The long-eared owl (Asio otus), also known as the northern short-eared owl, is a medium-sized, slender owl belonging to the family Strigidae. It is a widespread species, distributed extensively across Europe, Asia, the Middle East, North America, the far north of Africa, the Canary Islands and the Azores.
The adult short-eared owl is a brownish-grey owl with an orange facial disc, whitish underparts with dark streaks, a brown back, and long ear tufts that distinguish this species from other owls when perched. The species is sexually dimorphic, with the female being larger and more colourful than the male.
This owl can weigh between 220 and 435 grams and is between 35 and 40 centimeters tall. It has large, rounded wings with a wingspan of between 90 and 100 centimeters, which can be noticed in flight. Juvenile birds have soft feathers, giving them a fluffy appearance and a distinctive “V” shaped marking on the face.
There is a marked difference in appearance between the North American and Eurasian populations. Birds found in North America are rather dark, appear more streaked and mottled, and have yellow eyes. In contrast, Eurasian birds are paler all over the body, but mainly in the face and reddish eyes.
Long-eared owls are a quiet species compared to other owls, and call predominantly during the breeding season when they produce a collection of songs and calls that serve a variety of purposes. The typical male call can be described as a resounding “woop” repeated every two to four seconds in a series of up to 200 notes.
The sound produced can be heard over a kilometre away. The female gives a high-pitched call at the nest, which sounds like the bleating of a lamb. Males and females also produce alarm calls that range from dog-like barks to cat-like meows. When an owl is restless, it quickly makes a popping sound by snapping its jaws shut.
Both sexes can beat their wings while flying, which produces a whip-like sound. Young birds also make begging calls.
Long-eared owls reside primarily within their breeding range, but birds living in the northern sections of their range are largely migratory, moving south during the fall. Owls may respond to decreased food availability by becoming nomadic and moving to areas where food is available.
Birds of the World distribution map
Short-eared owls are found in areas with a mix of tree cover, with ideal habitat being wooded areas with adjoining shrubland or open grassland. Wooded areas consist mainly of coniferous and deciduous forests with watercourses and windbreaks.
The species has a wide elevation range, from sea level to nearly 2000 m above sea level. The owls require different biomes for roosting and hunting. They roost during the day in the thick vegetation found in forests and hunt in adjacent open scrub and grassland at night.
Short-eared owls feed primarily on small mammals. Mammals include voles, shrews, mice, young rabbits, kangaroo rats and gophers. Small birds are sometimes also preyed upon by owls.
Birds are caught on the ground or in low vegetation while resting. Other animals recorded as prey include bats, weasels, moles, chipmunks, squirrels, lizards and snakes.
They can catch prey weighing up to 100 grams, but most prey weigh less than 60 grams.
Long-eared owls are nocturnal creatures, so they are most active at night, when they spend most of their time hunting. During the day, they perch in trees, often against the trunk. Owls are rarely active at dusk, but they hunt when they need to capture other food to feed their young.
Owls hunt by flying back and forth, near open ground. In some cases, owls may hover over their prey or hunt from a perch, especially during strong winds. They detect prey using both sight and hearing. The owl pounces when it finds prey, swooping down and grabbing the animal with its talons.
The animal is killed by biting the back of the skull and the prey is usually swallowed whole. Hunting usually takes place in open areas, but they are known to sometimes hunt under the canopy of trees in areas with less tree cover.
Long-eared owls breed during the boreal spring and summer months, from February to July. During the fall and winter, owls congregate and establish roosting groups of up to 100 individuals. This species is monogamous and courtship usually begins in late winter, when males begin displaying to females before the birds disperse.
During the courtship phase, males engage in aerial courtship displays, which involve flying in a zigzag pattern over the nesting habitat and flapping their wings intermittently between glides.
Short-eared owls are not known to build their nests, so they commonly use stick nests in trees made and abandoned by other bird species, such as crows, magpies, ravens, and hawks. On occasion, owls may use abandoned squirrel nests, cliff cavities, tree cavities, or even nest on the ground.
Nesting pairs can sometimes be found within 15 metres of each other, which are considered loose colonies. The nest is about 6.5 centimetres deep and 22 centimetres wide. Females only produce a single brood during the season. Broods typically consist of five to six white eggs, but females may lay anywhere from two to ten eggs. Eggs are 3.8 to 4.4 centimetres long and 3 to 3.5 centimetres wide. Eggs are incubated for 26 to 28 days before hatching.
The female remains at the nest during the incubation period and the male catches prey to return to the female. Once the chicks hatch, the male is solely responsible for bringing them food and continues to bring food to the female, who remains with the chicks. At the end of the brooding period, the female leaves the nest to hunt and help the male bring additional food to the chicks. The owlets leave the nest three weeks after hatching and move to the surrounding branches. They are known as “branchers” as they no longer live in the nest but on the surrounding branches.
They move around by hopping, skipping and even climbing branches using their wings and beak. Owlets begin to attempt their first short flights at five weeks of age. Owlets continue to be fed by both adults until they are six to eight weeks old, when the female leaves them. This is followed by the male, who stops feeding the owls after ten to eleven weeks. Newly fledged owls reach reproductive maturity after a year and can then repeat the process with their own young.
Adult long-eared owls have been recorded as prey for several birds of prey, including the golden eagle (Aquila chrysaetos), great horned owl (Bubo virginianus), red-shouldered hawk (Buteo lineatus), common buzzard (Buteo buteo), barred owl (Strix varia), red-tailed hawk (Buteo jamaicensis), and peregrine falcon (Falco peregrinus). Nestlings are vulnerable to many predators, including birds of prey such as those mentioned above, crows, magpies, porcupines, raccoons, and snakes.
To avoid being attacked, owls perch against tree trunks. Their distinctive morphological features, such as ear tufts and elongated body, along with cryptic plumage, allow them to camouflage themselves against the tree, making them difficult to see.
Adult short-eared owls defend their young eggs by bombing predators while giving alarm calls. In some cases, they may feign injury to attract the threat’s attention away from vulnerable nestlings or eggs. When owls nest in loose colonies, many owls from other nests may defend the single nest under threat.
Unfortunately, the dangers owls cannot protect themselves from are those imposed by humans. Motor vehicle collisions and shootings kill many owls.
The short-eared owl is relatively common throughout its range, but its population numbers and trends are difficult to determine due to its nomadic movements and secretive lifestyle. The global population size is generally thought to be declining due to habitat loss.
However, the number of individuals has been observed to vary annually, making it difficult to establish a precise population trend. However, the global population is estimated to be between 2,200,000 and 3,700,000 individuals, making it a species of little conservation concern.
Owls require grassland or shrubland and woodland, ideally next to each other, so the species is vulnerable to losing these habitats. The species may benefit from human disturbances, such as forest fragmentation, as this opens up spaces for the owls to hunt next to the wooded areas in which they nest.
The short-eared owl is a widespread species that feeds primarily on small mammals. It relies on adjacent wooded and open areas to successfully breed and hunt.
The global population is not seriously threatened. However, management practices are needed to conserve areas and prevent further decline in the population size of the unique long-eared owl.
