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Thursday, June 29, 2006

Collared Kingfisher and the caterpillar

Collared Kingfisher and the caterpillar

I was out photographing the nesting of a pair of Scarlet-backed Flowerpecker (Dicaeum cruentatum) when I noticed localised movements in the backgtound. On closer look, I saw a bluish bird hovering vertically below some branches, like a ballerina doing an en pointe, but in the air. It was just an unusual manouvering of a Collared Kingfisher (Todiramphus chloris), doing what, I had absolutely no idea.

It was after some attempts that the bird finally achieved what it set out to do. And that was to get at a large and succulent caterpillar that was sitting quietly on a branch of the tembusu tree (Fagraea fragrans). The bird then perched on a nearby branch and began to bash the caterpillar against its perch, possibly to remove its head and empty its stomach contents.

When the bird was on its perch with the caterpiller between its beak, things became obvious. But only after I processed the images that were captured in the field did I notice more details. The images above clearly show that the bird had a caterpillar firmly between its beak. The next question was to ID the caterpillar. To which moth or butterfly does it belong to?

Again an image helped solved this question. There were various suggestions when an image of the caterpillar between the beak of the kingfisher was posted on the BESGroup and other e-loops. A few suggested that it was a hawkmoth caterpillar, and indeed it was. Leong Tzi Ming finally identified it as the caterpillar of Psilogramma menephron (Family Sphingidae), the Privet Hawk Moth. The green caterpillar with white diagonal stripes is commonly known as hornworm because of the presence of a horn at the end of its tail. It is among the largest of caterpillars, growing to a length of 8-12 cm. Without the image, the kingfisher will be recorded as catching a big fat caterpillar!


Thanks to Leong Tzi Ming for the ID and to KC Tsang, Jacqueline Lau, Robert Teo, Steven Chong, Margie Hall, Vilma d'Rozario and others for their input. Images are by YC.

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Tuesday, June 27, 2006

Breeding Distraction 1: Masked Lapwing

Breeding Distraction 1: Masked Lapwing

While visiting the Hobart Botanical Gardens, Tasmania in Dec 2005, Teo Lee Wei and family “came across a pair of birds about the size of crows. They were running and flying very low, calling in distress and visibly stressed. Their antics seemed like some distracting ploy. Then we noticed five little chicks running helter-skelter in all directions but generally towards the parent birds.

“We managed to get near two little chicks and when we were within a metre of them they promptly sat down. Managed to snap the picture of one that was very well camouflaged. All the while the parent birds kept up their high-energy and high-decibel antics. When we moved a little away from the chicks, the two got up and ran towards the parents.
“Throughout the two hours we were there the same thing happened without a break.

“When we returned the gardens the following day, we witnessed the same thing. We wondered why the parents chose a well-walked area to raise their brood when there were so many quiet corners in the huge garden grounds.

“When we visited Grindewald (Swiss Village) near Launceston we saw many of these birds near the roadside. The coach driver said they are Australian road runners. We did not see any little chicks running around or their antics.

“The episode reminds me of my own antics while raising my son. Humans share a lot of genes with birds I understand. Maybe I'm bird-brain wired and so can empathise with them.”

Note: The bird is actually a Masked Lapwing (Vanellus miles). They are very noisy, making a loud ‘kekekekekek’ call. The nest is a scrape in the ground, lined with grass and small twigs or unlined. The nestlings quit the nest within a few hours of hatching, to be led away by the parents to shelter. They are defended vigorously, the parent birds diving at intruders with a daunting screaming chatter.

Text and images by Lee Wei.

Sunday, June 25, 2006

Hougang's Hell For Hornbills

Hougang's Hell For Hornbills

I cannot begin to describe how heavy my heart felt recently when I found two huge Blyth's Hornbills being crammed into a tiny cage and put on sale at Chua's Pet Trading in Hougang. If there is any proverbial cupboard where skeletons are to be found in 'First World' Singapore, Hougang is one. It's the 'Guantanamo Bay' of Singapore... and freedom is taken away for no other crime than being 'wild and exotic' birds.

What else can I say? : (

Beyond what I have just wrote, how do I begin to describe the intimacy with which our own freedom are tied to theirs? I am truly lost for words.

However, let me share this photo (above), and invite you to step back in time with me and witness how insistent the hornbills were at biting the cold hard wire of the cage. They just want to be free; as free as all wild birds are born to be.

