Polarization Sensitivity in Reptiles: An Update

Somewhat questionable evidence in support of reptilian polarization sensitivity (PS) has come from field and laboratory observations on the behaviour of a few species of marine and freshwater turtles. More convincing are conclusions based on PS-aided orientation primarily in the lizards Uma notata, Tiliqua rugosa and species of the genus Podarcis. It is suggested that submersed hunters like, for instance, sea snakes ought to be included in examinations for PS since contrast enhancement by PS underwater could bestow some benefits to them during food procurement. Moreover, certain terrestrial snakes such as rainbow boas, sunbeam and indigo snakes are highly iridescent, and courtship displays in certain species of lizards could also contain signals for which the presence of PS would be advantageous. However, unambiguous polarization signals have not yet been demonstrated in any species. Results based on electrophysiological recordings to demonstrate PS in photoreceptors of the lateral eyes or the pineal organs’ parietal eye are also scant, but a connection between PS and magnetoreception, as in amphibians and birds, is increasingly regarded as a feature present in numerous reptilians. The earlier literature on reptilian PS has been covered by Horváth and Varjú (Polarized Light in Animal Vision—Polarization Patterns in Nature. Springer, Heidelberg, Berlin, New York, 2004) and Meyer-Rochow (Polarized Light and Polarization Vision in Animal Sciences. Springer:, Heidelberg, Berlin, New York, 2014).