Orientation and homing behavior as a measure of affinity for the home range in two species of Iguanid lizards

Abstract

AbstractThe relationship between home range affinity and homing ability was studied in Phrynosoma douglassi and Sceloporus graciosus in southeastern Idaho. Movement patterns for P. douglassi were typical of an animal moving from one site of activity to other sites, whereas S. graciosus movements were typical of an animal using a single site of activity. Only S. graciosus was able to orient towards the home range when displaced, indicating an affinity for this site. Adult S. graciosus oriented and homed more consistently than did juveniles. P. douglassi did not orient homeward when displaced and returned less frequently than did S. graciosus. Recapture locations along with data regarding homeward orientation and homing indicate that P. douglassi has a lesser affinity than does S. graciosus for the home range. Some gravid females of both species left the home range to deposit eggs or young and later returned. Use of areas outside the home range for egg-laying and birthing and movements out of the home range resulting from chases by predators may represent natural means of displacement that select for homing behavior. Because most lizards experience only short displacements during their life histories, long distance homing reported for snakes, turtles, and salamanders is absent.