My Science School

Many species of birds in India are dying out, says the first major report in our country on the state of bird populations. Things are particularly bad for the birds of prey, due to reasons like habitat destruction, hunting and pet trade. Several raptors like various species of eagles and harriers have come down in numbers, but vultures are the worst hit. Seven out of the nine vulture species found in India, have been decreasing in number since the early 1990s, mostly poisoned by an anti-inflammatory drug given to livestock.

India is certainly taking steps to conserve these birds, and our government has signed a memorandum of understanding (MoU) to save several species of migratory birds of prey in Africa and Eurasia. This is usually called the Raptor MoU.76 species are covered by this, of which 50 are in India including the endangered vulture. The government has also launched the Vulture Action Plan 2020-25, for saving the vultures. We are also a member of the SAVE (Saving Asia’s Vultures from Extinction) consortium.

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The tawny owl, or Strix aluco, is a medium-sized owl which belongs to the family Strigidae. This owl is found in woodlands across Eurasia and North Africa. It is sometimes called the brown owl because of its colouring, which is brown and sometimes gray. Its underparts are pale with dark streaks and it has a large, roundish head with dark eyes. Ear tufts are absent but it has exceptional hearing due to a symmetric ears. In fact, this owl’s hearing is 10 times better than a human’s! Often it uses only its ears while hunting at night.

This owl is non-migratory and fiercely territorial. So much so, that if a young owl fails to find a vacant territory within its home range, it will rather starve to death than move away! The tawny owl has the most iconic owl call or whistle. Its plaintive ‘Tu-whit tu-whoo’ has been immortalized in literature and films, as the quintessential owl cry.

It eats worms, insects, small mammals, reptiles, amphibians, fish and smaller birds. It usually creeps up on its prey with silent wings while the hapless victim is perched in a tree sleeping, or moving on the ground.

The tawny owl nests in tree holes, old magpie nests and cavities in buildings. The female typically lays around 2 to 3 glossy, white eggs which she incubates over a period of 30 days. Both parents look after the chicks for 2 to 3 months even after they have learnt how to fly. This species is very aggressive when defending their young. It will attack any intruder by striking them with its sharp talons. Because its flight is silent, it may not be detected until it is too late to avoid the danger. Dogs, cats and humans have been assaulted by them, sometimes without provocation.

The tawny owl is categorized under ‘Least Concern’ in the IUCN Red List, due to its stable population and wide range.

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The spotted owlet, or Athene brama, is an elegant little raptor that belongs to the family Strigidae. It is grayish-brown in colour with white spots all over its body. It has a roundish head, a pale facial disc, yellow eyes and prominent white eyebrows. Its upperparts are gray-brown - heavily spotted with white and its underparts are white - streaked with brown.

It is found in tropical Asia from mainland India to South-east Asia, where it prefers open to semi-open areas near farmland or human habitation. It is well adapted to living in and near cities due to the availability of rodents and insects like rats and cockroaches in these areas. It is known to use street lamps as hunting bases, since the light attracts insects which it can easily catch.

It is generally active at dusk and before dawn, but is sometimes seen during the day. At other times, it may be seen roosting in small groups or as a pair in tree holes or on branches. It also hunts bats, squirrels, toads, small snakes and scorpions. Its call is a loud

‘chirurr-chirurr-chirurr’ which ends in a ‘chirwak-chirwak’.

These owls are cavity nesters and females will lay 3 to 5 eggs at a time. Incubation lasts for 26 to 31 days and both parents share incubation duties. It is listed under ‘Least Concern’ in the IUCN Red List, since its population has remained stable over the years.

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The jungle owlet, or Glaucidium radiatum, is a small, rotund bird that belongs to the family Strigidae. It is found in India, Nepal, Bangladesh and Bhutan - where it inhabits scrub and deciduous forests in the Himalayas from Dalhousie in the west, to Bhutan in the east. It is also found south through peninsular India to north and east Sri Lanka.

