The Black-thighed Falconet (Microhierax fringillarius), 15-17 cm in size and monotypic, can be found quite easily in Peninsular Malaysia. In early 2007, Ms Connie Khoo, a passionate birder and digiscoper, spent time in the heat of the day keeping watch as well as making detailed notes on the nesting cycle of this bird.

The nest or eyrie was about 10 meters above ground on the cliff face near Kek Lok Tong in Ipoh, Malaysia, an area famous for its limestone hills and caves. The image above gives you an idea of the type of limestone habitat where the nesting took place.

She noticed four adults looking after four chicks. The four chicks most probably came from one pair of adults while the other two adults were probably helpers. It is known that raptors can be sociable in that they come together to help each other during the breeding periods. This has also been observed in Silver-breasted Broadbill (Serilophus lunatus), seen in Bukit Tinggi during the last nesting season, where helpers got involved in nest building.

Copulation took 30 seconds to about 1 minute 12 seconds to complete. Observations in 2005 and 2006 recorded 1 minute 28 seconds, although it cannot be confirmed whether the same birds were involved.

On 5th April the female was possibly incubating her eggs, which can be from two to as many as five. The female stayed in the nest for long periods, occasionally appearing at the nest entrance for fresh air and to ease herself (above left). All this time the male would deliver prey for her to eat. And he would leave in about 10-30 seconds after delivering the food.

The incubation period was about 3-4 weeks and the chicks fledged in another 4-5 weeks. On 2nd May, the first chick was seen covered with white down feathers, and was probably about 7-10 days old. The image at the top (below the limestone cliff) shows a 15-18 days old chick at the entrance of the nest.

On 31st May a young juvenile was seen strengthening its jaw by yawning for about 50 minutes (right). When the male brought food, the juvenile finished it quickly and continued yawning for another 20 minutes. This yawning exercise was seen again on 2nd June and lasted 35 mintues.

The juveniles were fed dragonflies, butterflies (above right), beetles, spiders (above left), small birds like sunbird, tailorbird, munia (below right) and tree sparrow. Occasionally there would be a small lizard or a rat. However when the chicks were very young they were fed only dragonflies, beetles, moths, butterflies and spiders.

Occasionally, mynas and starlings would appear around the eyrie. Invariably the adults would fly back to chase away the intruders. On 7th May at 11.08 am, a tree sparrow appeared and perched just outside the nest. The female falconet suddenly emerged from the nest and caught the surprised sparrow (above left).

By 2nd June the juveniles must have grown quite a bit as one was observed catching a dragonfly by itself (below). However they still needed the parents to catch for them more substantial meals like birds and other small prey. During this period when the juveniles were actively exploring the surrounding areas, the adults were constantly keeping a watchful eye on them, to prevent them from becoming prey to other birds.

On 5th and 9th June when Connie again checked the eyrie, she could not see all the four juveniles. Only one or two adults were in the vicinity. The rest of the adults were possibly teaching the juveniles how to hunt. At 10.25 am she saw one female with one juvenile flying back to sit on the wire. Shortly after, the female left the juvenile and twice brought back a dragonfly each time for the same juvenile. The juvenile was then yawning a lot, possibly to continue strengthen its jaw.

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Imput by Connie Khoo and K C Tsang; images by Connie except that of the limestone outcrop by YC.

19th June 2007

Birds have been known to build their nests in close proximity to nests or hives of ants, bees and wasps. There is an advantage in such a relationship as the nesting birds are generally protected from predators, not so much by ants but more so by wasps.

A number of Baya Weaver (Ploceus philippinus) nests were recently seen high up the same tree where the lesser-banded hornets (Vespa affinia, Family Vespidae) have built their large nest (above). This nest, built from finely chewed fragments of wood mixed with saliva, has a typically papery appearance, thus it’s other name, paper wasp.

A social insect, the hornet has a distinct yellow banding on its first and second abdominal segments (left). It is the most aggressive of the three species of hornets found in Singapore. It will attack with the slightest provocation and its sting is painful. Unlike bees, hornets can sting repeatedly. The effect of the poison injected with the sting depends on the species and how sensitive the victim is to the poison. Response can be localised pain, swelling and redness. In more serious cases chest constriction, wheezing and vomiting may occur. Death can also result. Immediate medical attention is advisable.

Because of the poisonous nature of its sting and its inclination to attack at the slightest provocation, hornet gives perfect protection to the nesting weavers.

In a study in Ghana, it was shown that the Red-cheeked Cordonbleu (Uraeginthus bengalus) benefited by nesting near the wasp Ropalidia cincta. The chicks of these birds were twice as likely to fledge as those that nest in trees without wasps. Reduced predation was apparently a major reason for increased fledging success. There were four cases of nest predation on 122 Red-cheeked Cordonbleu nests associated with wasps, and 11 cases on 90 nests not associated with wasps.

Input by YC, images by Chan Yoke Meng, wasp identification by Prof Cheong Loong Fah.

Reference:
Beier, P. & Tungbani, A. I. (2006). Nesting with the wasp Ropalidia cincta increases nest success of Red-cheeked Cordonbleu (Uraeginthus bengalus) in Ghana. The Auk 123(4):1022-37.

Gopalakrishnakone, P. (ed.) (1990). A colour guide to dangerous animals. Singapore University Press.

In early May 2007 an Oriental Pied Hornbill (Anthracoceros albirostris) visited Johnny Wee’s garden to raid his guava tree (Psidium guajava). The visit came one afternoon, after a prolonged period of a few days of rain. He was alerted to the presence of the bird by its characteristic call. Peering out of his bedroom window, he was visibly excited to have this large bird paying him a private visit.