Would you, my dear sentient friends, share your thoughts and feelings with me too? I look forward to post them faithfully here. Thank you.

WHEN THE BUYING STOPS, THE TRADING WILL TOO!

©Joseph Lai 2003

The above has been posted at the request of Joseph Lai to let as many people as possible know about the cruelty of this trade.

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Friday, June 23, 2006

Attacked by White-bellied Sea Eagle

Attacked by White-bellied Sea Eagle

K.C. Tsang, an avid birder and photographer, was walking along a grassy area in Ponggol when a juvenile White-bellied Sea Eagle (Haliaeetus leucogaster) (also known as White-bellied Fish-Eagle), decided to check on him. In KC’s very words: “From high above it swooped down. Lucky for me I noticed what the fellow was doing, pointed the camera at it, it did an air-braking action, its talons already extended.”

KC did manage to get one dramatic shot of the bird as it was coming at him, as shown here, uncropped! I suppose it was worth the excitement and the risk of losing his baseball cap. But was the bird aiming for his cap? Was it hoping for a bigger catch?

After being frightened off, the bird circled KC a few times as he kept walking, his heart no doubt pounding. KC had more chances to make some more close shots, but I suppose the excitement of losing his cap and all caused him to get only blurred and over-exposed images. His D50 Camera did not react fast enough “Or maybe I should have lifted my finger off the trigger to let camera readjust itself.

Daisy, a Malaysian birder, wrote: "Obviously, this juvenile can’t tell the difference between a mouse and a human being wearing a baseball cap. I've been told raptors have been known to swoop at humans and cause scarring injuries. You are lucky! (Next time walk wearing a helmet). And what a flying shot you got there.”

Read about other attacks by House Crows: 1 and 2.

Thanks, KC for the exciting account and use of the image; and Daisy for the comment.

Thursday, June 22, 2006

Rainbow Lorikeet 1: A future pest in Singapore?

Rainbow Lorikeet 1: A future pest in Singapore?

A few months back Jeremy Lee wrote: “I was in Perth in 2001 when I though it might be a good idea to find out how I could legally bring back a pet Rainbow Lorikeet (Trichoglossus haematodus) to Singapore. There were plenty of birds to adopt from those animal refuge centres. However, the paperwork was daunting, besides this bird is in the CITES species list.

“I think this bird should be more correctly taken out of the CITES list and put on the banned potential immigrant list :P

“At that point in time, I was wondering how could this bird be endangered when there were so many in Australia? They were even nesting in downtown palms!

“The New Zealanders have been trying to get rid of them. As an alien species the bird is creating havoc to the local species.

“If it is as tough a species as I take it to be, once a breeding colony is established in Singapore from birds escaping from the pet trade (or owners giving them up because of their messy feeding habits), in ten years time I may be seeing Rainbow Lorikeets flying around instead of Red-breasted (Psittacula alexandri) or Long-tailed Parakeets (Psittacula longicauda).”





















Robert Teo agrees that this bird can be a problem, just like the Red-breasted Parakeet (top left) that is displacing our native Long-tailed Parakeet (top right). Similarly, Lim Jun Ying feels that much as immigrant birds may be better suited to their new environment, they do not belong. He cites the example of the Brown Tree Snake that was accidentally introduced into Guam. Within a few years, it drove eight out of the 11 or 12 endemic bird species to extinction.

KC Tsang thinks otherwise: “Birds like the Rainbow Lorikeet should not be considered a pest as it is behaving in ways that nature has destined it to do, and to survive as best as it can… But I cannot say this for crows, as they are true pests by any human definition.”

Our bird specialist, R. Subaraj has the final word: “Rainbow Lorikeets has been flying free for some years now. Besides the regular birds at the Singapore Botanic Gardens, they have also been recorded from a few other places such as Loyang, Upper Thomson and Pasir Laba.

“However, despite being around for some time now, they seem to have difficulty establishing themselves in Singapore. And it was not until last year that we actually have a reportedly successful breeding record. The previous nesting failed, due to predation by a monitor lizard. We are still monitoring the situation. However, there is no cause for alarm just yet.

“Besides Rainbows, other lory species have also been recorded free flying here, including at least a couple of species from the Red Lory complex of Indonesia.

