On 8th February 2008, Simon Cockayne and Martin Kennewell spent a morning birding at Changi Cove (above). The highlight of their trip was seeing six to eight birds of the newly described “White-faced” Plover.

Simon sent in images of the Malaysian (left top) and White-faced (left bottom) Plovers that he digiscoped, the birds being some distance away.

As Martin writes: “We went in on the new road to the air show. The guard was very reasonable and allowed us entry, we did explain that we wanted to access the coast beyond the air show to go bird watching. We signed the visitor’s book and were given a visitors pass. We drove about two kilometres to where the road u-turns… that allows you to access the coast. It is then a further one kilometre on foot to the site.”

Their morning tally: Lesser Sand Plover (c250), Pacific Golden Plover (c150), Grey Plover (c50), Malaysian Plover (10), Kentish Plover (<5), Red-necked Stint (1), Common Sandpiper (4+), Common Tern (8), Terek Sandpiper (1), Oriental Pratincole (4 flying north), "White-faced" Plover (4 males, 2 non-males, plus maybe 2/3 more).

Note: The White-faced Plover is a “mystery” plover first observed by Peter Kennerley (in Singapore, 1993-4) and David Bakewell (in Malaysia, 2006-7) and described in an article published in Surfbirds.com.

These birds occur during the northern winter months of October to March together with flocks of Kentish Plovers (Charadrius alexandrinus), and like the latter, appear to undertake a pre-breeding moult between January and March, suggesting a northern origin. After considering the possibilities of them being hybrids (Kentish x Malaysian), having aberrant plumage or being a poorly known race of a common species, or even an undescribed taxon, the authors concluded that it is most probably a new taxon. However, they suggest that detailed comparison of biometrics and DNA of these birds with those of known taxa be undertaken for comparison.

On 17th August 2007, Ong Tun Pin sent an image of a curlew, commenting, “I have just come back from a 10 day trip to a very exotic island destination.

“Attached is a whimbrel-like wader that I hope you can guess as the name can be derived from one body feature shown in the picture (above). I know that wader is usually hard to id but this one has one famous body part that gives its name. Not found in Southeast Asia but at the edge of the oriental region.

“Would be nice if someone could tell me if this is a juvenile and whether it is in moulting. I was told that this bird becomes temporarily flightless during wing-moult. It was reluctant to fly and I was able to do some sort of wader ‘herding’ along the beach. But one still flew away after I have ‘cornered’ it at sand banks at 4 meters away. This is not the way we do wader-watching in Malaysia where often a combined effort of scoping 60x from far distance and lurking among tall grass still scares the waders away”

It was an image of a Bristle-thighed Curlew (Numenius tahitiensis), a rare bird whose breeding population is concentrated on the mountain tundra in West Alaska. It is called bristle-thighed because of the elongated feather shafts seen at the rear flanks and thighs (left). These long, shiny ‘bristles’ are usually seen only when the bird is handled. However, Tun Pin was fortunate to have captured this feature in his image, a feature he could not see through the lens. This again shows the importance of photographic images in the study of birds and bird behaviour.

The bird winters exclusively on oceanic islands, especially small Polynesian islands. And this was where Ong Tun Pin encountered the curlew, when he was on a ten-day holiday in Tahiti in August 2007.

This is a highly migratory bird, making long distance, non-stop flight of at least 4,000 km over the open ocean. The adults begin to leave their breeding grounds from early July, followed by the juveniles in early August. They meet at their staging grounds on central Yukon Delta before migrating to their winter grounds in the South Pacific islands.

The image above of the flying bird shows its chestnut rump without stripes. This is the diagnostic feature to separate it from Whimbrel (Numenius phaeopus).

In the wintering grounds (left), the bird moults and about 50% of the adults become flightless for about two weeks. This is the only shorebird known to have a flightless moult. This is not a problem where they winter in remote islands where there are no predators. However, when humans settle on these islands, the flightless moulting birds are at a serious handicap, especially with the introduction of domestic cats, dogs and even pigs.

The adults depart in early May while the immature birds spend all of their pre-breeding years on the wintering grounds.

Input and images by Ong Tun Pin.

References:
1. Gils, van J. & Wiersma, P. (1996). [‘Family Scolopacidae (Sandpipers, Snipes and Phalaropes]. Pp. 444-533 in del Hoyo, J., Elliott, A. & Sargatal, J. eds. Handbook of the birds of the world. Vol. 3. Hoatzin to Auks. Barcelona: Lynx Editions.
2. Kaufman, Kenn (1996). Lives of North American birds. Boston & New York: Houghton Mifflin Co.
3. Rosair, D. & Cottridge, D. (1995). Photographic guide to the waders of the world. London: Hamlyn.

