The elf owl, or micrathene whitneyi, is the world's smallest species of owl. They take their Latin name from Josiah Dwight Whitney, a 19th century geologist in the United States. Other names for the elf owl include the dwarf owl, Whitney’s owl, Whitney’s elf owl and the Texas elf owl. In Mexico, it is called enano.
A typical adult elf owl is measures about 5 inches (13 cm) long. Weighing about 1 to 1.5 ounces (30 to 40 grams), it is roughly the size of a sparrow. A wingspan of about 9 inches (23 cm) is typical.
Elf owls are grayish brown, dappled with brown and white spots. Unlike many other species of owl, the elf owl’s round head does not have ear tufts. It does, however, have distinctive white eyebrows over yellow eyes and a small gray beak.
Native to the deserts of the southwest U.S. and Mexico, elf owls often make their homes near stream beds or other water sources. They nest in abandoned woodpecker holes found in sycamores and oaks, but they are best known for nesting in giant saguaro cacti. Owls native to northern regions migrate to Mexico for the winter.
Males select nesting sites and then attempt to attract a female. Occasionally, there is competition for nests, both with other owls and with the woodpeckers who made the nests. In April or May, the female elf owl lays one to five eggs, which hatch in about three weeks. Within a month, these hatchlings are able to fly and hunt for food themselves.
Lacking the strength of larger owls, elf owls typically hunt arthropods such as spiders and insects. Grasshoppers, moths, scorpions, locusts, centipedes and beetles are common prey. Elf owls only rarely attack larger animals such as mice, birds or lizards.
Like all owls, elf owls are nocturnal and hunt at night. Keen night vision and acute hearing help to make elf owls effective hunters. They are able to fly silently and possess excellent maneuverability in the air. Although they are able to forage on the ground or in a tree, they prefer to snatch up prey while in flight.
When faced with larger predators, the elf owl usually will attempt to flee. By nesting in tall trees and cacti, they are able to avoid most ground-based predators such as snakes, coyotes and bobcats. When an elf owl is captured, it often will “play dead” until the attacker loses interest.