Sunda scops owl
(Otus lempiji)
(Otus lempiji)
Scops owls are typical owls in family Strigidae, most of them belonging to the genus Otus and are restricted to the Old World.
Otus is the largest genus of owls in terms of number of species, with approximately 45 living species known to date.
Scops owls are colored in various brownish hues, sometimes with a lighter underside and/or face, which helps to camouflage them against the bark of trees.
Some are polymirphic, occurring in a greyish- and a reddish-brown morph. They are small and agile, with both sexes being compact in size and shape.
The Sunda scops owl (Otus lempiji) is a small brown owl that is speckled with black on the upper parts and streaked with black on the lower parts. It has a light collar and dark eyes. This taxon is considered a subspecies of Otus bakkamoena by some authors.
It grows from 20 to 25 cm and can weigh 100 to 170 grams. It is mostly found in forests, mangrove and gardens but is occasionally attracted to buildings. It mainly consumes insects but will also eat rodents, lizards, and small birds. It is common throughout its range where there is suitable habitat.
The Sunda scops owl lines its nest with plant fibre. It will lay up to three eggs in a tree hollow from January to April. Its call is a whooping sound every ten to fifteen seconds.
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Otus
Species: O. lempiji
Binomial name Otus lempiji
(Horsfield, 1821)
Otus is the largest genus of owls in terms of number of species, with approximately 45 living species known to date.
Scops owls are colored in various brownish hues, sometimes with a lighter underside and/or face, which helps to camouflage them against the bark of trees.
Some are polymirphic, occurring in a greyish- and a reddish-brown morph. They are small and agile, with both sexes being compact in size and shape.
The Sunda scops owl (Otus lempiji) is a small brown owl that is speckled with black on the upper parts and streaked with black on the lower parts. It has a light collar and dark eyes. This taxon is considered a subspecies of Otus bakkamoena by some authors.
It grows from 20 to 25 cm and can weigh 100 to 170 grams. It is mostly found in forests, mangrove and gardens but is occasionally attracted to buildings. It mainly consumes insects but will also eat rodents, lizards, and small birds. It is common throughout its range where there is suitable habitat.
The Sunda scops owl lines its nest with plant fibre. It will lay up to three eggs in a tree hollow from January to April. Its call is a whooping sound every ten to fifteen seconds.
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Otus
Species: O. lempiji
Binomial name Otus lempiji
(Horsfield, 1821)
Buffy fish owl
(Ketupa ketupu)
(Ketupa ketupu)
The buffy fish owl (Ketupa ketupu), also known as the Malay fish owl, is a fish owl in the family Strigidae. It is native to Southeast Asia and lives foremost in tropical forests and wetlands. Due to its wide distribution and assumed stable population, it is listed as Least Concern on the IUCN Red List since 2004.
The buffy fish owl is buff brown with darker tawny brown feathers on the back. Its face is paler and it has light brown eyebrows. With an adult size of 40 to 48 cm (16 to 19 in) and a weight of 1,028 to 2,100 g (2.3 to 4.6 lb), it is the smallest fish owl species.
Like all fish owls, the buffy fish owl has prominent ear tufts on the sides of the head. Its wing feathers and tail are broadly barred yellowish and dark brown. The wings are distinctly rounded in shape. The underparts are a yellowish brown, rich buff or fulvous with broad blackish shaft stripes. Its long legs are not feathered.
The fish owls have large, powerful, and curved talons and a longitudinal sharp keel underneath the middle claw with all having sharp cutting edges that are very much like those of eagle owls. Unlike fish-eating diurnal raptors, they do not submerge any part of their body while hunting, preferring only to put their feet into the water, although fish owls wade into the shallows. The feathers of fish owls are not soft to the touch and lack the comb and hair-like fringes to the primaries, which allow other owls to fly silently in order to ambush their prey. Due to the lack of these feather-specializations, fish owl wing beats make sounds. The lack of a deep facial disc in fish owls is another indication of the unimportance of sound relative to vision in these owls, as facial disc depth (as well as inner ear size) are directly related to how important sound is to an owl's hunting behavior. Also different from most any other kind of owl, the bill is placed on the face between the eyes rather than below it, which is said to impart this fish owl with a "remarkably morose and sinister expression".
