No Evidence for Sex-Specific Visual Acuity in Anolis aquaticus

Authors: Samantha Garnsey, Janelle Talavera, Lindsey Swierk

Field of Study: Science, Technology, Engineering, and/or Math

Program Affiliation: Summer Scholars and Artists Program (SSAP)

Faculty Mentors: Lindsey Swierk

Easel: 68

Timeslot: Midday

Abstract: Sex differences in sensory perception are widespread among animals, driven by sex-specific reproductive challenges. Males and females often exhibit different sensory abilities, such as in visual acuity; for example, in Heliconius butterflies, males exhibit greater visual acuity due to their mate-seeking behaviors. This study examined this idea in Anolis aquaticus, a semi-aquatic lizard with sexual dimorphism. Males court females using a colorful throat fan (dewlap), which females use to select mates. It is predicted that females will have greater visual acuity than males, given their reliance on visual signals for mate choice. A custom-built apparatus was used to test 45 A. aquaticus (17 females, 28 males) responses to increasingly conspicuous stimuli. No significant sex differences were found in visual acuity or overall responses to stimuli. These results suggest that visual acuity does not differ between sexes in anoles and that other ecological factors (e.g., prey identification) may drive the evolution of visual acuity.