Polarization Vision in Birds

Birds have a well-developed visual system adapted to their mobile lifestyle including flight as a mode of transport, diverse mating systems including advanced sexually selected plumage colouration and ornamentations, and a variety of foraging habits. The importance to detect light of different wavelengths is clear from the ecological adaptations present in birds, but there is still limited support from neurophysiological work on how the light information is detected and proceeded in photoreceptors and integrated in brain areas. Especially, detection of polarized light has received some support from experimental work by conditioning and studying compass calibration and orientation in circular cages, but still lacks understanding on the functional mechanisms and what photoreceptors are involved in the polarization detection of bird eye. Future work should include a combination of experimental work and neurophysiological methods to reveal the underlying physiological mechanisms and how they are deployed in different behavioural tasks.