The buffy fish owl is rather noisy before breeding, and pairs may engage in bouts of duetting for several minutes at a time. During the daytime, it shelters often singly in densely foliaged trees.
The buffy fish owl feeds foremost on fish, crabs, frogs, small reptiles and birds. It also forages on carrion.
Stomach content found in Javan buffy fish owls included insects, winged ants and winged termites, goldfish (Carassius auratus), gold-ringed cat snake (Boiga dendrophila), immature false gharials (Tomistoma schlegelii), red junglefowl (Gallus gallus), black rat (Rattus rattus), and fruit bats.
It has been recorded consuming remains of a crocodile and a Sunda stink badger (Mydaus javanensis). The buffy fish owl does not produce firm pellets as do most owls. Instead, bones, frog and insect remains are ejected in pieces and fall to the ground below the roost. Prey remains have only been found within the nest, never around or below the nest as is commonly recorded in other owls. The buffy fish owl hunts mainly from the bank, swooping down much in the manner of a fish eagle but never getting its feathers wet. It also walks into shallow streams and brooks, additionally snatching food in such locations.
Eggs of buffy fish owls have mainly been found in February through April in western Java, less commonly into May, and in the Malay Peninsula also in September through January. The buffy fish owl frequently nests on top of a large fern (Asplenium nidus), but nests have also been recorded in the fork of a tall bough covered in ferns and moss, on orchid beds and in tree holes. More rarely, rocky sites have been used as nesting sites, even behind waterfalls. The nest is usually merely a scrape into the surface of a fern with no structure or lining, as owls do not build nests. Abandoned bird nests built by other species have been used, including those of brahminy kite (Haliastur indus). Only one egg per breeding season has ever been recorded in a buffy fish owl nest, giving them the smallest clutch size of any owl.
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Ketupa
Species: K. ketupu
Binomial name Ketupa ketupu
(Horsfield, 1821)
The buffy fish owl is buff brown with darker tawny brown feathers on the back. Its face is paler and it has light brown eyebrows. With an adult size of 40 to 48 cm (16 to 19 in) and a weight of 1,028 to 2,100 g (2.3 to 4.6 lb), it is the smallest fish owl species.
Like all fish owls, the buffy fish owl has prominent ear tufts on the sides of the head. Its wing feathers and tail are broadly barred yellowish and dark brown. The wings are distinctly rounded in shape. The underparts are a yellowish brown, rich buff or fulvous with broad blackish shaft stripes. Its long legs are not feathered.
The fish owls have large, powerful, and curved talons and a longitudinal sharp keel underneath the middle claw with all having sharp cutting edges that are very much like those of eagle owls. Unlike fish-eating diurnal raptors, they do not submerge any part of their body while hunting, preferring only to put their feet into the water, although fish owls wade into the shallows. The feathers of fish owls are not soft to the touch and lack the comb and hair-like fringes to the primaries, which allow other owls to fly silently in order to ambush their prey. Due to the lack of these feather-specializations, fish owl wing beats make sounds. The lack of a deep facial disc in fish owls is another indication of the unimportance of sound relative to vision in these owls, as facial disc depth (as well as inner ear size) are directly related to how important sound is to an owl's hunting behavior. Also different from most any other kind of owl, the bill is placed on the face between the eyes rather than below it, which is said to impart this fish owl with a "remarkably morose and sinister expression".
The buffy fish owl is rather noisy before breeding, and pairs may engage in bouts of duetting for several minutes at a time. During the daytime, it shelters often singly in densely foliaged trees.
The buffy fish owl feeds foremost on fish, crabs, frogs, small reptiles and birds. It also forages on carrion.
Stomach content found in Javan buffy fish owls included insects, winged ants and winged termites, goldfish (Carassius auratus), gold-ringed cat snake (Boiga dendrophila), immature false gharials (Tomistoma schlegelii), red junglefowl (Gallus gallus), black rat (Rattus rattus), and fruit bats.
It has been recorded consuming remains of a crocodile and a Sunda stink badger (Mydaus javanensis). The buffy fish owl does not produce firm pellets as do most owls. Instead, bones, frog and insect remains are ejected in pieces and fall to the ground below the roost. Prey remains have only been found within the nest, never around or below the nest as is commonly recorded in other owls. The buffy fish owl hunts mainly from the bank, swooping down much in the manner of a fish eagle but never getting its feathers wet. It also walks into shallow streams and brooks, additionally snatching food in such locations.