In a country such as Singapore, where bird trade is a staple business, escapees are prevalent and diverse. For decades we have been concerned about the Javan Myna (Acridotheres javanicus) and the House Crow (Corvus splendens) feral populations. A few new introductions are beginning to take over parts of Singapore but the authorities are not too concerned as they have yet to become pests to humans.”

Thanks to Jeremy Lee, Robert Teo, KC Tsang, Lim Jun Ying and R Subaraj for their input. Images of Rainbow Lorikeet perching on a branch of the Golden Penda (Xanthostemon chrysanthus) tree (top) in Singapore, Red-breasted (bottom left) and Long-tailed Parakeets (bottom right) by YC.

Tuesday, June 20, 2006

Deformed bill

Deformed bill

While holidaying in Pangkor Island, Malaysia in May 2005, Susan Wong caught sight of an Oriental Pied Hornbill (Anthracoceros albirostris) with a deformed bill. With such an unusual bill, the bird obviously would have problems feeding. Yet, considering its size, it would appear that it had not fared badly. Still, Susan wondered how the bird picked up its food.

I am not sure whether there are any earlier reports of birds with deformed bills coming from Malaysia and Singapore. However, there are dozens of observations by birders in the United States on beak deformities in chickadees (Parus spp.). Most of these come from feeder-watchers, people who set up bird feeders in their gardens to attract birds.

In most deformities the upper and lower mandibles are longer than usual, with the upper longer and decurved.

Scientists are still not sure what causes these deformities. One theory is that food may be a factor. The hardness of the food a bird eats can regulate bill growth. This is because bills, like fingernails, are soft structures that grow at a constant rate. Thus the harder the food, the more wear and tear the bill undergoes. And regular bill use keeps bill growth in check. Other than diet, injury, diseases, and parasites can affect bill growth.

It would be interesting if other birders visiting Pangkor Island can make observations on the feeding habits of this particular hornbill.

R. Subaraj, our bird specialist, reports that several years ago, he observed a Terek Sandpiper (Xenus cinereus), a shorebird with upturned bill, with a deformed, downcurved bill, in Punggol (Sungei Serangoon). This same bird turned up at the same spot for two winters, indicating that the bird had learnt to cope with its handicap and feed sufficiently well to not only survive for at least a year, but also managed to undertake at least two autumn migrations (south) and one spring migration (north).

Thank you Susan, for this rare image and note.

You can get more information on bill deformities at this web site.

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Sunday, June 18, 2006

Life around a rotting tree trunk 5: The final chapter

Life around a rotting tree trunk 5: The final chapter

By the end of April the top portion of the rotting trunk at Eng Neo collapsed due to the continuous rainy weather (left). This meant that the cavities used by the various birds were there no more. The top portion of the trunk where the Dollarbirds (Eurystomus orientalis) nested, was buried in the ground when it collapsed, probably trapping the nestlings. The Collared Kingfishers' (Todiramphus chloris) nest, found lower down the trunk, was at the point of the break and not buried. A nestling was found at the base of the trunk, dead, while another was alive. Sreedharan Gopalsamy was there at this final chapter and gives his account:

“The Eng Neo area has been a favourite for birdwatchers and photographers in the month of April and early May due to the Hornbill sightings and the nesting of several species including the dollarbird and the collared kingfisher.

“On 30th April, I was over there photographing the Dollarbirds and their antics. When I moved over to the nesting tree I realised something was amiss. A huge chunk of the tree trunk had disappeared. Together with it, the nests of Dollarbird and Collared Kingfisher. The kingfisher parents appeared every 10 minutes searching for their nest to no avail. They kept going to the wrong "hole". They could not comprehend why the juveniles could not be found.














"Later, a friend, Philip, and I decided to investigate further. Looking around, Philip spotted something bluish hopping amongst the tall grass. It turned out to be a very tired and disoriented juvenile Collared Kingfisher. I made a quick call to Ashley who, as it turned out, was at Ayer Keroh at that time. He suggested us taking it to Sungei Buloh Wetland Reserve or Jurong Bird Park and handing it over to them for subsequent nursing.

