Responses of the Skinks, Eumeces fasciatus and E. laticeps, to Airborne Conspecific Odors: Further Appraisal

Abstract

Approach responses of the skinks E. fasciatus and E. laticeps to sources of airborne conspecific chemical cues were studied in a y-maze olfactometer. At an air speed of 10 km/h, neither postreproductive males, postreproductive females, nor testosterone-treated males approached or avoided conspecific odors significantly more often than a control odor (air). These results differ radically from those obtained in an earlier study at much higher air speed (180 km/h). The appar- ently contradictory results may reflect the induction of alternative motivational states by differ- ences in experimental conditions. At the combination of low temperature and high wind speed in the earlier study, skinks may have responded to an aggregation pheromone. Aggressively or sex- ually motivated skinks may respond primarily to contact pheromones rather than airborne con- specific chemical cues. This hypothesis is suggested by the failure of reproductively active skinks either to approach or avoid airstreams bearing conspecific odors and by direct touching of the bodies and odor trails of conspecifics by the tongue.