INDONESIA - SUMATRAN OWL - 26 SEPTEMBER 2015

Bubo sumatranus

Introduction:

The Barred or Malay Eagle Owl is a large, striking owl with barred underparts and very long, outward slanting ear-tufts. The species name "sumatranus" is the Latinised form of Sumatra, where the first specimen described was located.

Description: The facial disc is dirty greyish-white with no distinct rim. Eyebrows are whitish and not very conspicuous. The eyes are dark brown or dark hazel, with yellow to pale grey rimmed eyelids. Juveniles have dark bluish irises. The bill and cere are pale yellow, the cere sometimes having a greenish tinge. Ear-tufts are very long, tousled, outward-slanting and are blackish-brown with the inner webs delicately barred white and brown. Upperparts are dark brown, vermiculated and mottled with many paler zigzag bars. The tail is dark brown with about 6 tawny-whitish bars and a white tip. The upper breast is densely marked with thin whitish-buff and relatively broad earth-brown bars, varying individually in intensity, forming a dark breast-band. The rest of the underparts are buffish-white with scattered, irregular, often arrow-shaped dark brown spots. Tarsi are feathered to the base of the toes, sometimes further. Toes are pale yellowish-grey with dark horn claws. Size: Length 40-46cm. Wing length 323-417mm. Weight 620g (1 individual). Females are slightly larger and heavier than males.

 

Habits:

The Barred Eagle Owl is a nocturnal or crepuscular bird. It roosts by day singly or in pairs, hidden in a lofty tree with dense foliage, often near the trunk. Voice: A deep hoot, Hoo or Hoo-hoo slightly dropping in pitch towards the end of the hoot with an interval of about 2 seconds between the notes of the double hoot. They also produce a 'cackling' of various syllables, shrieks and strangulated noises.

Food:

Feeds on large insects, birds and small mammals and reptiles.

Breeding:

This owl probably pairs for life, and pairs are very loyal to nest sites, returning year after year. Nests are in large tree holes, or commonly on the top of large Bird's Nest ferns. The female lays only one white oval egg (53.8-57.7mm x 42.8-44.9mm). In Java, eggs have been found in February and April, and nests with young in May and June. In Sumatra, nestlings and fledged young have been observed from March to May. In Borneo, young have been observed in February and March.

 

Habitat:

 

Evergreen forest with ponds and streams, gardens with large, densely foliaged trees, groves in cultivated country, sometimes not far from habitation. Ranges from sea level to 1000m elevation, rarely higher to about 1600m.