The bird was quietly pecking the ripe guava fruits and taking pieces from them. As soon as it had a piece of the fruit at the tip of its bill, it tipped its head back to allow the piece to fall into its throat (bottom). Apparently the fruits are too large and possibly too hard for the bird to swallow them whole, unlike with the larger figs.

We now have on record for Singapore of the Oriental Pied Hornbill eating guava fruits and the bird is obviously another dispersal agent.

The guava tree is not native to Singapore (above). It was introduced to this part of the world a very long time ago probably by the Portuguese explorers. This exotic plant has now become naturalised all over the tropics and subtropics, in some places even becoming a weed. And birds play a leading role in its spread.

Once there were plenty of these trees around, especially in our rural farm areas. Nowadays a few may still be growing in private gardens, parks and wastelands. The tree is sun-loving, meaning that seedlings sprout in open areas. It is also fast growing, fruiting within a year or so. It fruits profusely and many birds are attracted to the succulent fruits that are full of numerous, small, hard seeds. These seeds pass through the alimentary tract of the birds to be deposited some distance away. In other countries cattle, horses and even pigs help spread the seeds. And these seeds remain viable in the ground for long periods.

This is another example of an exotic plant that has become useful to our birds.

Input and images by Johnny Wee.

Goh Si Guim tells the sad story of a pair of Olive-backed Sunbird (Cinnyris jugularis) that nested along the third floor balcony of a private house. The nest was built suspended from a money plant (Epipremnum pinnatum Aureum) growing in a pot that sits among other potted plants (left). To the untrained eyes the elongated nest looks like a mass of dead leaves stuck together with cobwebs. And that was what the residents thought. Until there was frenzy of feeding activities when the chicks hatched…

“Apparently nobody paid any attention to this mass of dried plant matters, never even realizing that it was a sunbird’s nest. It was only when the eggs hatched and the feeding frenzy started that the residents began to take notice of the nest. And of course when the plants were watered, there were angry confrontations with the parent birds.

“Apparently the original nesting began sometime in mid-April 2007. And the chicks fledged successfully.

“In the third week of May there was a frenzy of nest building when the birds got down to raising their second brood along the same balcony. They were actually refurbishing the old nest, adding new materials… By early June the chirping of the chicks were heard.

“On Monday morning, 11th June, disaster struck:

“In the words of the homeowner: ‘As I was having my breakfast, my thoughts were interrupted by incessant squeaks and tweets. Looking out into my balcony, I noticed the papa sunbird nudging his chick. The chick seemed to have fallen onto the floor and the papa sunbird was trying to move it back into the nest, a near impossible task as the chick was as big as its papa (right bottom).

“’As I went out to investigate, I noticed another chick a few feet away. The nest had given way! (right top). I then saw the mama bird nearby. Both the mama and papa birds were bringing food to their chicks so that they would not get hungry.’

“When the homeowner’s father arrived 15 minutes later, one of the birds had disappeared! ‘Father came and immediately began his rescue mission. Unfortunately, one chick had disappeared.’ It remained unknown whether it fell off the balcony or was snatched by a predatory bird.

“In their haste to start the next family, the maintenance or re-sprucing of the original nest may not have been up to standard. The wear and tear may have not allowed it to sustain the weight of the growing chicks, or it got too crowded and the structure gave way.

“The remnant of the nest was cut and placed in a plastic dessert bowl. The remaining chick was placed with this makeshift nest, which is then placed partially hidden among the potted plants (above left). It was hoped that the chick would feel secure and familiar near the nest and that the parents would recognise the chick and continue to feed it.

“The homeowner continued: ‘By night fall, the chick had crawled up the nest to sleep (above right). We shall have to wait to see if the papa and mama bird will come back to the chick.’

“However, the next morning, it was noticed that the chick was silent and was not responding to the calls of the parents (left). It may have been disorientated from being out of the protective comfort of the nest or instinctively chose to remain silent to avoid detection or predation by marauding crows. As the chick did not respond to the parents’ calls, they did not proceed to feed it.

“This did not augur well.

“However, as the homeowner would be at work the whole day, hopefully there would be ample time for the family to get re-acquainted with each other.

“Alas, my premonition was accurate. The chick did not survive the day. It was found lying on its side, motionless, by the homeowner on Tuesday night. The papa and mama birds were on a nearby tree to mourn their loss (right).”

Input and images provided by Goh Si Guim.

For the last six months, Johnny Wee had been noticing a pair of Spotted Dove (Streptopelia chinensis) at around noon, especially when the weather was hot. They would arrive to perch along the metal bar that formed part of the boundary fence of his house (left). There, the birds rested, shaded from the hot sun. They stayed for about half an hour each time, silently doing their own comfort activities – not a sound was heard while they were there. There were no flapping of wings, no bobbing of heads and no sign of copulation.

All the birds did was preen. Sitting slightly apart and with feathers fluffed, each bird would indulge in self-preening. Every now and then they would sit close and allopreen. One bird (male? female?) would stretch out and preen the head of its partner, then stretch further across the neck to reach the other side of the head and neck. It is noted that the preening bird often had its eyes closed or partially closed. The bird that was preened had its eyes fully open (below). [Should it not be the other way round?]

Is this part of the courtship ritual of the Spotted Dove? Or is it a normal bonding activity between a pair of doves? Normally, the onset of breeding would see the birds prospecting for suitable nesting sites before actual nest building takes place. And courtship displays may involved one or more of the following: strutting with accompanying wings-tail movements, feeding and aerial displays. The sad fact is that we are mostly ignorant of what actually happened during this period – I may be wrong here and by all means please prove me wrong. And this bird is relatively common and easy to observe in urban areas. On top of it the bird is easy to recognise from the trademark patch of black and white chequer on the sides of the neck.

Input and images by Johnny Wee.