The koel is an amazing strategist. She refuses to build her own nest. Instead, she lays eggs surreptitiously in the nests of several host species, the choice of victim varying from location to location. She usually chooses crows but sometimes chooses other species like Common Mynas, Golden Orioles and Common Magpies…
This article is a paean of love to the koel (cuckoo). I have survived the disappearance of the vulture which was an elegant, spare, bird that looked like a Roman patrician. I have survived the disappearance of the sparrow, which was the friendliest sweetest bird ever and a part of all the homes I have lived in. I have survived the disappearance of bees which came as a gift to the few flowers I grew in winter and whose steady drone always made me drowsy. But I think that if the koel disappeared, I would just give up the will to live. I have not seen the koel in my garden. She is very-very shy and any attempt to seek her out would drive her away. But she wakes me up in the morning and her infrequent kuhu during the day keeps me alert. Hard at work on the computer or on the phone or meeting people, her call causes my heart to skip a beat and I ask everyone with the pride of a mother: did you hear that, did you hear that???
My house, which used to be a parking lot, has become Delhi’s only house-forest and it has all sorts of birds in it. During the monsoon, we rise to the dawn chorus and the evening is heralded by the crows cawing their way home. The koel is obviously here to find a nest for her eggs. The Asian Koel is the Eudynamys scolopacea . The first name comes from a nymph of the sea and Scolopacea means stripe-backed. The Indian name Koel comes from the Tamil kuyil. Three types of koels are found in this part of Asia. The scolopacea is found in Pakistan, India, Nepal, Sri Lanka, the Maldives and Laccadive Islands. Our koel is the smallest of all.
The upper part of the female is black to blackish brown. It has little spots on the back and white bars on the wing and tail. Some of its feathers are reddish or light brown with whiter spots on the ends of feathers. Its under parts are dirty white to pale buff, throat and fore neck is a paler streaked blackish-brown with narrow blackish-brown bars on lower belly, thighs and flanks. The male is entirely black with dark metallic blue gloss, appearing purplish at times. It looks like a crow with a very long tail. When in moult, some old feathers fade to reddish-brown. The nestlings are uniformly black at first but moult quickly to look like adult females, Young males are dull slate with buff tips on feathers of breast, belly and wing. The eye irises are bright red, bill dull yellowish-green, the inside of the mouth is red.
The koel is found in orchards and lightly wooded areas in parks and gardens in towns and villages. It is a shy bird and easily overlooked during the winter months when it remains silent and unobtrusive. It walks along tree branches. It is rarely found on the ground, and only briefly seen in the open, when furtively dashing from cover to cover. It can sometimes be seen sunning itself on top of a tree early in the morning. During the breeding season the koel becomes obvious. Its loud, melodious and penetrating call is usually the first to be heard at dawn, while it is still dark, late into the night. The koel eats the berries of the Neem tree (Azadirachta indica), Peepal or Sacred Fig (Ficus religiosa), Banyan (Ficus benghalensis), Camphor tree (Cinnamomum camphora), Ber or Indian Plum (Zizyphus mauritiana), Mulberry (Morus), nuts of the Fishtail Palm (Caryota urens), the poisonous fruit of the Yellow Oleander (Thevetia neriifolia) and nectar from Coral Tree (Erythrina indica), Guava (Psidium guajava), Brazilian cherry (Eugenia uniflora), Wild Caper (Capparis sepiaria), Tamarind (Tamarinda indica), Wild Jujube (Ziziphus oenoplia), Pepper (Piper nigrum), and nuts of Oil Palm (Elaeis guineensis), Alexandra Palm (Archontophoenix alexandrae) and the fruit of the Bakul (Mimusops elengi) tree.
It also eats caterpillars, snails, mantids, stick insects and other insects. The koel is an amazing strategist. She refuses to build her own nest. Instead, she lays eggs surreptitiously in the nests of several host species, the choice of victim varying from location to location. She usually chooses crows but sometimes chooses other species like Common Mynas, Golden Orioles and Common Magpies. Her eggs are very much like those of the crow, but slightly smaller. They come in varying degrees of green, from pale greenish-yellow to greyish-green, profusely speckled and blotched with reddish-brown. Bird intelligence shows: The koel varies the colour of her eggs to match that of the hosts’ eggs. Can a human mother manipulate the slightest thing in her unborn child? Not only does this show the magic in the koel but recent studies have shown that colonies of birds that find themselves the victims of koels do some magic as well.
Dr. Claire Spottiswood from the University of Cambridge describes a continual evolutionary arms race between the host birds and koels: “As the cuckoo has become more proficient at tricking its hosts, hosts have evolved more and more sophisticated ways to fight back. One strategy of combating the brood parasite is for the females of the host species to each lay eggs of different colours and patterns. So from nest to nest, the eggs of the host birds look different. This means the cuckoo parasite is far less able to lay a counterfeit egg that matches the host eggs.” To enable the Koel to lay an egg within a crow’s nest, the couple devise a clever plan: Firstly, the male Koel stations itself very close to the crow’s nest, calling loudly and boldly to advertise his presence. The male and female crows promptly chase the intruder. The female Koel, lurking nearby under dense cover, quietly waits until the crows are far enough away, and then slips in to lay her egg into their nest.
The female usually lays just after the host has laid her first egg. The koel’s breeding season usually corresponds with that of its usual host and, during a single season, the female lays one egg each in several nests. Does the koel destroy her host’s eggs? Sometimes, if there is no space for hers. But many observers have seen young crows and koels in the nest together. The nestling period is 19 to 28 days and newly fledged young cuckoo are fed by its foster parents for another two to three weeks. Birdwatchers used to insist that the host birds were so stupid that they did not know the difference between their own and the koel’s young. Now, it has been discovered that the females, after laying their eggs, stay in the vicinity and if the hosts do not feed her young, they get attacked by the koel pair. When the young koel is ready to leave the nest, they take charge of the youngster directly. In India, the koel is part of Kamadeva’s armoury of seduction along with the scented breeze, the mango, the jasmine flowers and dolphin. Here is a lovely haiku type poem – A koel and the spring, I wait under a mango tree for a promise to be fulfilled.