The Role of Hearing in the Brown Anole (<i>Anolis sagrei</i>, Polychrotidae): A Behavioral Perspective

All animals are likely to encounter a predator during their lifetime. Prey can reduce their risk of predation by recognizing dangerous situations and modifying their behavior accordingly. Many animals are known to utilize auditory predator cues to assess risk. However, lizards have historically been assumed to emphasize vision to assess risk because most species do not vocalize and, therefore, do not themselves communicate using sound. I conducted a field experiment to investigate the ability of the brown anole (Anolis sagrei, Polychrotidae) to 1) use auditory cues to evaluate predation risk and 2) distinguish between threatening and non-threatening avian calls (Chapter I). Next, I explored the importance of sound pressure level of auditory cues to assess the proximity of a predator under natural conditions (Chapter II). Finally, using a laboratory experiment, I compared lizard responses to the calls of a known sympatric predator and three distantly related unknown allopatric predators to further understand the role of familiarity with calls or similarity in call characteristics in driving antipredator behavior (Chapter III). My results indicate that brown anoles not only utilize auditory cues to assess predation risk, but also that familiarity with cues may be an important factor in auditory predator discrimination. My research provides a greater understanding into the sensory mechanisms these lizards use to assess their surrounding environment and, importantly, provides a greater understanding into the proximate mechanisms by which animals recognize auditory predator cues.