Abstract
Perch height selection was studied in juvenile western fence lizards (Sceloporus occidentalis) and sagebrush lizards (Sceloporus graciosus) in the field and in the laboratory. In nature juvenile S. occidentalis were more arboreal than were juvenile S. graciosus. In laboratory experiments with lab-reared 3-4 wk old lizards, S. occidentalis perched off the ground more frequently. Differences between these two species in habital preference are inferred to be at least partly innate, and emerge at an early age. Within each species, juveniles from different field populations differed in habitat use in the wild: lizards were more terrestrial at higher elevations. However, lab-reared juveniles from different populations of each species did not differ in laboratory tests of perch selections. In S. occidentalis there was evidence of individual variation in perch selection in the laborabory, but no among-family variation was detected.