The call of the Asian Koel

on 19th September 2006

From mid-October 2005 right through to February 2006, I had been hearing the call of the Asian Koel (Eudynamys scolopacea) almost every morning at about 6.30 am or thereabout. Sometimes I would hear the call later in the morning and once in a while in the evening as well. I have had people complaining of being awaken by the call as early as 4.30 to 5.00 am but in my area the birds apparently wake up later.

These birds, there must be more than a pair, roost among matured trees growing in an abandoned area between two housing estates, seldom visited by people. As such I never saw them but always heard their calls.

Asian Koels are extremely shy birds. Years ago they were always heard and seldom seen. More recently they had been making their presence known especially when they visited my Alexandra palms (Archontophoenix alexandrae) to feed on the ripe fruits. But they were still shy, flying off once they noted my presence.

From mid-February 2006 the call dried up to an occasional kwaking. Then around the end of June the call was again heard, but not as regularly as previously.

During the first few days of July I had the opportunity to view them close-up. Four male koels flew in at around 5.30 pm and stayed for about an hour to an hour and a half. A bird would suddenly arrive and perch on a fruiting branch of my Alexandra palm accompanied by loud kwaking. Another would soon fly in to be followed by the remaining two. Sometimes they would fly to the Golden Penda (Xanthostemon chrysanthus) tree along the roadside.

A pair, perching on different branches but facing each other, would then indulge in duetting. The perching appeared precarious as the birds rocked forward and backward, as if trying to balance themselves. Their tails would flare out somewhat and sometimes they would touch beaks. During this time one or more may regurgitate seeds from earlier feeds. After some time they would simply perch quietly, not moving much and not appearing to communicate. Then suddenly they would all fly off.

A lone male koel was recently seen perching on a branch of the Golden Penda and wailing continuously. As it belted out a series of koel-koel-koel calls, its wings flap up while the tail feathers flare out. This went on for up to five minutes before the bird flew off.

Account and images by YC Wee.

If you like this post please tap on the Like button at the left bottom of page. Any views and opinions expressed in this article are solely those of the authors/contributors, and are not endorsed by the Lee Kong Chian Natural History Museum (LKCNHM, NUS) or its affiliated institutions. Readers are encouraged to use their discretion before making any decisions or judgements based on the information presented.

YC Wee

Dr Wee played a significant role as a green advocate in Singapore through his extensive involvement in various organizations and committees: as Secretary and Chairman for the Malayan Nature Society (Singapore Branch), and with the Nature Society (Singapore) as founding President (1978-1995). He has also served in the Nature Reserve Board (1987-1989), Nature Reserves Committee (1990-1996), National Council on the Environment/Singapore Environment Council (1992-1996), Work-Group on Nature Conservation (1992) and Inter-Varsity Council on the Environment (1995-1997). He is Patron of the Singapore Gardening Society and was appointed Honorary Museum Associate of the Lee Kong Chian Natural History Museum (LKCNHM) in 2012. In 2005, Dr Wee started the Bird Ecology Study Group. With more than 6,000 entries, the website has become a valuable resource consulted by students, birdwatchers and researchers locally and internationally. The views and opinions expressed in this article are his own, and do not represent those of LKCNHM, the National University of Singapore or its affiliated institutions.

Other posts by YC Wee

18 Responses

  1. In Sydney, the Koels appear to be able to keep their calls going all night at times. They will start calling late in the evening and continue until about 10pm or 11pm. Then they will start up again around 4am.

    We had one for years every summer in the big tree at the end of our street in Potts Point. Despite trying concertedly for every year, we never actually saw it, except once; it was chasing and being chased by a female up and down the street and calling loudly most of the time.

  2. It is interesting to document the call schedules from different parts of the world. Thanks Scot for the Aussie schedule. Many factors, I am sure, come into play.

  3. My housing estate have at least 1 pair of Koel. It’s weird but the Koels in my estate are not shy.

    I had heard their calls (F+M) sometimes at night too. Just 1/2 calls but not the continuous calling.

