Striped Owl - Asio clamator
Calls - Asio clamator
Introduction: The Striped Owl is a medium-sized owl with well developed ear-tufts. 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: The facial disc is brownish-white, with a distinct blackish rim. Eyebrows are short and whitish, and the eyes are brown to cinnamon. Lores are whitish, while the cere is greyish and the bill blackish. The ear-tufts are long and prominent, mostly blackish and somewhat tousled.
Upperparts are tawny-buff. The forehead, crown and nape are heavily streaked dusky. The mantle and back are mottled and streaked dark. The scapulars have whitish areas on the outer webs, forming an indistinct row across the shoulder. Flight feathers and tail are barred pale and dark brown. There is a blackish, plain patch at the wrist on the alulae which is very obvious in flight.
The throat is white, and underparts are pale tawny to buffish-white, prominently streaked dark brown or blackish. Tarsi and toes are feathered creamy. The claws are blackish.
Size: Length 30-38 cm. Wing length 228-294 mm. Tail length 127-165mm. Weight 320-556g. Females are heavier than males.
Habits: Mainly nocturnal, becomes active at sunset. By day the
Striped owl roosts in dense foliage of small trees or shrubs, sometimes on
the ground beneath 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 km.
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 more shrill song.
Both sexes have series of barking calls and fledged young give high-pitched
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 its own weight, such as pigeons, cavies and
white-eared opossums. Its hunting technique is 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 have also been 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. Ranges from sea-level up to approximately 1600m.
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
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.)
A. c. clamator,
A. c. forbesi,
A. c. midas,
A. c. oberi
Page compiled by Deane Lewis, José Carlos Motta-Junior & Adriana de Arruda Bueno. Page last updated 2013-08-07
OwlPages.com Owl Species ID: 280.010.000