Eggs of buffy fish owls have mainly been found in February through April in western Java, less commonly into May, and in the Malay Peninsula also in September through January. The buffy fish owl frequently nests on top of a large fern (Asplenium nidus), but nests have also been recorded in the fork of a tall bough covered in ferns and moss, on orchid beds and in tree holes. More rarely, rocky sites have been used as nesting sites, even behind waterfalls. The nest is usually merely a scrape into the surface of a fern with no structure or lining, as owls do not build nests. Abandoned bird nests built by other species have been used, including those of brahminy kite (Haliastur indus). Only one egg per breeding season has ever been recorded in a buffy fish owl nest, giving them the smallest clutch size of any owl.
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Ketupa
Species: K. ketupu
Binomial name Ketupa ketupu
(Horsfield, 1821)
Spotted Wood Owl
Shot at Cashew terrace 2019
The spotted wood owl is an owl of the earless owl genus, Strix. Its range is strangely disjunct; it occurs in many regions surrounding Borneo, but not on that island itself.
The three subspecies are:
Strix seloputo seloputo - South Myanmar and central Thailand to Singapore. Also Jambi (Sumatra) and Java.
Strix seloputo baweana - Endemic to Bawean Island off North Java
Strix seloputo wiepkini - Calamian Islands and Palawan (Philippines)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Strix
Species: S. seloputo
Binomial name Strix seloputo
The three subspecies are:
Strix seloputo seloputo - South Myanmar and central Thailand to Singapore. Also Jambi (Sumatra) and Java.
Strix seloputo baweana - Endemic to Bawean Island off North Java
Strix seloputo wiepkini - Calamian Islands and Palawan (Philippines)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Strix
Species: S. seloputo
Binomial name Strix seloputo
Brown Hawk-Owl
Shot at MacRitchite Reservoir 2019
The brown hawk-owl (Ninox scutulata), also known as the brown boobook, is an owl which is a resident breeder in south Asia from India, Sri Lanka, Bangladesh and Nepal east to western Indonesia and south China.
The brown hawk-owl is a resident breeder in most of tropical south Asia from the Middle East to south China. Its habitat is well-wooded country and forest.
It lays three to five eggs in a tree hole.
The brown hawk-owl is a medium-sized (32 cm) owl with a hawk-like shape due to its long tail and lack of a distinct facial disk. The upperparts are dark brown, with a barred tail. The underparts are whitish with reddish-brown streaking, although the subspecies found in the Andaman Islands has dark brown underparts. The tail is barred. The eyes are large and yellow. Sexes are similar.
This species is very nocturnal but it can often be located by the small birds that mob it while it is roosting in a tree. It feeds mainly on large insects, frogs, lizards, small birds, and mice.
The call is a repeated low soft, musical oo-uk ...ooo-uk... which may be heard at dusk and dawn. This owl is quite common in towns and cities like Colombo, Sri Lanka as well as suburban areas close to buildings.
There is only one record of the brown hawk-owl in the western hemisphere, an individual photographed on St. Paul Island, Alaska, on August 27, 2007.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Ninox
Species: N. scutulata
Binomial name Ninox scutulata
The brown hawk-owl is a resident breeder in most of tropical south Asia from the Middle East to south China. Its habitat is well-wooded country and forest.
It lays three to five eggs in a tree hole.
The brown hawk-owl is a medium-sized (32 cm) owl with a hawk-like shape due to its long tail and lack of a distinct facial disk. The upperparts are dark brown, with a barred tail. The underparts are whitish with reddish-brown streaking, although the subspecies found in the Andaman Islands has dark brown underparts. The tail is barred. The eyes are large and yellow. Sexes are similar.
This species is very nocturnal but it can often be located by the small birds that mob it while it is roosting in a tree. It feeds mainly on large insects, frogs, lizards, small birds, and mice.
The call is a repeated low soft, musical oo-uk ...ooo-uk... which may be heard at dusk and dawn. This owl is quite common in towns and cities like Colombo, Sri Lanka as well as suburban areas close to buildings.