On 24th February 1990, Volker Konrad encountered and photographed a plover new to Singapore at Changi. He sent his observation, including a picture, to the Singapore Records Committee set up by the Bird Group of the Nature Society (Singapore). The committee identified the bird as a Long-billed Plover (Charadrius placidus). This was reported in the Singapore Avifauna 11(4) that appeared only seven years later.

Subsequently Konrad published his finding, based on the identification provided, in the Oriental Bird Club’s scientific journal, Forktail (2005).

In the December 2006 issue of the OBC’s bulletin, BirdingASIA, Paul J. Leader, a birder based in Hongkong, successfully challenged the identification of the bird. According to Leader, the bird seen in Singapore way back in 1990 was actually a Kentish Plover (C. alexandrnius), not a Long-billed.

Konrad, the birder who sighted the bird at Changi, has so far retracted his published record and according to Birding ASIA, “…the Singapore Records Committee (Nature Society Singapore) now agrees that this record concerns the Kentish Plover.”

Well and good. A mistake has been rectified. There were no ornithologists in the Singapore Records Committee then, only experienced recreational birders. Even if there were, the best of ornithologists do sometimes make mistakes in identification.

It may therefore be a good idea if in future, to avoid mistakes as much as possible, the photographs of rarities reported are sent for their opinions to leading ornithologists overseas who have long experience of birds in Asia.

According to our bird specialist, R. Subaraj, “To put everything in perspective, regardless of the status of local records, the only confirmed Malaysian record is of one at Tanjong Rhu, Pulau Langkawi, on 19th March 1968 (Wells, 1999).

“This far south, many vagrants occur in heavily moulted, winter or juvenile plumages and this emphasises the value of exercising great caution when considering such records. One must always seek advise from those with greater experience and knowledge of such birds!”

References
Konrad, V. (2005). First record of Long-billed Plover Charadris placidus in Singapore. Forktail 21:181-182.
Leader, P.J. (2006). Comments on the purported first record of Long-billed Plover for Singapore. BirdingASIA 6: 45-47.
Wells, D.R. (1999). The birds of the Thai-Malay Peninsular. Vol. I, Non-passerines. Academic Press, London.

The breeding ecology of the Little Tern (Sterna albifrons) was posted as a five part series earlier - 1, 2, 3, 4 and 5.

Jonathan Cheah and Ashley Ng were both involved in documenting the series during the entire nesting period of about five weeks. Two photographers were necessary in order to minimise disturbance to the nesting grounds.

The birds feed as a flock, leaving the nests unguarded during this period. It was then that each nest was marked with plastic pickets as otherwise it would be difficult to relocate them. Also, this would prevent accidental trampling of the nests. Even after hatching, there was the constant danger of stepping on the chicks as they remained camouflaged, lying low and still. As far as were possible, defined paths were used, especially when moving down the valleys, to further minimise accidents. A total of about 60 eggs were counted from the various nests, of which about 75% of the chicks that hatched survived. Those that did not survive died within a few hours of hatching. A number of chicks were victims of feral dogs that roamed the area. Some eggs remained unhatched, mostly from clutches of more than two.

Documenting the birds was not easy as the parent birds were constantly dive-bombing the intruders. There was also the loud screeching of the birds as well as the echoes of the cries from above bouncing off from the sand to contend with.

All these distractions were enough to confuse predator and allowed the chicks to get into the shadows or among the vegetation. But obviously not the photographers, who persisted in order to being back the images.

Input and images by Dr Jonathan Cheah Weng Kwong.

The various aspects of the breeding ecology of the Little Tern (Sterna albifrons) have already been posted earlier - 1, 2, 3 and 4. This, the fifth part, deals with the chicks’ evasive tacticts in trying to stay undetected. From day two onwards, the chicks are actually mobile. However, they choose to stay on the nest mound for longer periods for feeding (above). Within hours they can move down the corners of the mound to the valleys or even hide among the vegetation (above). This is especially dangerous as photographers have earlier learnt to avoid the tops of mounds. Hence during hatching time, the valleys and vegetation need to be checked with much caution. When chicks spot predators, they usually disappear into the shadows whilst the adults call overhead and perform dive bombing. This allows the chicks time to move to cover and remain motionless. They are rather clumsy at times. As they grow larger, they will continue to use vegetation as cover (below). Parents get into dive bombing mode with shreaks and calls to drive predators like dogs and other birds away from the vicinity of the hiding chick (bottom left). The chick only opens its mouth for food and stay still. The rest of the adults wll sound the alarm for all the rest of the hiding chicks to remain motionless.
Once the threat is gone, the chick will slowly turn its head to locate the next hiding place. It will check two to three times to ensure that there is no more threat before making a quick dash for the next cover. When it senses that predators are approaching, it will remain stationary irregardless of whether it has reached a safe location or not (above). The aerial distractions are the main source of challenge that makes detection of the chicks hard.

Input and images by Dr Jonathan Cheah Weng Kwong.