Men might puff out their chests when attempting to stand up to a potential rival, but male owls defend their territory by lowering the pitch of their hoots to try to make themselves sound bigger than they are, researchers at Sussex University have found.
Animal communication scientists Loic Hardouin and David Reby from the department of psychology have demonstrated that the heavier the male, the lower the pitch of his hoots.
They discovered, after recording several hundred hoots from 17 males on the isle of Oleron, that male owls defending territory against rivals perceived as bigger pitch their hoots slightly lower to mimic the sound of a heavier bird to discourage potentially dangerous challenges.