Seow Boon Eu from Penang, Malaysia, photographed a juvenile Banded Bay Cuckoo (Cacomantis sonneratii) being fed by a Common Iora (Aegithina tiphia).

Obviously the iora is the foster parent of the much larger juvenile. The former has been tricked into incubating and brooding the cuckoo chick. Cuckoos are nest parasites, laying their eggs in the nests of a wide range of birds.

“I noticed that this juvenile is still begging for food from its foster parent, unfortunately I couldn’t see the feeding, because it was hidden and very high up in the canopy. Currently I’m still observing its feeding behavior, hope to get more information from the observation,” says Boon Eu.

An earlier post on nest parasitism can be viewed HERE and below under “Related Posts.”

This post comes courtesy of Seow Boon Eu of Bonyou.

“On July 28th, 2009, while conducting a bird survey at Pulau Tekong, I heard the insistent, begging calls of a young bird. Moving closer, I spotted a medium-sized, juvenile cuckoo hopping about the branches of trees at the edge of the wooded area. It was obviously a Cacomantis cuckoo of sorts.

“I managed a couple of poor shots as the cuckoo actively moved about. The lighting was rather bad due to the cloudy skies. It was obviously still being tended to but by whom? As I continued observing, the cuckoo moved into the denser part of the vegetation and its calling became more frantic. Through a gap, I was able to observe an adult Ashy Tailorbird Orthotomus ruficeps feeding the juvenile cuckoo.

“I remember seeing Common Ioras Aegithina tiphia feeding a juvenile Banded Bay Cuckoo Cacomantis sonneratii years ago and know others have also seen this. I know that a few others have also seen Pied Fantail Rhipidura javanica playing host to juvenile Rusty-breasted Cuckoo C. sepulcralis. [I don’t remember anyone observing a host for Plaintive Cuckoo C. merulinus in Singapore.] However, I do not recall anyone observing tailorbirds playing host to a parasitic cuckoo in Singapore. I decided to do some research.

“Wells (1999) mentions that for the Malay Peninsula, Common Iora is the only known host for Banded Bay Cuckoo outside closed forest and Dark-necked Tailorbird Orthotomus atrogularis and Yellow-bellied Prinia Prinia flaviventris are the only confirmed hosts for the Plaintive Cuckoo. He also states that there are no known confirmed hosts for the Rusty-breasted Cuckoo in the Malay Peninsula. [In the mid 1980s, I have observed an unidentified Cacomantis cuckoo being tended to by Golden-bellied Gerygone Gerygone sulphurea, at Pulau Tekong.]

“Robson (2008) lists the following hosts for each Cacomantis cuckoo, in South-East Asia.
1. Banded Bay Cuckoo – White-bellied Erpornis, minivets, Bar-winged Flycatcher-shrike and Common Iora; 2. Plaintive Cuckoo – tailorbirds, cisticolas, and prinias; 3. Rusty-breasted Cuckoo – Pied Fantail, Long-tailed Shrike, Olive-backed Sunbird, Pied Stonechat, Chestnut-naped Forktail, flycatchers and tailorbirds.

“Based on my poor cuckoo photos, I would lean toward it being a Rusty-breasted Cuckoo but am not entirely certain. I cannot recall reading or hearing about a tailorbird playing host to a parasitic cuckoo in Singapore. If this is true, then this may be the first local record.”

Subaraj Rajathurai
29th July 2009

References:
1. Robson, C., 2008. A field guide to the birds of South-east Asia. New Holland, London. 544 pp.
2. Wells, D.R., 1999. The birds of the Thai-Malay Peninsular. Vol. I, Non-passerines. Academic Press, London. 648 pp.

“I was in Vietnam in June 2008 at a mountain resort known as Mai Chau. It was disappointing for me that the birds there were dismally meagre. But I encountered something rather strange while walking round the parameters of the rice fields. There was a pair of what I believe to be Ashy Woodswallows (Artamus fuscus) flying about - see the picture with the grasshopper(?) in its beak. The first time round nothing out of the ordinary happened. But when I passed them a second time round they seemed extremely agitated - screaming very loud and flying rather erratically to and from the telephone wire. Curious I hung around with my compact camera ready.

“Then I noticed some fluttering movement in a bush just below the telephone wire. As I moved in to get a closer look, the pair up on the wire became even more and more agitated. It was then that I saw a nestling struggling amongst the leaves of the bush (left). It was obvious that it was not old enough to even stand up, let alone fly. How did it get there? No nest was obvious.

“We’ve all heard of how parents yell instructions to their young when they observe the latter in danger - Run! Hide! Hit!

“Well, on hindsight I think the parents on the wire were yelling to the nestling: “Stay still! Don’t Move! Play statue!” After some initial struggling, I saw the nestling taking a very strange pose. It seemed to align itself to a central stem to the extent of stretching its neck and beak upwards under a leaf - see the second picture. And there it stayed; and all went quiet with the parents.

“At that time I wasn’t sure what was happening nor what was going to happen. So I did nothing; I just hung around wondering if anything else was going to happen. But nothing did. The nestling held it’s pose without a squeak or a twitch. The parents flew around a little but never far away from the wire. After about 5 minutes or so, I left - dinner was calling me. The next time I strolled pass that spot all was quiet.

“That little incident left some questions for me. How did the nestling get there? The bush was on the edge of an open rice field with no trees anywhere near. Were the parents transporting it when it slipped from their grip and fell? Has such a unique survival strategy amongst birds been documented before?”

