Polarization Sensitivity and Insensitivity in Bats

Non-migratory female greater mouse-eared bats (Myotis myotis) use celestial polarization at sunset to calibrate their magnetic compass used for homing. Anatomical, physiological and behavioural investigations should elucidate how these bats perceive polarized light and how they use it for orientation. In choice experiments, migratory Nathusius’ bats (Pipistrellus nathusii) did not respond to linearly polarized light stimuli and did not use sky polarization as the primary calibration reference of their magnetic compass. Further experiments should test if these bats depend on polarized light for orientation during their non-migratory period.