The Elf Owl (Micrathene whitneyi) is a member of the owl family Strigidae, that breeds in the southwestern United States and Mexico. It is the world's lightest owl, although the Long-whiskered Owlet and the Tamaulipas Pygmy Owl are of a similarly diminutive length. The mean body weight of this species is 40 grams (1.4 oz). These tiny owls are 12.5 to 14.5 centimetres (4.9 to 5.7 in) long and have a wingspan of about 27 cm (10.6 in). Their primary projection extends nearly...