Albizia (Paraserianthes falcataria) trees have been in the local news since the recent spate of tree falls that resulted in a number of people being injured and even killed - locally as well as in neighbouring Malaysia. As a result of the bad publicity in the media, various government agencies have been quick to remove these large and graceful trees from wastelands all over Singapore.

The tree is native to countries in east Malesia to the Solomons. It was introduced and grown in the Singapore Botanic Gardens in the 1870s. It has been flourishing in wastelands ever since. The nitrogen-fixing bacteria that are found growing in the roots help the trees to proliferate in these nutrient-poor soils.

The tree is fast-growing, capable of attaining 20 metres in three years or more. It bears compound leaves, bearing small white flowers that develop into pods. It grows tall, with wide-spreading branches and as such was once commonly used as a shade tree in coffee and tea plantings. Because growth is rapid, the wood is soft and earlier used in the manufacturing of matches and packing boards.

Since the start of Singapore’s Garden City Campaign in the 1950s, albizia has never been used as a roadside tree. In fact, any found growing near roads were removed. The shedding of branches during tropical storms and the aggressive roots that grow near the soil surface make it dangerous for such use.

Albizia trees are now confined to wastelands where they proliferate, helping to reduce soil erosion and providing refuge to a wide variety of wildlife (above). Yes, there is always the possibility of branches falling, but away from human habitation and in areas where few, if ever, any people venture, they should not pose any threat to life and limb. Their presence thus should be tolerated. To chop down these magnificent trees and replace them with other species is a waste of resources.

According to an article by Dr Ho Hwa Chew, these trees are rich in wildlife. There are at least 40 resident and migratory bird species that make use of the trees, either seeking food, nesting materials or a place to build their nests. Prominent among which are the Common Flameback (Dinopium javanense) (right), Long-tailed Parakeet (Psittacula longicauda), Dollarbird (Eurystomus orientalis) and Hill Myna (Gracula religiosa). The White-bellied Sea Eagle (Haliaeetus leucogaster), Changeable Hawk Eagle (Spizaetus cirrhatus) and Grey-headed Fish Eagle (Ichthyophaga ichthyaetus) make use of these trees to nest.

At the same time, natural cavities that develop in these old trees provide potential nesting holes for hornbills, as seen in an old and magnificent tree at Eng Neo. Although the pair of hornbills, Great (Buceros bicronis) and Rhinoceros (Buceros rhinoceros), are both escapees, not to mention that they are also both females, the fact that they were prospecting for a nesting cavity points to the value of albizia to the bird life of our Garden City, if not a City in a Garden - see 1 and 2 for details.

Also, an old, rotting albizia trunk nearby, that was never a danger to anyone, was the centre of a busy and exciting community of birds that fought for the privilege of making use of the few cavities for nesting, posted earlier: 1, 2, 3, 4 and 5.

So, where these large and beautiful trees pose no danger to anyone, can the authorities please leave them alone?

This post has been commissioned by Yong Ding Li, who is concerned that these trees would continue to be indiscriminately removed. Images by YC.

An image of the Asian Koel (Eudynamys scolopacea) eating the fruits of Pipturus argenteus (Family Urticaceae) was recently submitted by bird photographer Chan Yoke Meng (left top).

This is a shrub with unisexual flowers and small, black fruits in a white foamy and fleshy receptacle (left bottom). The entry in Keng (1990) states: “A fairly recent introduced weed of the Pacific Isls., found in waste places in city areas.”

Unlike most cuckoos that feed on insects, this koel feeds largely on fruits. This is another example of birds adapting to exotic plants in their search for food.

Input and image of koel by Meng and Melinda Chan; Angie Ng helped in identifying the plant and KF Yap supplied the images of the plant and reported that he has once seen an Asian Koel eating a ripe papaya (Carica papaya) fruit.

Reference:
Keng, H. (1990). The concise flora of Singapore. Singapore University Press.
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There is a bodh-tree (Ficus religiosa) at the entrance of the Chinese Garden in Jurong and it is figging. And a figging tree invariably attracts flocks of birds – not just birds of a feather but of different feathers. In other words, there would always be a mix of species that come for the feast. The noise these birds generate is enough to attract hordes of birders and photographers.

