The Asian Koel: All You Need to Know About THAT Noisy Bird

By Published On: January 22, 2023Last Updated: December 11, 2022

Woo-OOo! If you’ve lived in Asia, chances are you’ve been rudely awakened by the incessant cooing of this noisy bird. Both males and females have distinct calls (you’ve probably been annoyed by both); they look very different too! Learn all about the Asian Koel in this article.

The Asian koel (Eudynamys scolopaceus) is a bird that is part of the larger cuckoo family. They are found all over Asia but are especially common in Singapore, where they lay their eggs in the nest of house crows. Asian Koels exhibit sexual dimorphism, which means males and females of the species look (and, in this case, sound) very different.

All About the Asian Koel

Asian Koel Habitat and Behavior

Asian koels (Eudynamys scolopaceus) are part of the larger Cuculidae (cuckoo) family of birds. They are mainly found in India, China and Southeast Asia but have also been spotted in Australia and surrounding islands.

koel geographic distribution
Distribution of koels: Asian koel (in black), Australian koel (light blue), Australian Koel breeding/wintering range (dark blue)

Asian koels can grow as large as 46 cm (18 in) and live up to 14 years in captivity (they make great pets, apparently!)

Adolescents eat both insects and fruits but, interestingly, switch to an almost exclusive fruit (frugivorous) diet as they grow into adults. As such, they have evolved a large gape (ability to open their beaks wide) to swallow fruits hole, regurgitating large seeds and dispersing smaller ones in their poop.

Asian koels are mainly found perched on fruit trees and may even chase away other species that come too close to their food source.

Cuckoos: Brood Parasites

Being part of the cuckoo family, Asian koels (and all other koels) exhibit brood-parasitic behavior. This means koel females don’t build their own nests but rather lay their eggs in the nests of other birds hoping the host raises their young for them.

In Asian koels, their hosts are usually house crows (Corvus splendens) and the Javan myna (Acridotheres javanicus), common birds with the same geographical range.

Baby cuckoos often hatch before their hosts and immediately try to push the hosts’ unhatched eggs out of the nest (a prime example of genetically inherited behavior). To combat this, hosts build deeper nests that make it difficult for their parasites to perform this activity.

Species that are targeted by cuckoos must develop such strategies to combat brood parasitism. In a fascinating evolutionary arms race, their eggs have developed distinguishing features to help parents spot the odd egg out.

Interestingly, while most cuckoos keep up with this by changing their egg patterns to match their hosts, a study in 2021 showed that Asian koels had not evolved such egg mimicry behavior, with their eggs being significantly distinct from their host species.

asian koel eggs vs. myna house crow and long tailed shrike
Top Row: The eggs of common myna, house crow and long-tailed shrike (hosts). Bottom row: The parasitic Asian koel eggs found with the corresponding host eggs.

How Did the Asian Koel Get its Name?

Koels get their name from their calls, which sounds kind of like ‘ko-el’. It is an onomatopoeia, with many languages across Asia giving it different echoic names based on its calls:

ChineseZao juan
VietnameseTu hú

The morphology of its scientific name Eudynamys scolopaceus shares Greek and Latin origins, with eu and dunamis meaning fine and power, respectively, in Greek, and Scolopax being the Latin scientific name for the snipe/woodcock family of birds.

How to Identify Koel Birds: Male vs. Female

Where Can I Spot Them?

Most of the time, this bird finds you (in your sleep). But if you’re a fan of koel birds, or simply want to know your enemy, here’s a picture of a male:

male asian koel

And one of a female:

female asian koel

Though both males and females have beautiful crimson-red eyes, their plumage is distinctly different (sexual dimorphism): with males having pure black feathers and females exhibiting white mottles and stripes. Their beak color changes from black in young Asian koels to a lighter beige in adults.

Asian koels can be rather difficult to spot since koels are secretive birds that prefer perching behind dense foliage in the upper reaches of fruit trees. They obviously prefer to be heard rather than seen. This brings us to the next topic: identifying koels based on their calls.  

Identifying Koel Calls

Not to be confused with unsolicited calls from banks and insurance agents, koel calls can also be distinguished between males and females.

The clip below is of the characteristic male Asian koel bird call (source):

This one is apparently a male Asian koel’s response to disturbances (source):

Finally, the typical shrill undulations of females; this recording actually features two female koels communicating with each other:

About the Author

sean author
Sean Lim

Sean is a consultant for clients in the pharmaceutical industry and is an associate lecturer at La Trobe University, where unfortunate undergrads are subject to his ramblings on chemistry and pharmacology.

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