This owlet is dark brown on its upper parts and finely barred all over in brown and white. For this reason it is also called the barred jungle owlet. It has a rounded head, brownish wings and a narrowly barred tail. It has a whitish patch on the chin, upper chest and in the centre of the abdomen. It has yellow eyes, a greenish beak and black claws. Its facial disc is indistinct and the false eyes that many owlets have at the back of their heads (to Scare off predators), is missing in this species.

This owl is most active at twilight and an hour or so before dawn. Such birds are called ‘crepuscular’. Although they will fly and hunt during the day (especially if the weather is cloudy), they are most likely to be seen roosting on a tree branch in the daytime. Their call is a loud musical trill, ‘praorr-praorr-praorr-praorr’.

This little raptor is an insect connoisseur! Its diet mainly consists of beetles, grasshoppers, locusts and cicadas. It also eats molluscs, lizards, mice and small birds. It is very tenacious and fearless when it comes to hunting and has strong talons to help it catch its prey.

This owlet makes its nests in natural tree hollows or abandoned woodpecker holes. Not much information exists about the incubation or breeding habits of this species. The female lays 3 to 4 roundish, white eggs. Most nest sites are 3 to 8 meters above the ground. This species is listed under ‘Least Concern’ in the IUCN Red List due to its large range.

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Ninox obscura, called Hume’s hawk-owl or Hume’s boo-book, is a medium-sized bird which belongs to the family Strigidae. It is endemic to the Andaman Islands in India, where it prefers moist lowland forests and mangroves. It also inhabits trees around cultivated fields, urban parks and rubber plantations. This owl has a chocolate brown plumage and a small whitish spot on its forehead between its eyes. Its head is round and its facial disk is ill-defined. Since ear tufts are absent in this species, it tends to look more hawk-like than others. Its underparts are paler than its upperparts and it has a long, banded tail. Its eyes and toes are yellow and its beak is dark and curved. Its legs and feet are covered with dark feathers.

This owl eats large insects, amphibians, lizards, small birds and small mammals. It is a highly nocturnal species and does most of its hunting at night. Its call is a repeated ‘wooooop’ or ‘ooo-uk’. A pair of these birds will form a lasting bond and take care of their young together. The female lays 3 to 5 white eggs in tree holes and is helped by the male to incubate them. These birds are non-migratory and disperse locally within the range after breeding.

This species is listed under the ‘Least Concern’ category in the IUCN Red List, since it is seen commonly within its range and its numbers are assumed to be stable. It faces threats from habitat destruction, human intrusion and trapping by pet traders.

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Taenioptynx brodiei, also called the collared owlet or collared pygmy owl, is the smallest owl found in Asia. It measures between 15 and 17 cm and weighs between 52 and 63 gms. This diminutive owl belongs to the family Strigidae and unlike most owls, is diurnal in nature.

It is gray-brown in colour with a barred back and sides. It has white eyebrows, lemon-yellow eyes and a white throat patch. Its chin, chest and belly are covered in white feathers and ear tufts are absent. It has two black spots on each side of the back of its head, making it seem like it is watching from behind! These false eyes can confuse potential predators and are present in many pygmy owl species. This feature is called the pygmy owl ‘occipital face’.

This bird has a very unique call – ‘wup-wuwu-wup’, which is made while turning its head in all directions. This creates a ventriloquial effect and it is difficult to locate the owl due to this. It hunts during the day and perches on a sparsely foliaged branch looking out for prey. It eats mice, insects, lizards, small birds and worms.

Its natural habitat is submontane and montane forests (forests formed on the slopes of mountains) and is found throughout Asia in countries like India, Bangladesh, Laos, Bhutan, Cambodia, China, Afghanistan and Malaysia. It is a resident bird across its habitat range and is a secondary cavity nester. This means it will occupy nests and tree hollows built by other bird species. It lays between 3 and 5 eggs and incubation occurs over 4 weeks. This species is listed under ‘Least Concern’ on the IUCN Red List and is mainly threatened by habitat loss.

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The brown wood owl, or Strix leptogrammica, is a medium-sized bird which belongs to the family Strigidae. It is a dark brown bird with white spots on its shoulders and brown striped underparts. Its facial disk is brown with prominent lighter-coloured circles around its dark brown eyes.

