Striped Owl - Asio clamator
Originally placed in genera Rhinoptynx and Pseudoscops
Calls - Asio clamator
The first published description
of the Striped Owl was made in 1807 by Louis Jean Pierre Vieillot. This owl was often included in the genus Rhinoptynx,
but is now considered Asio.
[For help with terms used in the description, see parts of an owl. For general characteristics common to most owl species, see owl physiology.]
Description: This medium-sized owl has ear tufts that are well
developed and projected to the sides or to the top (when disturbed) of the
head. Its large ears are complex and asymmetrical, and extraordinarily
sensitive. It has a strongly defined white blackish-rimmed facial disc, dark
brown eyes and almost blackish bill. Its upperparts are yellowish-brown to
tawny–ochre, striped with grimy brown. Below it is buff or white, with dark
brown stripes. It has short wings and a long tail, the flight feathers and
tail have alternated buff and grimy brown bands. Tarsi and toes are
feathered. It has powerful talons for their body size.
Size: Length 30-38 cm (12-15"). Wing 22.8-29.4 cm (9-11.5"). Weight 320-546 g (11.25-19.25 oz).
Habits: Mainly nocturnal, becomes active at sunset. By day the
Striped owls roost in dense foliage of small trees or shrubs, sometimes on
the ground beneath a vegetation cover or even in pine plantation. During the
non-breeding season several individuals may gather in flocks and roost
together by daytime. These owls fly with rather shallow and rapid wing beats
over open areas. Home range can be approximately 7 square kilometers (2.7
square miles).
Voice:
The usual vocalization is a long strident wheeyoo. The song of the male is
a series of well-spaced hoots while female gives a similar but shrill song.
Both sexes have series of barking calls and fledged young give high-pitched
screams, weehe.
Hunting & Food: Striped owls hunt mostly during crepuscular and
nocturnal hours. Small mammals and birds are its main prey. Mammalian prey
includes spiny rats, rice rats, cavies, bats and opossums. Bird prey
includes doves, grassquits, flycatchers, thrushes, house sparrows and
tinamous. Other foods include large insects and a few reptiles. Pellets are
irregularly shaped and mostly light grey. Its powerful talons including long
claws indicate large average prey. Indeed, the Striped Owl may take prey
approximately 0.7 times heavier than itself such as pigeons, cavies and
white-eared opossums. Its hunting technique was described as a low flight
over open landscape, with abrupt dives after prey. This owl also sits on a
perch and watches prey ready to catch them.
Breeding: Two to four eggs are laid in rudimentary nests found
on the ground in long grass and dense bushes. The female alone incubates for
approximately 33 days. Probably only one chick fledges successfully, though
two fledglings were also observed.
Mortality: Observations on mortality include road kills and
shootings. Natural enemies include probably larger owls and birds of prey.
Habitat: This owl prefers open or semi-open grassland and
savannas with scattered trees, small groves and bushes. It also occurs in
open marshland with bushes, pasture and agricultural land, as well as in
wooded suburban areas. Usually not present in dense forest, avoiding Amazon
basin. From sea level up to approximately 1,600m.
Distribution: Striped owls are distributed from southern
Mexico to Panama, and from northern South America to Uruguay and north
Argentina, east of the Andes. They apparently do not occur in the Amazonian
Basin and appear to be resident year-round.
Distribution of the Striped Owl Asio clamator
Status: Uncertain
Original Description: Vieillot, Louis Jean Pierre. 1808. Histoire naturelle des oiseaux de l'Amérique septentrionale, contenant un grand nombre d'espèces decrites ou figurées pour la première fois [Natural History of the birds of South America, containing a great number of species, described and illustrated for the first time]; 1807, p. 52, pl. 20. (1807-09 Paris. 2 vols.)
Subspecies:
A. c. clamator,
A. c. forbesi,
A. c. midas,
A. c. oberi
References:
Page Information:
Text and Range Map by José Carlos Motta-Junior & Adriana de Arruda Bueno
The text above was a combination of literature reviewing and personal field experiences by the authors. Page last updated 2012-07-30
OwlPages.com Owl Species ID: 280.010.000
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Juvenile calling parent for food
