<h as the Barred Owl or Great Horned Owl here in Minnesota) primarily hunt small mammals such as voles, rabbits, or field mice, and these goofy looking fluff balls are actually highly derived flying death pillows. During the long winters of Minnesota, predators who don’t migrate, such as Barred Owls, must continue to feed. Hunting in winter is a particularly difficult task for predators that feed on small mammals, because dealing with snowpack becomes a complex challenge. Many small mammals prefer to travel under the snowpack, rather than on the surface where the contrast between the white snow and their darker coats may attract danger. This space under snow is called the subnivean zone, and many mammals utilize this space for shelter and warmth. What does this mean for predators? What about for aerial predators? What about for aerial predators that are predominantly nocturnal hunters? Long story short, it means you’ve got to have some tricks up your sleeve.
Most owls posses asymmetric ear openings. Morphologically this means that the opening to the ear canal is not on the same part of the skull (i.e. one hole is high on the skull and the other is lower). Humans can perceive location along a horizontal axis by sensing the minute time differences in which a sound reaches one ear versus another. By having ear openings on opposite sides of their heads, owls can perceive location along the horizontal, as well as depth. This means that owls can hear exactly where a small mammal is located, as well as how deep under the snow or in the snow the creature is. This level of accuracy allows an owl to dive into snow feet first, and efficiently snag prey. The asymmetric ear is so advantageous for owls, that it is believed to have arisen 5 separate times within the order. Long story short, owls are the laser guided missile of the animal kingdom.