We often think of owls as fairly large birds that are capable of eating mice and larger prey. The smallest owl, appropriately named, is the Elf Owl. It is less than six inches tall, with a wingspan of 13 inches, and weighing one and a half ounces. It is speckled gray with a brown facial disk and green eyes, covered by white “eyebrows.” This short-tailed owl’s call is pew pew, like a high-pitched bark or a meowing sound more like a cat. What does a sparrow-sized owl eat? Insects are its usual prey although small birds may be taken. This is an owl of the southwestern deserts in Arizona, New Mexico, and adjacent Mexico where they winter (1).
The Elf Owl is a desert bird and it takes advantage of the characteristic plant of American deserts, the cactus, especially the giant saguaro. Actually, it needs the help of another bird in this process, the Gila Woodpecker. The woodpecker chisels its way into the cactus to search for food and to make a nest cavity. These abandoned cavities are the favorite nest sites for the tiny owls, where they lay their three or four white eggs in May. Where there are waterways and oak or cottonwood trees, these provide alternative nest cavities, and, as with most owls, both parents care for their young. These tiny owls and their young may themselves be subject to predation. They may feign death when approached and do not fight would-be predators, rather flying away if their faint does not work.
Elf Owls begin their activity right at dusk, hunting until dawn, and are notably tame (2). Owls in general, being active in dim light, need visual adaptations to concentrate light on the retina, the photosensitive layer of the eye. In owls this is partly accomplished by having a tube-shaped eye that concentrates all the light on a small patch of retina, so there is adequate light to stimulate the rod-shaped sensory cells.
The scientific name of the Elf Owl is Micrathene whitneyi. The second part of the genus name, “athene,” refers to a Greek goddess, Athena, the goddess of wisdom. Owls have long been reputed to be wise, probably because of their large, forward-facing eyes, making them look almost human. What owl eyes do provide is not wisdom but excellent night vision and binocular vision, hence good depth perception (3).
There are other very small owls around the world. The Ferruginous Pygmy-Owl shares part of its extensive range with the Elf Owl in Arizona. The Little Owl is another small owl, about nine inches in length, that lives in the Middle East and even is mentioned in the Bible as being unclean, along with several other owls and raptors. The Burrowing Owl of the western prairies and deserts of the U.S. is nine inches in height and is the only owl that nests underground, in old prairie dog burrows. Both the Little Owl and the Burrowing Owl share in the wisdom mythology with the Elf Owl, both having the genus name Athene. Owls have an aura of mystery around them, and whether small or large are immediately recognizable as owls.
- National Audubon Society: The Sibley Guide to Birds, Alfred A. Knopf, Inc., New York, 2000 by David Allen Sibley
- The World Atlas of Birds, Sir Peter Scott, ed., Mitchell Beazley Publishers, Ltd., London, 1974
- World Book Encyclopedia, 1995 World Book, Inc., Chicago, volume 14, pages 883-886, article by Norman L. Ford
