Species: Long-eared Owl
Asio otus
Description:
The Long-eared Owl, the
slimmest of all North American Owls, is more strictly nocturnal than
all other N. American owls except for the Elf and Saw-whet. 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 N.
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:
General:
This is a medium sized owl, fairly long-winged and slender with
conspicuous ear tufts. Length: 33-41 cm, weight:
260 g.
Adult Male:
Long, close-set ear tufts are prominent on perched birds but barely
discernible in flight. Yellow to golden eyes are surrounded by
elongated black patches. White eyebrows and a white patch at
the base of the black bill contrast with the buff to rusty facial
disk. 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:
Females are distinctly darker overall than males, with richer rust
colouring on the face and under parts, especially the thighs.
Similar Species:
Might be confused with the Great horned owl but is smaller and the
breast is streaked up and down, not crossed-barred as in the Great
horned; also it lacks the white throat and its long, dark ear tufts,
when raised are much closer together than those on other “eared
owls”.
Behavior:
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.
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.
|
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. The graph reflects capture
of one individual caught in September of 2010. Capture rates
are standardized as birds captured per 100 net hours from
2010 - 2012.
|
 |
|