Barred Eagle-Owl

Identificazione

The barred eagle-owl is a fairly large owl but relatively small eagle-owl, ranging from 40 to 48 cm (16 to 19 in) in length. There is almost no size sexual dimorphism in this species (although some females are marginally larger than the males) and adjacent island subspecies vary dramatically in size, both unusual attributes for eagle-owls. It is most distinctive due to its barred underparts, large but sideways-slanting ear tufts, a white bar running from the eyebrows through the front of the ear-tufts and much more heavily marked breast than belly. The face and lores are a dirty grayish-white colour. The eyes are usually a dark brown colour, but occasionally yellow eyes have been reported. The bill and cere are pale yellow, with an occasional greenish tinge to the cere. The upperparts are grey-brown, crossed and mottled with several zigzag bars of rufous-tawny colour, being broadest on the back. The upper-tail is dark brown with about six whitish or tawny bars. The tarsi are feathered to the toe joint. The juvenile barred eagle-owls are pure white in their natal down. The mesoptile stage in transition to adult plumage, is still a dirty white but is banded with brown on the wings and tail and the ear-tufts are much shorter than on mature birds.<p>A potential but unlikely confusion species is the brown wood owl (Strix leptogrammica), which is also barred below but as a Strix lacks this species distinctive ear-tufts. The brown wood owl also has much more rufous-brown color, a strongly defined brownish-cinnamon face disc and more extensive feathering on its feet, which can almost totally cover their feet but for the talons. Fish owls have no feathering on their tarsi, more tawny overall colour and lack the white stripe on the head and ear-tufts. Another species that occurs in the northern part of the range of the barred eagle-owl is the dusky eagle-owl (Ketupa coromanda), but that species has a sandy, warm brown colour, possesses vertical barring on the underside, bears minimal contrasting whitish barring to the plumage and face and the eyes are yellow. The spot-bellied eagle owl, with which the barred eagle-owl forms a superspecies, is much more superficially similar than any of the above owls but apparently does not overlap in the wild. The spot-bellied species is much larger and has bolder spotting below, otherwise it is almost identical.<p>The barred fish-owl territorial song or call is a deep hoot, hoo or hoo-hoo also sometimes transliterated as whooa-who, whooa-who. The hoots slightly drop in pitch towards the end. If it is a double-hoot, there is an interval of about two seconds between the hoots. Other vocalizations known for this species include a noisy cackle of various syllables, fearful shrikes and strangulate noises, normally uttered in the early evening. In Borneo, the barred eagle-owl's flight call is described as several hoots followed by a groan. In some local mythology on Java, the species' calls are considered as those of demons.

Tassonomia

Genere: Ketupa; famiglia: Strigidae; ordine: Strigiformes.

Nome scientifico

Ketupa sumatrana

Autorità

(Raffles, 1822)

Ordine

Strigiformi

Famiglia

Strigidae

Genere

Ketupa

Areale e habitat

It is found in Brunei, Indonesia, Malaysia, Myanmar, Singapore, and Thailand. Its natural habitat is subtropical or tropical moist lowland forests. It typically is a resident of evergreen forests with pools or streams, but also ranges into large gardens with tall, densely foliated trees, such as the Bogor Botanical Gardens found in West Java as well as wooded groves in cultivated country, both sometimes not far from human habitations. It usually ranges in elevation from sea-level to roughly 1,000 m (3,300 ft) but can range up to about 1,600 m (5,200 ft) or more at locations like Mount Gede in West Java and Mount Singgalang in West Sumatra.

Migrazione

Specie stanziale

Comportamento

Comportamento migratorio: Specie stanziale.

Conservazione

Tendenza della popolazione: in diminuzione.

Tendenza della popolazione

in diminuzione