The Owl That Hears Through Snow

A great grey owl can locate a vole under 45 cm of snow, then punch through the crust feet-first at the exact spot.

The facial disc is not decoration. It is a parabolic collector, and the feathers around it can be adjusted like an aperture to focus sound onto asymmetrically placed ear openings — one higher than the other, which gives the bird vertical as well as horizontal localisation.

The result is a strike accurate enough to be made blind, through a snowpack deep enough to bury the bird's own body. It hovers, drops the legs first, and hits a target it has never seen.