    The male was seen perching on the antenna of a semi-detached house calling on 2 ocassions. & it was hoping around on a 2-storey high tree when I passed by one morning. 1st time saw a Koel so near for me.

    A couple of times, the male Koel was seen flying between a roadside fruiting Alexandra palm and a nearby tree that has a female Koel hiding in it. Seems to me that the fruiting palm tree is the Koels’ canteen.

    There was once when 2 crows flew onto the palm tree & I was expecting the male Koel to attack them. Instead, he just stopped flying back to the nearby tree & stood his ground (branch). When the crows tried to move towards the red fruits, Koel then move to block the crows. They never fight for the 5 min I stoodstaring at the tree. Not too sure what happens later.

    On Mon, the female Koel was seen calling continuously while the male tried to move near it. Then both disppeared behind the thick leaves.

    On all ocassions, the Koels R seen when I was either on my way to work or back from work. Sorry, no time to wait around & observe more.

  4. Perhaps Asian Koels & other birds wake up later at more peaceful &/or darker residential districts (eg. landed properties) with minor roads traversed by few/no public buses, heavy vehicles & motorbikes ?

    Over here in a HDB estate at industrial Jurong, male Asian Koel calls typically start at around 4.15am. This coincides with the time when the traffic noise (50% quieter after 3am but nevertheless ongoing) starts becoming significantly noisy again. The first public bus that ferries staff-drivers to interchanges also arrives around this time.

    There was also a recent occasion when a male Asian Koel started calling at around 3am, while some neighbourhood cats were conducting a loud catfight.

    In addition, HDB estates also tend to be brightly-lit from 7pm to 7am, including the multi-storey carparks. Furthermore, there are always multiple residential units in every apartment block (12-40 storeys) that will have their lights blazing all night long until well after the sunrise.

    Occasionally, the male Asian Koel calls here at night too (between 9.30pm & 10:30pm) — like just now. However, the female (if present in the neighbourhood) never replies.

  5. Pat has raised a valid point. Disturbances often cause birds to call. In the days when I was maintaining several aviaries as well as songbirds in cages, a disturbance at night would often trigger a bout of calling. I have also observed this in wild mynahs and starlings which would continue chattering for quite a while after their roosts have been disturbed. And white-breasted waterhens are notorious for calling whenever anything approaches their nesting sites at night.

  6. I also notice that mynahs roosting communally in trees along the quieter back lanes may suddenly strike up a mass ruckus at night, when a lone loud vehicle passes by. Perhaps the culprit vehicle sounds like a threat (eg. gunshots or bird-culling shooters arriving).

    In contrast, I haven’t heard birds (including Asian Koels) suddenly call out because of thunder, although the unexpectedness & loudness of the latter sometimes startle me. But I reckon wild birds might call in chorus in response to relatively uncommon loud noises such as volcanic eruptions ?

    Also, do urban birds gradually get accustomed to the more “unusual” urban sounds over time & stop calling in reaction ? For instance, if the neighbourhood cats were to fight loudly at 3am daily, might the Asian Koel get used to it & go back to sleep ? Or might the Koel eventually bring forward its predawn call to 3am instead ?

    On the other hand, I wonder if birds’ alarm/ defensive calls in reaction to something approaching their nesting sites is favourable or detrimental to survival. I don’t suppose seasoned predators, pranksters or poachers would be deterred or scared off by bird sounds. If anything, the calls help narrow down the location of bird/ nest.

  7. I think that the vocalisations signal that the bird is awake, and perhaps ready to do battle. When pet shamas (Copsychus malabaricus) red-whiskered bulbuls (Pycnonotus jocus)and zebra doves (Geopelia striatia)are disturbed at night, they react with the same calls that they use during bird-singing competitions. These are territorial and threat calls. And my big cockatoos would go into full threat display (complete with ear-shattering screams) if disturbed at night. I don’t know enough about the calls of other types of birds to speculate what they mean.