Lim Poh Bee
27th January 2009

Note by YC:
I may be wrong, but the fledgling looks suspiciously like that of the Asian Koel (Eudynamys scolopacea). Not sure what birds the koel parasitises in Vietnam. We welcome comments from viewers.

The Asian Koel (Eudynamys scolopacea) is a cuckoo, and like many cuckoos, it is a brood parasite. The female koel lays her eggs in the nest of one or more species of hosts, allowing the latter to incubate her eggs and feed her chicks until they are fledged and for some time after. In Singapore it has always been assumed that the Asian Koel’s host is the House Crow (Corvus splendens). Evidence that this was so only came in the mid-2000s (Wee, 2005).

The drama started in October 2003 when a pair of House Crows nested in one of my two ceram palm (Rhopaloblaste ceramica) growing in my garden. The outcome of this nesting was an Asian Koel.

Three months later, there was another nesting and again, a keol fledged from the nest. A third nesting was detected, again three months from the second. And yet again, no crows fledged. This time three koels fledged, the second a week after the first and the third, three days after the second.

I expected another nesting in July 2004, three months after the last nesting. Unfortunately the nest was ripped apart and the debris landed on my driveway. What caused this destruction was not known.

One month after this, an egg was found smashed on my driveway. Apparently a new nest had been rebuilt in the crown of the palm. On September 2004, two other eggs were found smashed below the palm.

After this incident, the crows did not return to nest.

I have always been puzzled by the above events, especially the destruction of the nest and eggs. The publications that I managed to read all say that Asian Koel does not eject the host egg or chick. The book by Davies (2000) specifically states that Asian Koel is among six cuckoos that do not eject the host eggs or young.

Then I came across the book by Payne (2005) where it cites Baker (1934): “The Koel may remove a host egg.” Apparently the koel’s shorter incubation of 13-14 days compared to the crow’s 16-20 days allows the former to hatch first and thus eject the eggs or nestling of the host. On the other hand there have also been cases of the koel nestling growing up together with those of the host. Payne (2005) also reports that two or more cuckoos sometimes fledge from a nest.

So it is very possible that the eggs that landed on my driveway in July 2004 could be the egg of the crow, pushed out by the koel chick.

However, a number of questions remain unanswered. Which bird was responsible for ripping up the nest in July 2004? What happened to the koel chick if, indeed, it did eject the crow egg in August 2004? Could the two eggs that were ejected in September 2004 belong to the crow? Did the crows abandon the nest after this, leaving the koel chick to its fate?

Unfortunately, birders in Singapore have never been interested in such observations and the few ornithologists around have other research priorities. However, a new breed of bird photographers is actively documenting bird behaviour that one day may provide answers.

Tang Hung Bun is one of them. In December 2005 he documented the contents of a crow’s nest that had a naked chick and an egg (top left). The next day when he checked the nest, he found only the egg, the chick was gone. Two weeks later, he checked and to his surprise found three eggs (top right).

Unfortunately, before he could complete his observations, the local Town Council people destroyed the nest. Part of our crow eradication programme.

Could the naked chick be a crow? Could it be subsequently removed by a koel? Did the koel return to lay one or more eggs? More questions to be answered!

Images by Tang Hung Bun.

References:
1. Baker, E.C.S. (1934). The nidification of birds of the Indian Empire, vol. 3. London: Taylor & Francis.
2. Davies, N. B. (2000). Cuckoos, cowbirds and other cheats. London: T&AD Poyser.
3. Payne, R.B. (2005). The cuckoos. Oxford University Press.
4. Wee, Y.C. (2005) Look, what came out of the crow’s nests. Nature Watch 13(1):22-25.

The Asian Emerald Cuckoo (Chrysococcyx maculates) has at long last been accepted by the Records Committee of the Nature Society (Singapore)’s Bird Group. This was formally accepted during its April 2008 meeting and reported in the Singapore Avifauna Vol. 22(8).

A female (top left) together with an immature bird (top right) were photographed by birder-photographer KC Tsang as far back as 31st May 2006 at Upper Seletar Reservoir and submitted to the committee.

The committee must surely be greatly relieved to be able to come to a decision after more than two years. This was with photographic evidence. What more, if the sighting was documented by sketches and field notes.

It has always been rumoured that in the past, unless a senior member of the Records Committee actually saw the bird, the sighting submission would not see the light of day. Of course, this is just a rumour. However, to be fair, how can you take the word of the not-so-experienced birdwatchers? Especially in the absence of photographic evidence!

As far back as 1998, the bird was listed as a resident in R Subaraj’s privately circulated Field Checklist of the Birds of Singapore. But the 1999 checklist complied by the Bird Group did not include it. Strangely, the bird was included in the Lim (1997) with the status of “not yet recorded from Singapore but a probable winter visitor.”

Subsequently, Subaraj made a sighting that he believed to be an immature Asian Emerald Cuckoo, but this was also rejected due to lack of evidence, although it was thought to be a Violet Cuckoo.

References:
1. Lim, K. S., 1997. Birds - An illustrated field guide to the birds of Singapore. Sun Tree, Singapore. 226 pp.
2. Wang, L.K. & C. J. Hails, 2007. An annotated checklist of birds of Singapore. Raffles Bulletin of Zoology, Supplement 15: 1-179.