The researchers used advanced mathematical tools in a wind tunnel to show that the role of the fringe on owls’ wings is to negate something called the ‘Flowes William and Hall effect’. The porous elastic fringe filaments are a much softer ‘sound scatterer’ than a sharp rigid edge. The role of the complex feather structure is more of a mystery but the collaborators have been able, to some extent, to replicate its effect in the laboratory. “What appears to be crucial is the way that the fine hairs form a ‘canopy’ perhaps shielding the basal surfaces of the wing from pressure fluctuations in the turbulent air flow. The intricate structure of owl’s wings was noted more than 300 years ago by Francis Willughby, the polymath who compiled one of the world’s first comprehensive and analytical ornithologies. Several species of owl feature in Willughby’s Ornithologia libri tres which was published by his more famous friend and colleague, the naturalist John Ray.