There is only one record of the brown hawk-owl in the western hemisphere, an individual photographed on St. Paul Island, Alaska, on August 27, 2007.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Ninox
Species: N. scutulata
Binomial name Ninox scutulata
Bubo sumatranus
Barred Eagle-Owl
Barred Eagle-Owl
Shot at Fuyong Interim Park along park connected to Singapore Quarry 2019
The barred eagle-owl (Bubo sumatranus), also called the Malay eagle-owl, is a species of eagle owl in the family Strigidae. It is a member of the large genus Bubo which is distributed on most of the world's continents.
This relatively little-known species is found from the southern Malay Peninsula down a string of several of the larger southeast Asian islands to as far as Borneo. It forms a superspecies with the physically similar but larger spot-bellied eagle-owl (Bubo nipalensis), although the two species appear to be allopatric in distribution.
Distribution and habitat
It is found in Brunei, Cocos (Keeling) Islands, 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.
The barred eagle-owl is a fairly large owl but relatively small eagle-owl, this species ranges 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 eart 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 occasions where this species has had 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-owl are pure white in their natal down. Whitish 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.
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 and a strongly defined brownish-cinnamon face disc. Also the wood owl has more extensive feathering on its feet, which can almost totally cover their feet but for the talons.
Also, the buffy fish owl (Bubo ketupu) is found in almost the same exact range, similarly replacing the more northern and western brown fish owl (Bubo zeylonensis) to the way the barred replaces the spot-bellied eagle-owl. Fish owls have no feathering on their tarsi, have different, more tawny overall colour and lack the white stripe on the head and ear tufts.
Another species that occurs in the range (northern part of the range) of the barred eagle-owl is the dusky eagle-owl (Bubo coromandus), but that species has a sandy, warm brown colour rather than stark, greyish brown, possesses vertical rather horizontal barring on the underside, bears minimal contrasting whitish barring to the plumage and face and the eyes are yellow rather than dark brown.
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 with this species.
The spot-bellied species is much larger and has bolder spotting below, otherwise it is almost identical. While linear dimensions suggest that spot-bellied eagle-owls in Malay Peninsula would be nearly twice the size of barred eagle-owls (of the relatively small nominate subspecies) found no more than 100 km (62 mi) to the south, the larger barred eagle-owl subspecies
(B. sumatranus strepitans) found on Java and Bali is roughly equal in body size to the small island race of spot-bellied eagle-owl (B. nipalensis blighti) found far to the west on Sri Lanka.
Voice
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 1.9 to 2 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.
This relatively little-known species is found from the southern Malay Peninsula down a string of several of the larger southeast Asian islands to as far as Borneo. It forms a superspecies with the physically similar but larger spot-bellied eagle-owl (Bubo nipalensis), although the two species appear to be allopatric in distribution.
Distribution and habitat
It is found in Brunei, Cocos (Keeling) Islands, 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.
The barred eagle-owl is a fairly large owl but relatively small eagle-owl, this species ranges 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 eart 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 occasions where this species has had 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-owl are pure white in their natal down. Whitish 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.
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 and a strongly defined brownish-cinnamon face disc. Also the wood owl has more extensive feathering on its feet, which can almost totally cover their feet but for the talons.
Also, the buffy fish owl (Bubo ketupu) is found in almost the same exact range, similarly replacing the more northern and western brown fish owl (Bubo zeylonensis) to the way the barred replaces the spot-bellied eagle-owl. Fish owls have no feathering on their tarsi, have different, more tawny overall colour and lack the white stripe on the head and ear tufts.
Another species that occurs in the range (northern part of the range) of the barred eagle-owl is the dusky eagle-owl (Bubo coromandus), but that species has a sandy, warm brown colour rather than stark, greyish brown, possesses vertical rather horizontal barring on the underside, bears minimal contrasting whitish barring to the plumage and face and the eyes are yellow rather than dark brown.
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 with this species.
The spot-bellied species is much larger and has bolder spotting below, otherwise it is almost identical. While linear dimensions suggest that spot-bellied eagle-owls in Malay Peninsula would be nearly twice the size of barred eagle-owls (of the relatively small nominate subspecies) found no more than 100 km (62 mi) to the south, the larger barred eagle-owl subspecies
(B. sumatranus strepitans) found on Java and Bali is roughly equal in body size to the small island race of spot-bellied eagle-owl (B. nipalensis blighti) found far to the west on Sri Lanka.
Voice
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 1.9 to 2 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.
