“We have known the location of the roosting site of the Glossy Swiftlets (Collocalia esculenta) on Fraser’s Hill for many years now. It is such a common bird there but without any exceptional colour pattern or design to attract our attention, we have left this species out of our radar scan.

“However, I have recently become aware that there could be more species of swiftlets in Singapore’s airspace than a lot of us realise. So I am curious about swiftlets. Then there was a chance meeting with Mr. Ken Scriven, a long time friend, on the road in Frasers’ that set me looking at the Glossy Swiftlets.

“Ken alerted me that at 7.30 pm in front of the roosting site, there would be a great gathering of Glossy Swiftlets, about 3,000 birds he said, buzzing around to get into the small man-made “cave”, a disused garage actually. To be honest, we think that there were about a couple of hundreds, but this did not make the event any less exciting.

“Anyways, while waiting for the event to start, I decided to look into this cave - man this place sure stinks to high heaven, with all that guano collecting on the floor. Then I realised that these birds had to do some incredible flight maneuvers in order to secure itself on to the ceiling of the garage.

“However, before these birds could get into this man-made cave, there was one obstacle that they had to get through, that is the grilled gate of the garage. The bars are constructed vertically, and about five inches apart. These birds would have to fly in at a very high speed without knocking themselves silly on the bars. So far from our observations, we did hear a few clunks, nothing serious that would cause the bird to floor themselves.

“While in the so-called cave, the birds would be circling anti clockwise, round and round; they somehow knew that they had to go around in one direction; then one or two would decide that it was time to rest and would attempt to secure itself onto the ceiling. This bird would fly to a higher level where there were no flying birds, hovered in mid-air, flipped around upside down, used its beak to secure itself onto the ceiling which would have a tiny beak hold. Once the beak was secured, it would then flapped its wings in a special way to bring the rest of its tiny body up to the ceiling so that the claws of its feet would also be able to find a place to further secure itself. All these maneuvers were done in some split seconds.

“Now if the bird is to decide that it needs to build a nest, it would then secrete a translucent kind of sticky gel on to the ceiling and attach a kind of string-like grass to the gel. As you can see, it is an extremely difficult task, the bird will have to make so many trips to collect the grass, and fly back to the same spot to continue the process of building the nest. I am just wondering what would happen if some other bird decides to hijack that same spot.

“This swiftlet can be found commonly in Malaysia, Brunei, and the Philippines, but considered to be rare, resident breeding not proven, and a nationally threatened species in Singapore.”

KC Tsang
Fraser’s Hill, 17/02/2008

In birding as in any other activities, there are those who are conservative and those who are ultra-conservative, preferring the status quo.

This is exactly the situation with the controversy on the existence of the Himalayan Swiftlet (Aerodramus brevirostris).

As early as the late 1980s, Richard Ollington was one birder who was totally convinced of the presence of the Himalayan in Singapore. A highly respected and well-quoted birder, he published his observations in his privately circulated Singapore Bird Reports (1992, 1993). Circulation was restricted but copies were made available to ornithologists. Chantler (1999) and Wells (1999) quoted him, with the latter recording that Himalayan Swiftlets were seen making “active passage over Singapore.”

R Subaraj, another experienced and well-respected birder, has also been convinced of the Himalayan’s presence for a long time now. However, most other birders simply ignored the controversy, as swiftles, especially Himalayan, are not all that easy to study and ID.

Ollington and Subaraj did not officially provide details of the swiftlet to the Nature Society’s Records Committee. They refused to work within the system as, according to Subaraj, “it is a lack of faith in the bird records committee” and it would be “a waste of time to submit anything.” Also, the committee was said to have adopted “highly debatable methods of acceptance and decision-making in the past that were simply unacceptable!”

So the Himalayan did not make it into the official checklist.

However, Subaraj wanted to make his point that the species was abundant and could be seen regularly, as well as to “…inspire some others to look harder at swiftlets…” So at every Bird Race he listed Himalayan Swiftlet with accompanying notes as one of his observations, even though he was sure the arbitrators would reject it. The arbitrators did reject his team’s entry at every race as the species was not in the official checklist - see Alan OwYong’s comments.

So birders have always been aware of the controversy but none were willing to meet the challenge… until now. KC Tsang, at the encouragement of bird group activist Alan OwYong, went into the field and brought back crisp images of what he believes to be Himalayan. This is the first time local birders are confronted with such images of this swiftlet.

Referring to his past inclusion of the Himalayan at every bird race, Subaraj added: “This was all in vain or was it? If Alan OwYong pushed KC into photographing swiftlets, it may have something to do with this, as he was the bird race coordinator in 2006.”

KC has, on 8th January 2008, officially submitted his records to the Nature Society’s Records Committee for consideration. Faced with KC’s official submission, the Records Committee is at last forced to act. It needs to deliberate and come to a decision soon. Unfortunately, none of the committee members are familiar with the Himalayan, with the exception of Yong Ding Li, an up-and-coming young and energetic birder. Ding Li is also the editor of Singapore Avifauna (see 1, 2, 3 and 4), a privately circulated newsletter of the Nature Society’s Bird Group.