“A further look around and some calls later allowed us to figure out what had happened. All was fine on the 29th till late afternoon. The heavy rainstorm that night caused the large part of the trunk, just below the kingfisher’s nest, to break-off and plunge towards the ground. The falling part broke into several pieces upon impact. The top end was impaled into the ground. This was the Dollarbirds' nest. Despite all our efforts, we could not budge the buried trunk and so any Dollarbird chicks would have been buried alive. After a look around, I located the broken stump with the kingfisher nest. As the nest was not covered, it allowed the poor shell-shocked juvenile to escape. Looking around the nest I found a dead sibling (of the juvenile) who had probably died some days previously but not from the impact.

“Philip decided to take the juvenile home and nurse it. He fed it with worms in the first couple of days and included little frogs in its diet subsequently. By 2nd May the juvenile could fly a few meters. On 3rd May, the juvenile was strong enough to fly off and start its new life on its own.”

Thanks Sree for the most interesting account of the final chapter of the Eng Neo saga. All images by Sree except top by YC.

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Friday, June 16, 2006

Feather maintenance: Preening

Feather maintenance: Preening

Birds spend a large portion of their time preening. This involves fluffing its feathers and then using its bill to comb them. Preening aligns the barbs and barbules that make up the feather vane and ensures that they are properly interlocked. At the same time the bird applies a waxy oil that comes from the preen gland found at the base of the tail, spreading it all over the feathers. This oil, once thought to waterproof the feathers, is now believed to keep them from drying out and becoming brittle. The oil also deters feather parasites like bacteria, fungi, mites and lice.

Feather care is crucial to the bird. After all, feathers help to insulate it from the cold, waterproof it from the rain and ensure trouble-free flight.

When not foraging or indulging in other activities, a bird can be seen perching on a branch and carefully preening its feathers. The wing is stretched out and the head moves towards it to carefully preen the feathers. The tail is raised and the head turned back to attend to the tail feathers.














In areas where the bird cannot reach with its bill, like the top of the head and neck, it uses its foot to scratch. Sometimes it may indulge in mutual grooming, also known as allopreening. Besides having the hard-to-reach parts preened, allopreening strengthens bonding between the birds. It is commonly seen between sibling birds.

Other methods of feather maintenance includes anting, sunbathing and dust bathing.

Image of White-crested Laughingthrush (Garrulax leucolophus) (top) by Johnny Wee; those of Olive-backed Sunbird (Nectarinia jugularis) (bottom) by YC.

Wednesday, June 14, 2006

Beginning of a new breeding season...

Beginning of a new breeding season...

February must be the beginning of a new breeding season. In and around my garden, I can see birds busy collecting nesting materials.

The Asian Glossy Starlings (Aplonis panayensis) are arriving at the ceram palm to harvest palm frond fibres. They perch along the midrib of a leaflet, moving sideways towards the tip, pecking on the side of the leaflet to loosen a piece of fibre. The tips of these leaflets are usually frayed by the wind and pieces of fibres are exposed towards the tips. Just as suddenly as they arrive, these starlings suddenly fly off to their nests’ sites. After some time they return and make further collections.

The Javan Mynas (Acridotheres javanicus) (as well as the starlings), on the other hand, are collecting pieces of fresh golden penda (Xanthostemon chrysanthus) leaves. They peck the young leaves to break pieces and fly off with them. I am not sure what their nests look like but I must imagine that they are lined with fresh leaf pieces that eventually dry up. Our bird specialist, R. Subaraj, says that it is advantageous to harvest fresh leaves. Besides being pliable, the pieces last longer than if the bird starts with dead brown leaves. Sounds logical to me! Besides harvesting leaf pieces, they are picking palm fibres off the ground.

The Pink-necked Green Pigeons (Treron vernans) are back at the ceram palms, making courtship sounds and behaviour. A few males are collecting twigs from the mempat trees (Cratoxylum formosum) along the road, flying in and out as they start to build their nests.

The Yellow-vented Bulbuls (Pycnonotus goiavier) are similarly harvesting nesting materials. They have been at my Alexandra palm (Archontophoenix alexandrae), collecting old stems of the dragon scale fern (Pyrrosia piloselloised) to build their nest.

Then the Olive-backed Sunbirds (Nectarinia jugularis) are actively collecting spider’s web. They hover around where these webs are and peck off pieces to bring to their nest.

The above observations are only in my suburban garden. I am sure all over the island other species of birds are busy collecting nesting materials to construct their nests.

Yes, a new breeding season is beginning!

