The ability to perceive the third dimension of light, i.e., its polarization or alignment of the electric vector, has been well described in a wide variety of animals. Despite of convincing evidence that birds use cues from the skylight polarization pattern for orientation and compass calibration, we know almost nothing about how they can perceive this information. While the polarized light receptors in many invertebrates and some fish species are relatively well studied, birds do not have any obvious receptors in their eyes, thus the question of how they are able to detect polarized light information still remains to be solved.
We investigate the behavioural and functional properties of polarized light sensitivity in birds using a recently developed spatial orientation assay. We train birds to use the axial alignment of overhead PL cues to locate a hidden food source. By manipulating the properties of the polarized light used during the experiments, we can study for example the sensitivity of polarized light vision in birds, allowing us to make predictions under what natural conditions birds are able to use information from the skylight polarization pattern.
Last modified 2 Jul 2013