Detection and Response to Conspecific Chemical Cues by Ornate Tree Lizards (Urosaurus ornatus)

Although many lizard species detect and respond to conspecific chemical cues, variation in this ability among populations of the same species from different habitat types is less well understood. We compared chemoreceptive behaviors and head-bobs in response to conspecific chemical cues by Ornate Tree Lizards (Urosaurus ornatus) between populations from an upland forested habitat and a lowland desert habitat. Under this experimental design, U. ornatus from different habitats performed chemoreceptive behaviors and head-bobs at similar rates. Rate of chemoreceptive behaviors and head-bobs in response to chemical cues deposited by same- and opposite-sex conspecifics was higher than that of cues deposited by the subject in their home tank, demonstrating that U. ornatus has the ability to detect cues from conspecifics. Head-bob rate was also higher in same- and opposite-sex tanks compared to home tanks, demonstrating that chemical cues alter the rate of a social display behavior. Urosaurus ornatus exhibited chemosensory behavior at rates similar to rates reported for this species and lower than those reported for other phrynosomatid lizards, suggesting a lower reliance on chemical cues in social interactions.