Ding Li is one of the few birders brave enough to recently come forward in support of the Himalayan Swiftlet. He has, in fact identified the species in the field, around the fig tree at the summit of Bukit Timah and at *Panti Forest in neighbouring Johor, Malaysia.

I have been informed that members of the Records Committee are trying hard to get assistance from experts overseas based on KC’s images. Hopefully the controversy can be resolved officially one way or the other. The decision can only be: yes, no, or don’t know.

Whatever it is, the committe needs to come to an official decision, and soon!

*You need your Yahoo ID and password to access this OrientalBirding site.

References:
1. Chantler, P. (1999). [‘Family Apodidae (Swifts)’.] Pp.388-457 in del Hoyo, J., Elliott, A. & Sargatal, J. eds. Handbook of the birds of the world. Vol. 5. Barn-owls to hummingbirds. Barcelona: Lynx Editions.
2. Chantler, P. (2000). Swifts. A guide to the swifts and treeswifts of the world. New Haven & London: Yale University Press. (2nd ed.)
3. Lekagul, B. & Round, P.D. (1991). A guide to the Birds of Thailand. Thailand: Saha Karn Bhaet Co. Ltd.
4. Ollington, R.F. & Loh. E. (1992). 1991 Singapore Bird Report. Privately circulated.
5. Ollington, R.F. & Loh. E. (1993). 1992 Singapore Bird Report. Privately circulated.
6. Ollington, R.F. & Loh. E. (1996). Karimun Besar recent birdlist, updated to 01.04.96. Birdline Singapore Monthly Newsl. 43.
7. Wang. L.K. & Hails, C. J. (2007) An annotated checklist of birds of Singapore. Raffles Bull. Zool. Suppl. 15:1-179.
8. Wells, D.R. (1999). The birds of the Thai-Malay Peninsular. Vol. I, Non-passerines. Academic Press, London.

The sighting of the purported Himalayan Swiftlet (Aerodramus brevirostris) together with a clear image of the bird shot from below by KC Tsang as evidence, has been reported earlier (left top).

I took the liberty of sending KC’s image to Dr David R Wells, author of “The Birds of the Thai-Malay Peninsular” and he kindly sent this reply:

“Good to hear from you, and thanks for the photo. The experts may indeed be sitting on the fence, but I do have to say that identification of the Peninsula’s grey (Aerodramus) swiftlets, from a still shot, particularly one taken from below, is hit and miss. THUS FAR, no-one has come up with a way of being certain. What I will admit is that the tail-fork is deeper, more conspicuous than I would have expected in a White-nest and certainly more so than in a Black-nest – leaving HS as the best bet.

“Seen in life, flocks of swiftlets with uniformly conspicuous tail-fork (such as shown) and rather stiff wing-beat I have tended to assume were HS, and passage movements of such birds have been noted over the S end of the Peninsula, including Singapore.

“Beautiful picture, nonetheless, and one of these days it could contribute to working out something more useful by way of ID characters.”

Black-nest (A. maximus) and White-nest (A. fuciphagus) are both common residents, the latter is also known as Edible-nest.

KC managed to get an image of the bird from above some time later (left bottom) and again I sent the image to Dr Wells. His response:

“Presumably not the same individual as before as tail-fork less pronounced (or it appears so; photos can be deceptive). All I will say is that any bird with a rump this pale relative to the rest of the upperparts, as far south as Singapore, could hardly be a White-nest. Given that Black-nests have the squarest tail of the three, the odds are in favour of Himalayan. BUT, this ID is still only statistical.”

In the absence of a live or dead specimen (or possibly more than one) in hand, the above images could be considered those of the Himalayan Swiftlet - all things considered.

Images by KC Tsang and comments by Dr David R Wells

References:
1. Robson, C. (2005). Birds of South-east Asia. London: New Holland.
2. Wang. L.K. & Hails, C. J. (2007) An annotated checklist of birds of Singapore. Raffles Bull. Zool. Suppl. 15:1-179.
3. Wells, D.R. (1999). The birds of the Thai-Malay Peninsular. Vol. I, Non-passerines. Academic Press, London.

On 7th January 2008 at 1047 hours, KC Tsang was witness to a number of Himalayan Swiftlets (Aerodramus brevirostris) among a flock of swifts and Barn Swallows (Hirundo rustica) hunting for insects stirred up by grass cutting activity at the grounds of Turf Club City. The number of birds hovering around was about 50.

The occurrence of Himalayan Swiftlet in Singapore has been mired in controversy since the 1990s when R. Subaraj, among others, first reported it as an uncommon passage migrant (Wang & Hails 2007). Unfortunately these observations were not authenticated with notes and thus not included in the latest Annotated Checklist of the Birds of Singapore.

Now, KC has provided hard evidence in the form of an image. He posted his image in BirdForum.Net and got a response from Sean in Hiroshima, Japan, who noted:

“…think there are four possible swiftlet species in Singapore. …Two are resident - Black-nest and Germain’s while two are migrants - Glossy and Himalayan.

