Long-eared Owl

Asio otus

Introduction

The Long-eared Owl is the slimmest of all North American Owls. It is a secretive bird, and most birders have seen it only during the winter when it may gather in groups to roost in groves of pines or spruces. It is and Old and New World Owl. Within North America these owls breed as far north as the southern Yukon and Northwest Territories and as far south as northern Baja California and Nuevo Leon. They winter from southern Canada to Oaxaca and Veracruz in Mexico.

Identification

Adult Male (spring/summer)

Long, close-set ear tufts are prominent on perched birds but barely discernible in flight. Elongated black patches surround yellow to golden eyes. White “x” at center of face contrasts with rufous facial disc. The dark brown ear tufts are edged with light rust and white. The whitish to buff under parts are boldly streaked and barred dark brown. The dorsal plumage is dark brown with whitish to buff mottling. Buff wing patches and black wrist markings on the underside of the wings are visible in flight. The densely feathered legs and feet are buff to rust.

Adult Female (spring/summer)

Females are distinctly darker overall than males, with richer rust colouring on the face and under parts, especially the thighs.

Juvenile

Has loosely textured or down-like feathering; the feathers of the upperparts dusky with white tips, the facial pattern of definitive plumage lacking, and the iris brownish.

General Information

General:

This is a medium sized owl, fairly long-winged and slender with conspicuous ear tufts. Length: 33-41 cm. Wing: 91-92cm. Weight: 260 grams.

Behaviour:

Usually strictly nocturnal the Long-eared owl sometimes begins hunting before sunset, especially when feeding nestlings. They feed primarily on small mammals, concentrating on those that are locally abundant. Voles dominate their diet in much of North America. They mostly hunt on the wing, coursing back and forth close to the ground and seizing prey from the ground or from low vegetation. They sometimes hunt from perches, especially during windy weather.

Habitat:

Nest and roost in dense or brushy vegetation such as stands of coniferous or deciduous trees or willow thickets. They hunt in open habitats such as grasslands, meadows, open forests and deserts. They inhabit areas from near sea level to more than 2,000 m.

Information:

By day breeding males roost in trees near their nests, usually singly but occasionally with other males whose nests are nearby. During the nonbreeding season, long eared owls roost in dense thickets or tree groves beside open foraging areas, either alone or communally with up to a hundred other owls (usually 20 or less), often perched less than one meter apart. Long-eared owls sometimes nest in loose colonies with nests as close as 14 meters apart. They typically use stick nests made by other birds and lay two to ten white eggs.

Similar species:

Great Horned Owl, Short-eared Owl.

Conservation Status:

Long term trends are difficult to determine. There is evidence of declines in some parts of N. America. This species is listed as endangered, threatened or of special concern in a number of American States. Listed by IUCN as Least Concern.

Maps & Statistics

Capture Rates

Although consistently seen in the area, Long-eared owls are almost exclusively active at night and therefore not commonly captured at our station with only three individuals banded to date.

Ageing and Sexing (Band Size: 5, 6)

Molt Summary:

PF: HY partial (Jul-Oct); PB: AHY incomplete-complete (Jul-Oct); PA absent.
Molt occurs primarily on the summer grounds, completing during migration in some individuals.
Preformative molt includes all body feathers but no wing covs.
2nd PB: can be complete; when incomplete, up to 8 ss (among s1-s9; typically including s4, often s3 and s7, and sometimes others) and rarely p10 or p9-p10 can be retained, the pattern of retained feathers often being symmetrical.
Subsequent Adult PBs: can be complete or incomplete; when incomplete, up to 6 ss can be retained, usually not involving the same positions as are found on HY/SYs and less often symmetrical. The outermost 1-2 pp and pp covs rarely if ever retained. Replacement of the rects typically is complete during the adult PBs.

Juvenile

April - SEPTEMBER

Has loosely textured or down-like feathering; the feathers of the upperparts dusky with white tips, the facial pattern of definitive plumage lacking, and the iris brownish.

HY / SY

SEPTEMBER - August

This SY bird in May (see gallery below) is showing retained juvenal remiges, the primaries and secondaries uniform in wear and showing no contrasts.

Notice also the relatively large number of bars on the primaries and secondaries and the distance between adjacent bars on these feathers relatively small. Iris colour is yellow with brownish tinges.