The elf owl is the world’s smallest owl, with an average length of just 5 to 6 inches. Despite its tiny size, this nocturnal bird has many unique and fascinating characteristics. The elf owl is found in the southwestern United States, Mexico, and parts of Central America. They inhabit deserts, dry grasslands, and woodlands. The elf owl gets its name from its tiny size and large, pointed ears that give it an elfin appearance. But there’s much more to this pint-sized predator than just its looks.
Appearance
The most obvious unique feature of the elf owl is its incredibly small size. Weighing just 1.5 to 2 ounces, it rivals even the smallest hummingbirds in stature. Its total body length ranges from 5 to 6 inches. In comparison, a great horned owl may be 20 inches tall. The elf owl has gray-brown feathers covered in white speckling on the wings, back and head. Their underparts are a light gray. Prominent whitish eyebrows accentuate their yellow eyes. Their beak is yellow with a black tip. Tufts of feathers on the head resemble ears, adding to the owl’s elfin appearance. Overall their coloration helps them blend into desert trees and scrub.
Habitat
The elf owl inhabits the deserts of the southwestern United States and Mexico. Their range extends from California to Texas, and south into the Mexican states of Baja California, Sonora, and Chihuahua. They are year-round residents within this dry, arid region. The elf owl prefers areas with saguaro cacti, cottonwoods, and other desert trees. These provide cavities for nesting and roosting. During the day, elf owls hide in natural tree cavities or old woodpecker holes. Their small size allows them to use holes as small as 3 inches across. At night they emerge to hunt for insects and small prey.
Diet
Despite its tiny bill, the elf owl is a formidable nighttime predator. Equipped with excellent vision and hearing, they hunt by swooping from a perch to grab unsuspecting prey on the ground. Their diet consists mainly of insects like moths, beetles, crickets, and grasshoppers. They will also eat small rodents, reptiles, and arachnids. An elf owl can eat up to half its body weight in a single night of hunting. They swallow small prey whole and digest everything except feathers, fur, and bones. Leftover pellets containing indigestible parts are regurgitated.
Breeding
Elf owls form monogamous breeding pairs that mate for life. The breeding season runs from March through July. Elf owls nest in natural cavities like woodpecker holes or saguaro cactus cavities. The female will lay 2-3 small white eggs over the course of a few days. She incubates the eggs for about 3 weeks while the male brings her food. Once the chicks hatch they are cared for by both parents. The tiny chicks fledge from the nest in about a month, but remain dependent on their parents for another month or two.
Vocalizations
One of the elf owl’s most unique and identifiable traits is its haunting, musical call. Because they hunt at night, elf owls have many different vocalizations used to communicate in the dark. Their primary song is a long, clear whistle repeated every few seconds. It sounds like “who-who-who-whoooo.” They also make various chattering and chuckling sounds. These help the small owls find each other and defend their territory from rivals. The elf owl’s song carries surprisingly far and can be heard up to a half mile away on a quiet night.
Migration
Unlike many owl species, the elf owl does not migrate. They establish permanent territories as breeding pairs and remain in that area year-round. In winter, elf owls conserve energy by going into torpor. They lower their body temperature and metabolic rate during the night to save energy. This helps them survive on limited food in winter. The elf owl’s small size allows it to drop its temperature by up to 20 degrees Fahrenheit during torpor.
Longevity
For such a tiny bird, the elf owl has a relatively long lifespan. Wild elf owls may live up to 6 years. Owls in captivity have lived over 10 years. Their small bodies have lower metabolism and energy needs, which contributes to their long life compared to other birds. Careful hiding in dens also helps them avoid predation. Main threats to wild elf owls include habitat loss and nest disturbance. As cavity nesters, they are vulnerable to deforestation and development removing old trees and cacti.
Abundance
The elf owl has a large range in the southwestern U.S. and Mexico. However, habitat loss and the cutting of nest sites has led to population declines, especially in the U.S. They are now uncommon to rare in many areas, including California. Overall, elf owls have an abundance ranking of Uncommon. Their total global population is estimated between 50,000 to 499,999 individuals. Conservation measures are needed to protect suitable desert nesting habitat for this tiny owl. Monitoring and creating artificial nest boxes may aid populations.
Subspecies
There are three recognized subspecies of the elf owl:
Micrathene whitneyi whitneyi
This subspecies is found in Arizona, New Mexico, Texas, and Mexico. It is the nominate or original subspecies that the others were split from.
Micrathene whitneyi graysoni
Sometimes called the Sonoran elf owl, this subspecies lives in central and southern Arizona into Sonora, Mexico. It is slightly larger than M. w. whitneyi.
Micrathene whitneyi idonea
Also known as the Baja elf owl, this subspecies is found only in the Cape District of southern Baja California. It is the darkest colored subspecies.
Taxonomy
The elf owl belongs to the order Strigiformes which contains over 200 species of owls. Strigiformes means “typical owls” or “true owls.” It is part of the family Strigidae. The elf owl’s full scientific name is Micrathene whitneyi. They were first described by American ornithologist George Newbold Lawrence in 1867 based on specimens from Arizona. The genus name Micrathene combines the Greek words micro meaning “small” and Athene which is the Greek goddess of wisdom. Their species name whitneyi honors Josiah Dwight Whitney, a prominent American geologist.
| Scientific Classification | Common Name |
|---|---|
| Kingdom: Animalia | Elf Owl |
| Phylum: Chordata | |
| Class: Aves | |
| Order: Strigiformes | |
| Family: Strigidae | |
| Genus: Micrathene | |
| Species: M. whitneyi |
Conservation Status
The elf owl is listed as Least Concern by the IUCN Red List. This means they are not considered globally threatened or endangered. However, certain populations in the U.S., like those in California, are recognized as Endangered by state agencies. Ongoing threats include:
- Habitat loss and degradation
- Development and logging removing old trees and cacti that provide nesting cavities
- Disturbance of nest sites which can lead to abandonment
- Climate change and drought further threatening arid habitats
Conservation priorities include preserving stands of large saguaro cacti, cottonwood trees, and other desert vegetation. Monitoring known elf owl sites and artificial nest box programs may also boost populations. Given its small size and unique desert habitat needs, the elf owl warrants continued observation and habitat management across its range.
Key Facts
- The elf owl is the world’s smallest owl, weighing only 1.5 to 2 ounces and 5 to 6 inches long.
- They inhabit the hot deserts of the American southwest and Mexico.
- Elf owls nest in natural cavities in cacti and trees.
- Their diet consists of insects, scorpions, small rodents, reptiles, and spiders.
- They form lifelong monogamous pairs and live up to 6 years in the wild.
- The elf owl is primarily nocturnal and sleeps in cavities during the day.
- They have long, musical territorial calls that carry far at night.
- They do not migrate and can go into torpor to save energy in winter.
- Habitat loss is the main threat, and populations are declining in parts of their range.
Conclusion
The diminutive elf owl punches above its weight class in terms of unique attributes. Its tiny size makes it the world’s smallest owl, with adaptations like torpor to survive the harsh desert climate. Cavity nesting requirements reveal a fragile dependence on native cacti and trees. Fantastic night vision and a keen sense of hearing equip this pint-sized predator to hunt under the cover of darkness. And that melodious call carries an outsized distance for such a little bird. Unfortunately habitat loss threatens the future of the elf owl in portions of its range. However, its long lifespan and monogamous breeding could provide hope for rebounding numbers if conservation efforts persist. For an owl barely larger than a human hand, the elf owl harbors a wealth of special traits and secrets within its tiny frame.
