Elf Owl (Micrathene whitneyi) with prey, flying to its nest in a cactus. The Elf Owl is a tiny, short-tailed owl of the southwestern United States and Mexico. These nocturnal birds sit fairly erect and have a knock-kneed stance. Flight is somewhat bat-like, but not as erratic. The Elf Owl inhabits arid deserts overgrown with Saguaro Cacti, thorn scrub, and mesquite or deciduous riparian woodlands from 2,000 to 7,200 feet. They are entirely dependent on woodpecker cavities for nest sites, both in cacti and deciduous trees. Cavity entrances range from 10 to 33 feet above ground. Santa Catalina Mountains, Arizona.