Meeting Abstract
Homing is common in species that travel back and forth between different patches of habitat. However, one might not expect to find this behavior in species characterized by territoriality and limited dispersal. Here we report on experimental homing behavior in Anolis gundlachi, a territorial lizard endemic to the mountainous rain forests of Puerto Rico. Wild, male A. gundlachi returned to their territories when experimentally displaced 40, 80, or 120m in a random direction and without access to local cues. Some individuals were tracked using radio-telemetry and homed within 24 hours of displacement, along nearly straight paths to their destinations. The directness of the routes, coupled with the results of a computerized random walk simulation, suggests that lizards do not return to their original perches merely by chance. However, an initial series of experiments failed to identify the mechanism(s) underlying homing behavior in this species. Specifically, the removal of polarized light cues to the parietal eye and the disruption of localized magnetic fields did not reduce the probability of homing from 40m. Future work is needed to determine whether these results hold for greater displacement distances. Regardless of the homing mechanism, we argue that the ability of A. gundlachi to home despite the extraordinarily low probability of ever finding themselves such distances from their territories likely reflects both the value of territory ownership and strong selection for spatial memory in species that live in complex three-dimensional habitats. If true, homing ability may be more common than current empirical evidence indicates.
