Divergence of visual motion detection in diurnal geckos that inhabit bright and dark habitats

Abstract

Recent studies of the sensory drive hypothesis suggest that communicative signals evolve readily whereas hange in sensory perception is more constrained by the demands of the physical environment.2. Here, we find that diurnal Sphaerodactylus macrolepis geckos collected from dark, forested habitats were best able to detect motion in very dim light (< 10 lux), whereas geckos collected in brightly-lit coastal areas exhibited optimal motion detection at a much brighter light range 200-300 lux. 3. Motion detection by geckos from both habitat types declined as light intensity increased above 300 lux. These differences were observed after the lizards had been living in a common laboratory environment for 1 full year and are hence unlikely to be due to acclimation effects.4. Light conditions for optimal isual performance match the light conditions of the natural habitats in which the lizards are found. Our results support the suggestion that visual performance may evolve quickly and that the sensory drive process may be best described as repeated coevolution between signals and receiver sensory systems.5. Thus, for animals that inhabit wide ranges of isual habitats, the sensory drive process may potentially act differently on separate visual response properties, resulting in diverse levels of variation and divergence in visual performance and communication systems. © 2009 British Ecological Society.