Our bird specialist, R. Subaraj has this to say: "Many bird species do indeed start breeding from Feb/Mar, though some start as early as Dec/Jan and others as late as Apr/May. Those starting in Feb/Mar may have two broods with the second season commencing around May/June, right after the first batch fledges. The breeding season seems to follow the migration timing and birds seem to choose the period of less competition from migrants as well as less predation from migrant hawks - Japanese Sparrowhawk (Accipiter gularis) and Chinese Goshawk (A. soloensis) are common between Oct-Feb and specialise on small birds.


Input by R. Subaraj and YC, images by YC

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Monday, June 12, 2006

Life around a rotting tree trunk 4: Dollarbirds and parakeet

Life around a rotting tree trunk 4: Dollarbirds and parakeet

Dollarbirds can be very aggressive indeed, especially when their nests are being raided by other birds. This exciting drama was captured on 'film' by Chan Yoke Meng at the patch of secondary growth at Eng Neo recently.

Meng was there on 9th April 2006 waiting for the hornbills to appear when he suddenly saw a Long-tailed Parakeet (Psittacula longicauda) entering the nesting hole of the Dollarbirds (Eurystomus orientalis). This pair of Dollarbirds had taken over the cavity from a pair of Long-tailed Parakeets earlier.

Th parakeet's sudden entry into the nest caused panic among the pair of Dollarbirds that was around the dead tree. The latter were circling around and screeching when suddenly one flew straight into the nest. The parakeet was already inside the cavity but the Dollarbird pushed itself in, got hold of the former’s beak and literally dragged the parakeet out of the nest. The Dollarbird succeeded in expelling the intruder from the nest. Peace returned to the area.

For the next hour or so one of the Dollarbirds remained in the nest, its body blocking the entrance and one of its legs firmly placed on the rim. It was in defensive mode, ready to fly out and confront the parakeet should it attempt to make a further attack. The other Dollarbird stationed itself at the top of the trunk
Whether the parakeet did any damage to the occupants, either the eggs if the birds were still incubating or the nestlings if any had hatched, could not be ascertained. But the Dollarbirds were still seen flying regularly into the nest a week after, usually one entering the nest for some minutes while the other stood guard at the top of the rotting trunk.

Input and images by Chan Yoke Meng.

For R. Subaraj's comments, see here.

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Saturday, June 10, 2006

Forensic birding 4: Seeds

Forensic birding 4: Seeds

Most mornings during the months of February and March 2006, I found seeds scattered along my driveway. They appeared in ones and twos, sometimes more. The ones I recognised were MacArthur (Ptychosperma macarthurii) (1, left) and Alexandra (Archontophoenix alexandrae) (2, left) palms seeds.

The seeds were always devoid of the outer fleshy covering. Because of their condition, they could not have come from the rear end of any birds. They must have been regurgitated. But by what species of bird?

I have evidence that the Asian Glossy Starling (Aplonis panayensis) swallows Alexandra palm fruits whole, and regurgitates the seeds soon after. Yellow-vented Bulbul (Pycnonotus goiavier) pecks on these fruits but swallows whole fruits of MacArthur palm. But I have yet to witness any regurgitating of the seeds by the bulbul.

The bird or birds responsible for scattering these seeds on my driveway could be either of these two birds. They would be perching on the frond backs of the two tall Ceram palms (Rhopaloblaste ceramica) by the driveway. The starlings regularly visit the palm to shelter from the heat of the day among the old inflorescence branches and old spathes that cluster around the base of the crown that have yet to be dislodged. They also come to feast on the ripe fruits. The bulbuls are fewer.

In March my Alexandra palms were fruiting. The starlings were feasting on the ripe fruits and they were also resting in the Ceram palms. During this period I found more of these palm seeds as well as those of MacArthur palm.

I have also found many other types of seeds that were probably regurgitated by birds. I have yet to ID them as I need to germinate then and have the seedlings identified. When I know their ID I will make a posting on this blog. In the meantime we just have to wait and see…

Input and images by YC.

Thursday, June 08, 2006

What do hornbills eat?

What do hornbills eat?

Most Asian hornbills are omnivorous, taking both plant and animal foods. However, there is a preference for fruits and small animals. And figs are the favourite, although there are reports of them feeding on rambutans (Nephelium lappaceum) as well as a great array of forest fruits.