Dietary ecology
What little is known of the dietary habits of the barred eagle-owl indicates it has a very broad, opportunistic diet. Much like other eagle-owls, the barred eagle-owl has large, powerful feet for its size with large, heavy, slightly curved talons, indicating a diverse diet that can extend to relatively large prey given the opportunity.
Known foods have included large insects (i.e. grasshoppers and beetles), birds, small mammals (especially rodents including many mice and rats), and reptiles, largely snakes.
In one instance, an eagle-owl preyed on a young crab-eating macaque (Macaca fascicularis), which even at a young age is likely to be as large or larger than the eagle-owl. When held in captivity, this species is not choosy and will consume fresh meat from fish, birds and mammals.
In one instance, when kept in an aviary with a changeable hawk-eagle (Nisaetus cirrhatus), the owl killed and consumed the hawk-eagle despite its similar body size, indicative of a ferocity and lack of discrimination in regards to prey species, once again similar to other eagle-owls.
What little is known of the dietary habits of the barred eagle-owl indicates it has a very broad, opportunistic diet. Much like other eagle-owls, the barred eagle-owl has large, powerful feet for its size with large, heavy, slightly curved talons, indicating a diverse diet that can extend to relatively large prey given the opportunity.
Known foods have included large insects (i.e. grasshoppers and beetles), birds, small mammals (especially rodents including many mice and rats), and reptiles, largely snakes.
In one instance, an eagle-owl preyed on a young crab-eating macaque (Macaca fascicularis), which even at a young age is likely to be as large or larger than the eagle-owl. When held in captivity, this species is not choosy and will consume fresh meat from fish, birds and mammals.
In one instance, when kept in an aviary with a changeable hawk-eagle (Nisaetus cirrhatus), the owl killed and consumed the hawk-eagle despite its similar body size, indicative of a ferocity and lack of discrimination in regards to prey species, once again similar to other eagle-owls.
Breeding
This species probably pairs for life. Barred eagle-owls seems to be very attached to a particular nesting site. If not disturbed, they will occupy the same territory for several years and, if one partner dies, the surviving mate will maintain the same territory with another owl parent. This species nests either in large tree cavities or, in Java and Sumatra, on top of the large fern Asplenium nidus.
The only other known nesting location has been at the base of an epiphyte large enough to form a sheltered hollow against a large branch. Only one egg is laid, the smallest clutch size of any owl, tied with the buffy fish owl and the spot-bellied eagle-owl, which have also only been recorded with a clutch of only one egg. The egg is white with an oval shape, measuring about 59.8 mm × 47.9 mm (2.35 in × 1.89 in).
In Java, eggs have been found from February to April and nests with young from May to June.
In Sumatra, nestlings or dependent young have been observed in March through May and in Borneo, young have been observed in February through March.
Population
This species is found at low densities with large territories, as can be expected for most large birds of prey, but it is not uncommon. It is less common than the buffy fish owl on Java and Sumatra.
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus:Bubo
Species: B. sumatranus
Binomial name Bubo sumatranus
(Raffles, 1822)
Conservation status: Least Concern (Population stable) Encyclopedia of Life
Higher classification: Horned owls and eagle-owls
This species probably pairs for life. Barred eagle-owls seems to be very attached to a particular nesting site. If not disturbed, they will occupy the same territory for several years and, if one partner dies, the surviving mate will maintain the same territory with another owl parent. This species nests either in large tree cavities or, in Java and Sumatra, on top of the large fern Asplenium nidus.
The only other known nesting location has been at the base of an epiphyte large enough to form a sheltered hollow against a large branch. Only one egg is laid, the smallest clutch size of any owl, tied with the buffy fish owl and the spot-bellied eagle-owl, which have also only been recorded with a clutch of only one egg. The egg is white with an oval shape, measuring about 59.8 mm × 47.9 mm (2.35 in × 1.89 in).
In Java, eggs have been found from February to April and nests with young from May to June.
In Sumatra, nestlings or dependent young have been observed in March through May and in Borneo, young have been observed in February through March.
Population
This species is found at low densities with large territories, as can be expected for most large birds of prey, but it is not uncommon. It is less common than the buffy fish owl on Java and Sumatra.
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus:Bubo
Species: B. sumatranus
Binomial name Bubo sumatranus
(Raffles, 1822)
Conservation status: Least Concern (Population stable) Encyclopedia of Life
Higher classification: Horned owls and eagle-owls