Because we tend to think of owls as being nocturnal in their habits, we also assume that they must have well-developed senses of hearing and vision. Interestingly, the visual and auditory sensitivities of predominantly nocturnal owls, such as the tawny, are no better than our own, though they do outperform diurnal birds by quite a margin.
For owls living in open country, there is sufficient natural light at night to allow them to forage successfully by sight, but for woodland owls, the gloom and structurally diverse nature of their habitat makes this more difficult, forcing them to rely more on sound.
Woodland owls often perch-hunt (looking and listening for prey) and follow regular routes through the trees, effectively flying blind, guided towards noisy quarry by acoustic cues. Owls are silent fliers thanks to their specially designed wing feathers that muffle the air, allowing them to swoop down unheard.
Even for a diurnal woodland owl, hearing may be the more important sense for locating prey (think of owls pouncing on voles foraging under the snow). Vision, however, is also essential for targeting a meal, especially when it comes to judging distance.
Main image: Barn owl © getty Images