Animals are taken by hornbills, especially during the breeding season. These include scorpions, lizards, geckos, skinks, earthworms, frogs, caterpillars, beetles, butterflies, cicadas, grasshoppers…

Great Hornbills (Buceros bicronis) feed primarily on fruits, especially figs. But they also hunt actively for small animals like snakes, lizards, bird nestlings and eggs, beetles and insects.

Figs are consumed at a rate of about 200 per sitting. The figs are delicately picked with the tips of their mandibles. But not larger figs like those of Roxburg’s fig (Ficus auriculata) (above). These are not swallowed whole but rather eaten piece by piece. Tan Teo Seng, who has a fruit farm in Kota Tinggi, Johor, reports that flocks of Oriental Pied Hornbills (Anthracoceros albirostris) invade these trees whenever they are covered with figs.

When hornbills swallow fruits with large seeds, these seeds are regurgitated up to an hour later undamaged. Sometimes seeds are also passed through the digestive tract, which is the case with figs as the seeds are extremely small. As such, hornbills are good seed dispersers of forest plants.

Thanks to Tan Teo Seng for his input. Image of Oriental Pied Hornbill by HK Tang and of Roxburg's fig by YC.

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Tuesday, June 06, 2006

Black-shouldered Kite and the House Crow

Black-shouldered Kite and the House Crow

An earlier posting gave an account of the House Crows (Corvus splendens) raiding the nest of the Black-shouldered Kite (Elanus caeruleus) and ending with the crows flying off with anything edible found in the kite’s nest. This account is about the revenge of the kite. The accompanying dramatic images have been captured by photographers Meng and Melinda Chan in Lim Chu Kang some months ago. They have agreed to this post so that more can share their experience.

House Crows are bold scavengers, never letting an opportunity of a free meal go. They would steal any food from anywhere if they can get away with it. This is a story of a crow trying to steal from a juvenile Black-shouldered Kite that was feasting on a rat.There were three juvenile Black-shouldered Kites perching on a tree, one of which had a rat firmly clutched in its left foot. A House Crow spotted an opportunity of a free meal and flew down to perch some distance from the kite. Interrupted from its meal, the kite looked up and suspiciously eyed the crow. The crow moved closer to a nearer branch, eying intensely the rat tightly clutched within the talons of the kite. The crow must have violated the comfort zone of the kite. The kite suddenly lunged at the crow, taking the latter by surprise. The crow retreated and flew off, leaving the kite to continue eating its meal. The last image shows the kite eating the rat with its right wing outstretched, shielding its food from his two sibling as well as the crow, which was still around. Text and images courtesy of Meng and Melinda Chan.

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Sunday, June 04, 2006

Crimson Sunbirds and the noni tree

Crimson Sunbirds and the noni tree

The male Crimson Sunbirds (Aethopyga siparaja) are fascinating to watch as they flit from branch to branch or leaf to leaf in my noni or mengkudu (Morinda cirtifolia) tree. They announce their presence by their high-pitch ‘cheet-cheet-cheet’ and grab your attention by their bright crimson head and metallic blue forehead.

Some days they visit the tree mornings and evenings. Other days they also come during the afternoons. Mostly, they come to drink the nectar from the many white flowers.

However, during a slight drizzle or just after the rain, these birds visit for another purpose. The leaves are then covered with droplets of water and the birds come and dance around, rubbing their bodies against them in play. The large leaves apparently see to it that the birds do not get drenched as they provide some protection from the rain.

Just as suddenly as they appear, these birds suddenly disappear, with their feathers covered with droplets of water.

These Crimson Sunbirds regularly eat the fruits of the mistletoe Dendrophthoe pentandra that grow on the branches of the nearby mempat trees. These birds must have left some seeds in the noni tree when foraging for nectar. An old detached leaf was found on the ground with a mistletoe seedling growing from the stalk. Obviously this was a wrong location for leaves do not remain long on the tree.

Our young naturalist Serin Subaraj wrote about sunbirds bathing on leaves covered with water droplets after each watering in the garden. Well, these Crimson Sunbirds similarly are attracted to the noni tree whenever my volunteer gardener Eileen, waters the foliage instead of the ground below.

Text and images by YC.