These birds are non-migratory and are found in India, Nepal, Bangladesh, Sri Lanka, Indonesia, Thailand, Cambodia, Taiwan and south China. Its natural habitat are dense forests at altitudes ranging from 750 to 2,500 metres. It is one of the most well known species of owl due to its wide range. Nocturnal in nature, it has several adaptations that help it to hunt at night. For starters, its eyes are larger than usual and are highly sensitive in the dark. It can also rotate its head 90 degrees vertically and 270degrees horizontally with the help of 14 vertebrae present in the neck, which helps it to spot prey. It has extremely good hearing capabilities and can locate its prey even if it is hidden under foliage.

This is due to asymmetrical ears that are located at different levels on its head which allows it to pinpoint the origin of sounds. Its wings are finely jagged which helps it to fly silently and pounce on its prey, taking it by surprise.

It eats bats, birds, reptiles, rats, frogs, mice, small birds and insects. These owls tear apart the prey before eating them and may be seen plucking out the feathers of birds before consuming them. This is because they are unable to digest feathers, hairs and bones.

They build their nests in tree cavities and caves. The female lays 1 to 2 eggs and the incubation period is about 30 days. They are listed as a species of ‘Least Concern’ on the IUCN Red List due to their large range.

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The buffy fish owl, or Ketupa ketupu, is a medium to fairly large owl which belongs to the family Strigidae. As its name would suggest, this fish owl is found near fish-bearing waters, often close to human habitation. It also inhabits tropical forests and freshwater wetlands such as mangroves as well as coastal areas covered with foliage. These owls are found in the eastern states of India, Bangladesh, Thailand, the Malay Peninsula, Sumatra, Java and Borneo.

It is a brown bird with tawny brown feathers on its back and a light-brown face with pale eye-brows. It has prominent ear tufts on the sides of its head and its wing and tail feathers are broadly barred with yellow and dark brown. Its long legs are not feathered and its beak is between its eyes rather than below it, giving it a somewhat glum expression! Its facial disc is undefined, indicating that this owl does not depend much on sound for its hunting (the deeper and more prominent the facial disc, the more acute the hearing of the owl).

Its diet consists mainly of fish, crabs, rats, mice, reptiles, frogs, toads and insects. It hunts from a perch, usually at the water’s edge or from a wooded bank, swooping down to catch prey just under the water’s surface. It will also wade in shallow streams looking for crabs, frogs and fish. It is persecuted by local fisherfolk because it will also hunt farmed pond fish.

It prefers to nest in the fork of a thick tree with adequate green cover and also in tree hollows and caves. It will also use the nests of other raptors when available. It usually lays one or two dull, white eggs and incubation lasts between 28 and 29 days. This bird species is listed under ‘Least Concern’ on the IUCN Red List.

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The Asian barred owlet, or glaucidium cuculoides, is a small-sized, rotund owl which belongs to the family Strigidae. It is a chocolate brown bird with a rounded head and absent ear tufts. It is extensively and evenly barred all over its body and hence its name – ‘barred owlet’. It has a yellow beak, chrome yellow feet and beautiful luminescent, yellow eyes that glow in the dark.

As its name suggests, the Asian barred owlet is found only in Asia - in Pakistan, Nepal, Bhutan, Myanmar, Bangladesh, China and Vietnam. In India it ranges across north and central and northeast parts of the country. It prefers forests of pine and oak at higher elevations and inhabits subtropical and tropical evergreen jungles at lower elevations. It is sometimes found in gardens and parks as well.

It eats beetles, grasshoppers, cicadas and other large insects as well as lizards, mice and small birds. It has been observed hunting quail by grabbing it mid-air in a hawk-like move. Unlike other typical owls, this bird is diurnal and is found perched on branches or tree stumps in broad sunshine or hunting during the day. It is a non-migratory resident bird that will sometimes kill other birds and take over their nests for breeding. The female is generally larger than the male and lays up to 4 white eggs, which she incubates over 4 weeks.

