Owls are the only truly nocturnal avian raptors and have evolved several unique adaptations to perfectly fill this role. For example, their unique large tubular eyes, packed with light-sensitive cells, enable owls to operate in almost total darkness, while their remarkable auditory system allows them to operate in complete darkness. This unique and complex auditory system is a combination of specialised feathers forming a parabolic facial disc, adjustable operculum, or flaps and, in some spec...