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Friday, June 02, 2006

Life around a rotting tree trunk 3: The coming of the Dollarbirds

Life around a rotting tree trunk 3: The coming of the Dollarbirds

The pair of Collared Kingfishers (Todiramphus chloris) nesting in a cavity found at the central point of a rotting tree trunk in a small piece of secondary growth at Eng Neo had no problems of accessibility to their nest most of March 2006. By early April a pair of Dollarbirds (Eurystomus orientalis) took over the nest at the top cavity from the pair of Long-tailed Parakeets (Psittacula longicauda). The nesting parakeets gave the kingfishers no problem. Not so the Dollarbirds.

The pair of Dollarbirds regularly patrolled the area around the tree trunk or simply perched at the top, defending their territory jealously. Whenever a kingfisher approached its nest at the central cavity, one or the other of the Dollarbirds would fly out to meet it halfway. There would always be a confrontation and the kingfisher would veer off, not able to enter the nest. Only when the Dollarbirds were absent could the kingfishers fly into their nest to feed their young.

Allan Teo, an avid photographer, captured the dramatic moments when both birds confronted each other. His two crucial images show first, the Dollarbird flying off its perch when the kingfisher flew towards its nest. At about 2.5 metres away, the former lunged an attack.




















In his very own words: “The Dollarbird defended its ground aggressively. Not to be put off, the Collared Kingfisher also stood it ground. No contact was made between the birds as the 'fighting' took place. The kingfisher veered off the perimeter defence of the Dollarbird and both went apart peacefully after that. Note that the Dollarbird can 'freeze' in midair whilst the kingfisher cannot.

”The action took place in split seconds and the camera could capture the action. Photography provides another valuable insight into intelligent animal behaviour.”

I totally agree. Photography has an important role to play in the study of bird behaviour. That is why more and more birders are taking photography, including digiscoping and videoscoping.

Input by Allan Teo, images by YC (top two) and Allan (bottom two of Dollarbird attacking kingfisher).

Our bird specialist, R. Subaraj, has this to say: "This is intra-species bird behaviour at its best! The agression shown by nesting birds is quite interesting to observe. Yet, the general lack of nesting holes, especially for species not able to excavate cavities for themselves in living wood, can make for lots of fighting for nesting space. Likewise, woodpeckers and barbets, who are able to excavate their own nesting holes, are often displaced from them by other hole-nesters.

"The situation is further complicated by the active removal of dead branches and trunks, for fear that they would fall down and cause damage to property. The loss of rural areas in recent times, particularly coconut groves, has also removed many potential nesting sites for such birds. The "topless" coconut trunks are favourite nesting sites for Dollarbirds, parakeets and other hole-nesting species."

Thursday, June 01, 2006

Red-crowned Barbet feeding on a snail

Red-crowned Barbet feeding on a snail

Barbets are stout birds with a prominent bill and bright, colourful plumage. Another characteristic feature is the prominent nasal and rictal bristles. They nest and probably also roost in tree cavities, thus they are found in wooded areas with old trees.

On 3rd April 2006 Johnny Wee came across a Red-crowned Barbet (Megalaima rafflesii) eating a forest snail at the Upper Peirce Reservoir forest.

Now barbets are predominantly frugivorous. Their favourite fruit is fig but they also eat other fruits as well. Small fruits are swallowed whole and if they have large seeds, these are regurgitated. Larger fruits are pecked down to manageable pieces and chewed before swallowing. The brush-like tongue helps in breaking down or manipulating pieces of fruits. Some species also eat nectar from the flowers of Erythrina, Bombax and Butea.

But barbets are not exclusively frugivorous. They can be opportunistic feeders, seeking out insects, especially when there is a termite hatch. They also eat insects and other arthropods when available. During the nestling stage the young birds are fed with animal food immediately after they hatch out of the eggs.

There are records of Lineated Barbet (Megalaima lineata) eating bird’s egg and nestling, as well as catching lizards and frogs.

A Red-throated Barbet (Megalaima mystacophanos) was reported by Medway & Wells in 1976 feeding on a snail in Ulu Gombak, Selangor, Malaysia. A male bird was seen passing a snail, after much beating against a branch, to a female, in an apparent courtship feeding.

Although the observation by Johnny is not new, it is probably a new record for Singapore. According to Leong Tzi Ming the snail looks like an Amphidromus sp.


Thanks to Johnny Wee for the observation and image, Wang Luan Keng for the lead to the reference and Leong Tzi Ming for the tentative ID.

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