“I have only seen three of the species, Black-nest, Germain’s and Himalayan, but Himalayan seems right to me for the following reasons.

“Glossy can be ruled out, as it is very small, has dark throat that contrasts with white belly and a slightly forked tail. Black-nest is darker underneath and has no notch in the tail. It also has a pale rump band, though this cannot be seen in the picture. Germain’s is possible as it is light underneath on throat and belly, but as it only has a shallow forked tail this seems unlikely. This species has a very obvious wide white rump, though again this is not viewable in the picture.

“So Himalayan with its relatively pale underparts and deeper notched tail seems most likely, They do have a paler area on the rump in some races, but never as white or obvious as Germain’s or even Black-nest.”

Most of the experienced younger birders are confident that it is Himalayan but the older ones are rather hesistant to give their outright support.

Except Subaraj, who is naturally jubilant, that he has been right all along: “Nice shot! Pity that you did not manage a shot of the upperparts as well but based on the curved, pointy wings and prominent tail notch, I would agree that this is a Himalayan Swiftlet.

“I cannot be certain of which race you have photographed though as there is no view of the upperparts and the colouration of a photo is not always the exact colour of the actual bird.

“Based on my observations over the years, the Himalayan Swiftlet is one of our commonest migrants. Most pass through on passage but birds can be seen throughout the wintering months. They can be seen anywhere in Singapore and Johor. Birds on passage can regularly be observed at various sites including MacRitchie, Changi Reclaimation, Serangoon, Tanjong Piai, Bintan or even on a boat between Singapore and the Riau Islands. At the Gap, at Frasers, hundreds can be observed moving through with Fork-tailed Swifts during passage.

“I have identified two races here; the nominate race brevirostris, which is very common on passage and in smaller numbers during the mid-winter period and the race rogersi (sometimes treated as a separate species called the Indochinese Swiftlet), which is mainly a passage migrant in small numbers.

“The nominate race appears slightly larger, is darker above with a narrow wide rump band, and a longer trail and wings. C.b.rogersi is slightly shorter winged and tailed, has a brownish wash to the upper plumage and the broader rump is buff. Both are prominently notched, in the tail.

“Most birders here live with an old-fashioned mind-set and still refuse to accept that this species can be readily identified in the field. That is why you will not find it on the NSS BG’s checklist. It has been on my personal bird checklist for nearly a decade now. Elsewhere in the world, birders have no problem identifying this species in the field. They work hard with better optics and field id guides, to resolve the field characteristics of similar species. I spent years doing the same here but the so called “powers to be” scoffed at anything that they themselves have not bothered learning to identify!

“I will continue operating outside the box and am glad that you have chosen to do so too.”

In May 2007 Melinda and Meng came across a pair of nesting Grey-rumped Treeswift (Hemiprocne longipennis) in a patch of secondary growth in the north of the island. They built their nest attached to a slender branch of an acacia tree (Acacia auriculariformis) some 20 metres high. The sexes are easily distinguished, with the male having rufous ear-coverts (left top) and the female blackish ear-coverts (left bottom).

The nest is a half-saucer made from hardened saliva incorporated with feathers, mosses and flakes of tree bark. Ornithologists believe that the feathers come mostly from the bodies of the birds themselves.

Chantler (2000) reports that the single egg laid is stuck to the nest surface with saliva. And because the nest is so frail and delicate and only attached at its side to the branch, the bird does not sit directly on the nest during incubation. Based on the images obtained, the weight of the bird was obviously not wholly on the nest. It was sitting on the branch and had its tarsus over the nest with the talons clutching the nest edge. This position allowed the brood patch to make contact with the egg. Gibson-Hill (1950) has similarly reported that the parent birds brooded by perching on the branch above the nest and fluffing their breast feathers out to cover it.

Both birds helped incubate the egg. Melinda and Meng witnessed the changing of shift three times, at 1.20 pm, 1.30 pm and 1.40 pm on three different days. Each time the female flew in and carefully perched besides the incubating male (below left). The male then flew off and the female carefully slided over the nest (below right). On one day there was no bird incubating the egg at 1.00 pm. However, 20 minutes later the female flew in and settled on the nest. Unfortunately, before they could observe when the male flew in to relieve the female for incubating duty as well as make other observations, the tree was heavily pruned and the nest destroyed.

At shift changing time, the incubating bird flew off at an angle, dropping backwards. This no doubt helped minimised the chances of the feet lifting the egg from its shallow bed as the bird flew off. Again, this is consistent with the observation made by Gibson-Hill (1950).

The images below by Daniel Koh of the bird at rest clearly show the characteristic long wing tips crossing over the shorter forked tail.

Some details of the nesting have been posted earlier.

Input by Melinda Chan, YC and Wang Luan Keng; images by Chan Yoke Meng except bottom panel by Daniel Koh.

References:
Chantler, P. (2000). Swifts. A guide to the swifts and treeswifts of the world. New Haven & London: Yale University Press. (2nd ed.)

Gibson-Hill, C. A. (1950). A note on the Crested Tree-swift. Malayan Nature Journal, 5: 5-8.