In the latest issue of Herpetological Review, Luke Mahler and I report an exception to this generality involving predation by an adult male Anolis cybotes on an adult female Anolis marron. With a prey SVL ~60% as large as the predator’s (70mm for the predator v. 45mm for the prey) this observation ranks as the highest predator:prey ratio ever reported for anoles. Given that the A. cybotes failed to fully ingest its prey during the 8+ hours we held it captive, we speculate that this event was at, or perhaps even above, this individual’s prey size limit.