And it was so with this particular fig tree on the day after Christmas this year. KC Tsang was there and sent in the image above of the Asian Paradise-flycatcher (Terpsiphone paradisi) perching next to the Coppersmith Barbet (Megalaima haemacephala). KC also filed this report:

“The fig tree near the entrance of the Chinese Garden is fully laden with fruits, not all are ripe, but this has been a great attraction for many kinds of birds, from fruit eating ones to insectivorous birds. The types of birds observed visiting the tree are, fruit eaters: Asian Glossy Starlings (Aplonis panayensis), Asian Koels (Eudynamys scolopacea), Coppersmith Barbets, Yellow-vented Bulbuls (Pycnonotus goiavier), mynas, and Pink-necked Green Pigeons (Treron vernans).

“The insectivorous birds comprise Asian Paradise-flycatchers, Mugimaki Flycatchers (Ficedula mugimaki), Asian Brown Flycatchers (Muscicapa dauurica), Dark-sided Flycatchers (Muscicapa sibirica) and Arctic Warblers (Phylloscopus borealis).

“The Asian Glossy Starlings would come in waves, taking over the whole tree, but they are observed to be not aggressive to other birds, while the Asian Koels would intimidate other birds and the Asian Paradise Flycatcher would chase the Mugimaki around the tree.

“Coppersmith Barbets are seen to be left alone to do their own things, like eating the fruits quietly.

“All these activities were observed on 26/12/2007, and it will last only as long as there are fruits to be had on the tree, which I believe will last for only a few more days.”

If there are any birders or photographers who are still not aware of this figging tree, hurry to the Chinese Garden before the feast is over.

Image by KC Tsang.

On the evening of 30th October 2007, I was alerted to the call of a Red-whiskered Bulbul (Pycnonotus jocosus) that regularly visit my garden. It continuously made a high pitch wit-ti-waet. Normally, they would perch on the fronds of my two tall ceram palms (Rhopaloblaste ceramica). This time the call came from another location. It was from my starfruit tree (Averrhoa carambola ) (above). Trying hard to locate it, I went under the tree and imitated the call until I located its position. The bird returned my call and continued perching where it was, even when it noticed me below, not more than a metre-and-a-half away.

About half an hour later the call was again heard. This time there was at least a pair of the Red-whiskered Bulbuls. Together with this pair were half a dozen or so Yellow-vented Bulbuls (Pycnonotus goiavier).

The birds were busy moving rapidly from one branch of the tree to another, pecking at something that I thought were ants. Looking at the birds through a pair of binoculars, I soon found out that they were actually plucking flowers and flower buds off the branches and swallowing them (above: Red-whiskered left, Yellow-vented right).

All this time the Yellow-vented were not making any calls and only the flapping of their wings was heard as they moved around the crown of the tree.

This was the first time I have seen either of the bulbuls in the tree, not to mention seeing them eating the flowers and the buds.

The next afternoon I again heard the call of the Red-whiskered. This time it was alone. Again I imitated its call until I located where it was. It was perching by a bunch of flowers and actively picking and swallowing flower buds. At times it moved along the branch, pecking around its feet, no doubt picking ants. Soon, its call attracted another bird, but I was not able to see whether it was a Yellow-vented or another Red-whiskered.

The Common Tailorbird (Orthotomus sutorius) can often be seen gleaning insects. And the Tanimbar Corellas (Cacatua goffini) visit the tree when it bears young fruits.

Input and images by YC.

An image by Melinda Chan shows a male Brown-throated Sunbird (Anthreptes malacensis) robbing nectar from a hibiscus flower by probing his bill through the base of the flower (left).

Now why did the bird do that?

The natural pollinator of hibiscus has been reported to be the hummingbird. The sunbird is not adapted for hibiscus pollination, so to harvest the nectar in the flower, it has resorted to the unconventional method of probing the base of the flower. This is referred to as robbing, as by doing so the bird is not doing the flower a favour, i.e. assisting in its pollination.

Hibiscus or China rose (Hibiscus rosa-sinensis) is native to continental Asia, probably China. The species has been in cultivation in various forms for centuries and the species itself has never been found in the wild. In Singapore, the plant never produces any fruit or seeds.