A barn owl.
barn owl definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
any of a family (Tytonidae) of owls, esp. a widely distributed species (Tyto alba), usually brown and gray with a spotted white breast, found chiefly in hollow trees or barns, that feeds on rats and mice
barn owl definition by American Heritage Dictionary
A predatory nocturnal bird (Tyto alba) having a white, heart-shaped face, buff-brown upper plumage, and pale underparts, often nesting in barns and other buildings. Also called monkey-faced owl.