This bird is also known as the cuckoo owlet. Its call is a long series of mellow toots which is mostly heard at night. It is listed under ‘Least Concern’ in the IUCN Red List and is one of the few owl species whose population has actually increased over the years!

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The little owl, or Athene noctua, is a small bird which belongs to the family Strigidae. Also called the owl of Athena or owl of Minerva, it is found in central Europe, Africa, India, China, Mongolia and Russia. In India it is found in Himachal Pradesh, Uttarakhand, West Bengal, Sikkim and Arunachal Pradesh.

It has long legs, yellow eyes and its plumage is grayish-brown and streaked with white. It weighs about 180 gms and has a wingspan of 56 cm. It has a large, flattish head, a round body and short tail. Its facial disc is flattened above the eyes and this, together with its white eyebrows give it a no-nonsense, stern expression!

It is a nocturnal bird and prefers a range of habitats that includes farmland, woodland edges, steppes and semi-deserts. It eats insects, worms and small mammals. These owls like to perch on branches and swoop down on their prey. They hoard surplus food in tree holes and are good vocalists with a variety of calls. The calls of the males are much clearer and sharper than the females.

The nesting sites are usually cavities in trees as well as holes in the walls of buildings. They are also known to accept nesting boxes for laying eggs. These owls are very neat and like to clean the cavity before laying eggs! Sometimes the same nest is used over and over again. It usually lays a clutch of around 4 eggs during the breeding season. The female takes charge of incubating the eggs while the male hunts for food and feeds her during this time. The incubation lasts 22 to 28 days. The owlets are cared for by both parents for about 3 months till they can fend for themselves and leave their home territory.

This owl species is listed under ‘Least Concern’ by the IUCN due to its wide range and stable population.

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The Andaman hawk-owl, or Ninox affinis, is a medium to small-sized owl which belongs to the family Strigidae. It is endemic to the Andaman Islands of India. Also called the Andaman boo-book, this owl has a round head and no ear-tufts, a grayish facial disc, yellow eyes and a yellowish bill.

It feeds mainly on insects such as moths and beetles, catching them mid-flight. It prefers tropical and subtropical, moist lowland forests, lowland secondary forests and mangrove forests. They are found all over the Andaman Islands and are non-migratory, resident birds, and disperse locally after breeding. There is no information on the reproduction and breeding habits of this owl species.

The overall global population of this species is decreasing. Habitat destruction and the capture of adults and juveniles for trading as pets are the main threats endangering their survival. Earlier, this species was listed under ‘Near Threatened’, but in 2017 it was upgraded to ‘Least Concern’ status by the IUCN.

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The Indian scops owl, or Otus bakkamoena, is a small-sized owl which belongs to the family Strigidae. It is a resident species native to South Asia and ranges from India, Pakistan, Nepal and Iran. It is similar to the collared scops owl but can be distinguished by its call. Its call is a soft single note, ‘whuk’ while the collared scops owl has a longer ‘gook-gook’.

It has gray or brown upper parts which are faintly spotted. The underparts have fine, dark streaks and its legs are feathered grayish-brown or white up to the base of its toes. Its toes are brown or greenish-yellow with pale brown talons. It has small ear tufts and dark brown or orange-coloured eyes. Its colouring allows it to blend with the background and it can generally camouflage itself much better than other owls.

It prefers to hunt during the night and spends the day sleeping in hollow trees. Its camouflage makes it very difficult to spot. It feeds mainly on insects including beetles and grasshoppers and will occasionally eat lizards, mice and small birds. It prefers forests and groups of densely foliaged trees in gardens, mango orchards and fruit trees around villages and cultivations. It is found mainly in lowlands.

This owl lays about 3 or 4 eggs and its incubation period lasts 28 to 29 days. The owlets take about 21 to 25 days to become fledglings (or ready to fly). The Indian scops owl is not endangered and has a stable population. It is listed under ‘Least Concern’ in the IUCN Red List.