  8. Do Asian Koels in S’pore observe a regular breeding season ? Or does the breeding season drift through the months, with the duration also varying year by year ?

    This article mentions “mid-October 2005 right through to February 2006”.

    For 2014, the male Asian Koels at industrial Jurong called multiple times everyday throughout the day between May/Jun & early Dec (ie. 6 continuous months of breeding).

    I wasn’t expecting to hear the birds for at least 3 months, but since mid Jan 2015, the males had started calling again everyday. However, there is no change to the earliest daily timing: around 4:15 am (ie. when the 1st public bus arrives to ferry drivers to the bus interchange).

    The interval between early Dec 2014 & mid Jan 2015 is just 5 weeks. Even if Asian Koels don’t ever get tired of mating, isn’t 5 weeks somewhat too short to raise a brood to maturity ?

    1. In 2003-2004 the koel laid her egg/s every 3 months in the House Crow’ nest lodged in the crown of my Seram palm. From that it would seem that koels breed throughout the year. Koels do not brood their chicks, crows do that for them.

      1. Based on how long the male Asian Koel calls lasted during the past years, I’d thought that the Koel’s breeding season lasted around 3 months. But at industrial Jurong, the breeding period didn’t run consecutively. There were periods of several months free from Koel calls. So Asian Koels breed the whole year round at quieter areas ?

        Oh yeah, I recalled about Koels laying eggs in crows’ nests only after sleepily submitting my comment (in response to again hearing the koels’ morning alarm-clock).

        Now I’m wondering if the Asian Koels might be mating more often because crows’ nests are being destroyed/ removed more frequently. Or at least the trees that make good roosting & nesting sites for crows are being hard-pruned or topped to ugly stumps quite regularly.

    2. There was a similar conversation on your question here:

      To add on what YC has mentioned, since I started to have an interest in birds 7 years ago, I have collected thousands of crow nest pictures in the Sin Ming area. The nests were found throughout the year – from Jan to Dec. They were built mostly in Sea Apple (Syzygium grande) planted in public housing estates. Occasionally they were found in Yellow Flame (Peltophorum pterocarpum), Mango (Mangifera spp), Jack Fruit (Artocarpus heterophyllus), Trumpet Tree (Tabebuia rosea), African Mahogany (Khaya grandifoliola), Brown Heart (Andira inermis), and Casuarina (Casuarina equisetifolia).

      As for the Koel call, some interpret if as a mating call. However, I have a different understanding. I think it is a contact call of the juvenile/immature to broadcast its location to the foster parents. As the young bird matures, its area of activities spread. At the same time the parents would pay less and less visits to feed the young. The call would enable the parents to locate it. There are lots of Koel in my area, but I hear at most 3 different (juvenile/immature) males. If the call is one for mating, then all the adult males should be actively calling. After all, reproduction is an instinct.

      1. How does one differentiate between the mating calls of adult Asian Koel males & the contact/ attention-seeking calls of juveniles/ sub-adult males ? I assume juvenile females need foster parents to feed them too, so do they also issue a similar call ?

        So far, the high-decibel Asian Koel calls that I overheard occur singly most of the time. In other words, only 1 bird (ie. the same bird) would call & do so incessantly. In the early morning when it is quieter, you can aurally follow the movement of the bird by its calls & the rustling of leaves. Only very occasionally would there be a similar call from another Asian Koel in the far distance.

        At my location, the Asian Koels call from tall bushy trees like Khaya senegalensis (Senegal Mahogany) & Syzygium grande (Jambu Laut). I’ve also walked into (quiet) adult males foraging/ hiding amongst thick shrubs beside the flyover during the daytime.

        I’d never seen or heard Crows in the neighbourhood though. Only Javan Mynahs (lots), Common Mynahs (very few), Rock Pigeons (lots), Sparrows (quite few) & sometimes Pacific Swallows. So whose nests are the Asian Koels using to lay their eggs in this case ? Do Asian Koels sometimes choose to use Mynahs’ nests as a substitute for Crows’ nests ?

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