Owls evoke more contrasting reactions from us than any other kind of birds beautiful, graceful, sinister, benign, wise, dumb, cute, scary, wealth, death. These reactions, especially the negative ones, probably arose over human history for many reasons, including their nocturnal nature, their front-facing eyes (a reflection of our own) and their “ominous” calls.

Owls are carnivores that have convergently evolved with diurnal birds of prey in having pointed beaks and sharp talons. They have also adapted wonderfully to a nocturnal lifestyle to occupy a different ecological niche and avoid competition.

Most of them are cryptically coloured, helping them stay hidden in plain sight during the day. Their forward-facing eyes give them better depth perception, enabling them to hunt with precision under the light of the moon and stars. Their ears are asymmetrically placed on either side of their head to help them understand the direction of sound coming from their prey. In most species, the wing feathers are specially adapted to help them fly silently. It not only helps them sneak upon their unsuspecting prey, but also ensures that they can hear the slightest movement of their prey without the disturbance of their wing beat. And, they can see what’s happening behind their back with the incredible ability to rotate their head up to 270 degrees!

Their hunting strategies are almost as varied as hawks (Accipitridae). The only niche they probably haven’t filled is that of scavengers (as in vultures). Brown Fish Owls and Spot-bellied Eagle-owls have been recorded scavenging on larger kills, but this is very rare. This is probably because they are outcompeted (and also threatened) by mammals at night.

Karnataka has 15 species of owls from the huge Spot-bellied Eagle-owl to the tiny scops owls and owlets in two families and ten genera. This diversity of species (around 40% of the 37 species recorded in India) is due to the variety of habitats across the state.

Many species of owls have projections on top of their heads that resemble external ears. These are, in fact, just skin projections covered in long feathers that have no function in the bird’s hearing. In some languages, there are different names for owls with and without ear tufts. In French, owls with ear tufts are called “hibou” and owls without ear tufts are called “chouette”. In Japanese, the corresponding names are “mimizuku” and “fukurou”. While the function of these ear tufts is not fully understood, there are various hypotheses about the actual function of these ear tufts:

  • Identification at night (especially during courting) – Since the same area might be occupied by both eared and non-eared species, the ear tufts help owls identify birds of their own kind at night due to the different silhouette.
  • Deterrent to mammalian predators – The ear tufts, along with the large forward-facing eyes, make them look more formidable to mammalian predators.
  • Camouflage while roosting – They break the shape of the owl and can conceal a roosting owl by looking like a twig or a broken branch.
  • Communication – Since the ear tufts can be controlled (raised upright or lowered completely), it is also hypothesised that they may be used to signal danger or safety between mates.

 

This first part covers the “eared owls” in the family Strigidae. The Sri Lanka Bay Owl (family Tytonidae) has projections that look like ear tufts too and will be covered in the second part of this article.

 

Family – Strigidae – Typical or True Owls

Pallid Scops Owl (Otus brucei)

This is a rare winter migrant that is sparsely recorded mostly in North-west India. The typical habitat of this bird is open areas that have a few trees. It is mainly nocturnal in activity. In the day, it is seen inside thick vegetation or camouflaged amidst the branches of big trees. It is grey in colouration, with thin streaks running across the underparts. Like the other scops owls, it has a pair of ear tufts atop its head.

The first record in South India (and Karnataka) was from Belagavi in 1995. It is possibly overlooked due to its small size and secretive nature and can be confused with the Oriental Scops Owl.

Pallid Scops Owl (Otus brucei)

Indian Scops Owl (Otus bakkamoena)

This is a resident scops owl that is more often heard than seen. A nocturnal bird, it spends the day within thick vegetation or inside tree hollows. It is distinguished from the other scops owls of Karnataka by its slightly stockier appearance and dark brown eyes (yellow eyes in the others).

Indian Scops Owl (Otus bakkamoena)

Oriental Scops Owl (Otus sunia)

This small owl has distinctive ear tufts like all scops owls. Two colour morphs grey and rufous are known. Its trisyllabic phrases of resonant, throaty notes  kroik ku kjooh can be heard across our forests at night.

Oriental Scops Owl (Otus sunia)

Indian Eagle-owl (Bubo bengalensis)

Once considered as a subspecies of the Eurasian Eagle-owl (Bubo bubo), this large horned owl calls the hilly and rocky scrub forests its home (hence the alternate name Rock Eagle Owl). It is unmistakable with its prominent ear tufts and huge yellow eyes. Its unmarked facial disc has a very clear black border. Usually found in pairs, the Indian Eagle-owl feeds mainly on small birds and rodents.

Unfortunately, the distinctive face with ear tufts and its haunting call make this the subject of superstitious beliefs and occult practices.

Indian Eagle-owl (Bubo bengalensis)

Spot-bellied Eagle-owl (Bubo nipalensis)

The largest species of owl in Karnataka inhabits the forests, giving it its alternate name Forest Eagle Owl. The call is a haunting deep booming hoot that echoes through the forests at night. With a formidable appearance, this owl is easily identified by its large size, slanted ear tufts, dark eyes, dark wings and upperparts and chevron-shaped marking on its white underparts. It is a rare sight in the forests as it is nocturnal. It is sometimes seen late in the evening on a cloudy day.

It is a powerful owl and is known to take prey such as peafowl, junglefowl, civets, chevrotains and even young muntjacs.

Spot-bellied Eagle-owl (Bubo nipalensis)

Brown Fish Owl (Ketupa zeylonensis / Bubo zeylonensis)

This is the most widespread and common species among the four species of fish owls (three of which are found in India). They are stocky in appearance, with prominent flat ear tufts. Found in forests wooded areas near water, it is often seen roosting on branches of old trees on the banks of water bodies.  

The bird is adapted for fishing, with a rough texture on the bottom of their toes that helps it grasp slippery fish.

Brown Fish Owl (Ketupa zeylonensis)

Short-eared Owl (Asio flammeus)

One of the most widespread bird species in the world, this medium-sized owl is recorded in five continents (barring Australia and Antarctica). It is a rare winter migrant to the grasslands across the state. Being a migratory species, its wingspan is proportionally larger than similar-sized owls.

The tiny ear-tufts, sometime hidden, on top of its head give the bird its common name. It is usually nocturnal, though crepuscular and diurnal hunting has also been recorded. During the day, these owls usually roost inside grass tussocks or thick vegetation, often in small groups.

Short-eared Owl (Asio flammeus)

 

References:

1. Praveen, J, Subramanya, S., Raj, V. M., 2016. A checklist of the birds of Karnataka. Indian BIRDS 12 (4&5): 89–118.

2. Chandran, A., Rasmussen, P. C., Jahan, S., & Praveen J., 2016. The Pallid Scops Owl Otus brucei in south-western India, with notes on its identification. Indian BIRDS 12 (2&3): 56–63.

3. Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 58, 274. ISBN 978-1-4081-2501-4.

4. Richard Gimmett, Carol Inskipp, Tim Inskipp, 2011. Birds of the Indian Subcontinent. Second Edition; Oxford University Presss

5. Sparks, J.; Soper, T. (1970). Owls: their natural and unnatural history. New York: Taplinger.