A wake-up call for sleepy lizards: the olfactory-driven response of Tiliqua rugosa (Reptilia: Squamata: Sauria) to smoke and its implications for fire avoidance behavior

Abstract

Many reptiles occur in landscapes that are prone to fire, yet limited information is available on the cues these species use to detect approaching fires or their immediate and preemptive behavioral responses to fire stimuli. Here, we describe the behavioral response of ten captive sleepy lizards (Tiliqua rugosa) that were inadvertently exposed to light smoke. Proportionately, significantly more individuals that were exposed to smoke exhibited increased activity, including swift pacing, repeated escape behaviors, and rapid olfactory-related tongue-flicking than those that were not exposed, which did not exhibit any such changes in activity or behaviors. Additionally, of 14 reptile species housed in the smoke-affected area, T. rugosa was the only species to exhibit a noticeable behavioral response. Since there were no visible flames, sounds of fire, reductions in light levels or visibility, or increases in temperature, these observations suggest that T. rugosa detects smoke through olfaction. Moreover, because most individuals were captive-born and, therefore, naive to smoke or fire, this response likely represents an adaptive innate behavioral response of the species. We discuss these findings in the light of fire avoidance behavior in Tiliqua and reptiles in general.