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The oriental scops owl, or Otus sunia, is a small owl which belongs to the family Strigidae. Weighing about 95 grams and with a wingspan of 52 cm, these tiny owls have three types of plumages-gray-brown, reddish-brown or rufous and the more uncommon golden plumage. They may be distinguished from the collared owls by a white scapular stripe and well marked underparts. This owl has striking yellow eyes, whitish eye-brows and ear tufts that may not always be visible. Females are slightly larger in size and its call is a liquid sounding ‘tuk tok torok’.

It is found in deciduous and mixed forests, semi-open woodland, open evergreen forests and savannas. It may be found also in parks, orchards, gardens and temples. It is a nocturnal bird and will roost in a tree hole or against a tree trunk during the day. If disturbed this owl will ‘freeze’ with half opened eyes. It is an agile hunter and takes its prey off a perch or in mid-air. Its diet comprises insects, spiders, small birds and lizards.

The nest is usually a hole in a tree or a wall and the female will lay from 3 to 6 eggs which she incubates over 24-25 days.

This owl is found in Pakistan, India, Nepal, Bangladesh, Sri Lanka, Japan, Siberia, Manchuria, Taiwan, China and the Malay Peninsula. It is also found in the Andaman and Nicobar Islands. Since it has a very wide range, it is not threatened as of now and it is listed as ‘Least Concern’ in the IUCN Red List. 

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The spot-bellied eagle-owl, or Bubo nipalensis, is an immense and intimidating owl which is considered part of a super-species of owl along with the barred eagle-owl. It is silver-gray or brown in colour with a large yellow beak, black eyes and feathered legs and feet. Its ear tufts or sideward-facing ‘horns’, are long and sweeping, giving it a formidable and unmistakable appearance. The overall plumage of this owl is dark brown on the head, upper wings and upper parts. The throat and the underparts are pale brown. The sides have black and white horizontal stripes.

It is a forest dwelling species, and is also known as the forest eagle-owl. It is found in the Indian subcontinent and in south-east Asia including Burma, central Laos and central Vietnam. In India it is found in the lower Himalayas in Kumaon and also in Tamil Nadu, Kerala, Goa, Karnataka, Maharashtra, Sikkim, Assam, Arunachal Pradesh, Nagaland, Meghalaya, Manipur, Tripura and Mizoram.

It is nocturnal by nature and will roost in dense foliage of large trees during the day. However it has been found that these owls will also hunt during the day when possible, especially in forests with minimal human disturbance. It is a bold and fearless hunter and will often hunt prey that is heavier than itself. Its primary prey are pheasants, jungle-fowl, peafowl and game-birds, but it will also hunt jackals, hares, civet cats, snakes, monitor lizards, monkeys and even small-sized deer!

This owl usually nests in large tree cavities. It will also make use of abandoned large stick-nests of eagles, vultures or kites and occasionally nests in sheltered rock crevices, fissures and caves.

This owl is a non-migratory, resident bird. The female lays 1 white egg at a time and carries out incubation alone. It is listed under ‘Least Concern’ in the IUCN Red List, but is threatened by locals and poachers due to its formidable appearance and eerie scream (It has a low, double hoot, ‘hoohoo’ and a mournful mewing scream that rises and falls in a blood-curdling ‘njaa-uuuw’).

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The collared scops owl, or Otus lettia, is the largest of the scops owl species and belongs to the family Strigidae. It was described for the first time by Brian Houghton Hudgson in 1836. It is found in northern India and Pakistan, Nepal, Bangladesh, south China and Taiwan, typically in evergreen forests, woodlands and deciduous forests.

It is a light gray bird with an off-white facial disc rimmed in black. Its upper parts are light beige mottled by black and dark brown markings. Its eyes are dark brown and it has long, spotted ear tufts and an off-green beak. It has rounded wings, feathered legs and gray-brown toes and claws. The bosom and belly are creamy brown. This owl is known as the king of camouflage as it blends into the nearby branches and is indistinguishable against any brown background.

It prefers to eat grasshoppers, birds, beetles and other insects and will occasionally consume lizards, rodents and frogs. It communicates by hooting and the length of the hoot depends on the nature of the call.

The female lays 3 to 5 eggs which are incubated by both parents over the period of a month. This species is spread across a large range and its population is steady. It is listed under ‘Least Concern’ by the IUCN.

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