Nature Notes

September 2009

BY ANGELA HIJJAS

Shorea acuminata, meranti rambai daun, is in the red meranti group of Shoreas. It is a tree of the southern half of the peninsula, most common in Negeri Sembilan and Melaka. It prefers low lying well-drained land and is often the most abundant meranti in the forest. Although greatly reduced by forest conversion, this species is not currently at risk. This species was planted at Rimbun Dahan about 12 years ago and is fruiting for the first time, but very sparsely.

See other dipterocarps in the garden at Rimbun Dahan.

by Angela Hijjas

We already have two species of primates at Rimbun Dahan, without counting humans — the common, gregarious and inquisitive long-tailed macaques, Macaca fascicularis, and the shy and retiring langurs who frequent the treetops in smaller family groups.

We have had occasional sightings recently of a pig-tailed macaque, Macaca nemestrina, or beruk in Malay, a very large monkey that has been traditionally used to pluck coconuts and throw them down to their handlers on the ground. You could once see them being taken from grove to grove on the owner’s bicycle, sitting on the handlebars, holding on and staring grimly ahead.

E. J. H. Corner, the famous botanist of the ’40s and ’50s, trained them to pluck samples from trees in the forests of Johor, but apparently they had to be trained only in Kelantanese dialect, as that was all they understood! Eventually one of Corner’s beruk attacked him, landing him in hospital for several months, but probably saved him from being killed by the occupying Japanese during the World War II. Beruk are known to be aggressive; Corner himself noted that one of his specimens would, if allowed, “savage small children.” Our dogs at Rimbun Dahan are taking care to remain deliberately aloof.

by Angela Hijjas

No sooner did the pig tail macaque make an appearance than a real one pig came along — a baby wild boar, Sus scrofa, separated from its mother. The dogs cornered it apparently but because it bites they didn’t want to know much more about it. Sham, our handyman, heard the ruckus and found it, but it tried to bite him too!  Bad photos because I needed a flash, and it was wriggling a lot…

We have had occasional instances of wild boars at Rimbun Dahan, although these are fewer now that we have fixed a few holes in the fence. They come from the surrounding abandoned rubber estates, where they are hunted by weekend warriors for food. Wild boar piglets are striped, whereas adults are not — this is thought to help them stay camouflaged. Usually wild boar sows with piglets are particularly defensive of their young, and can inflict ferocious wounds although, unlike the male boars, they have no tusks.

by Angela Hijjas

May is nesting season, and we have sporadically heard and seen the Blue-winged Pittas that successfully bred two years ago in Rimbun Dahan. According to Jesmi the gardener, there are at least four individuals that call to each other from the depths of the garden. We hope to see another breeding success this year, so the area they favour for nesting (pictured left) has now been put off limits for grass cutting and pedestrians, although restricting dogs is a bit hard.

Meanwhile, among the native trees in the garden, the Firmiana malayana, mata lembu (below left), and the Kayea grandis (below middle) are flowering, and a very young Baccaurea lanceolata has a few fruits (below right).

No new snakes this month, although the Copperhead Ratsnake that caused such a stir a few months ago was sighted again near the studios, and I almost trod on one while walking the dogs up near the front gate! It reared up and demonstrated its characteristic vertical inflation that makes some people mistake it for a cobra. We have laid out the sulphur powder around the houses so people can sleep easy!

by Angela Hijjas

The only good Acacia…

… is a dead Acacia? Not this time…. In the middle of a traffic interchange on the Guthrie Corridor just near Rimbun Dahan, a solitary Acacia is hosting about eight Baya Weaver nests (Ploceus philippinus). In a completely open space, surrounded by what Guthrie considers landscaping (a sparse sprinkling of non-indigenous palms) is one Acacia draped and decorated with these ingenious nests.

On showing it to my grandchildren, I speculated why they had chosen this site rather than elsewhere: it’s out in the open and predators are readily seen, there’s safety in numbers, they are surrounded by open land where grasses can grow, and that’s what they feed upon. According to Allen Jeyarajasingam they frequently nest in association with nesting red ants and hornets, and the characteristic nest is a neatly woven flask shaped structure with a long downward tubular entrance, suspended from branches. We were too far to see the birds, and it was raining, hence the bad photo quality.

Rather than cropping this photo, and in view of our coming exhibition entitled Tanah Air, I let it stand as a record of our common landscape: oil palms forever in the background (it used to be forest), cleared and cut land where nothing can grow except for the admirable lalang and Acacia, an invasive species from Australia, and highways. Welcome to the new Malaysia.

by Angela Hijjas

A small group of Oriental Pied Hornbills (Anthracoceros albirostris convexus) has recently been seen around Rimbun Dahan. Like all hornbills, they have large bills topped with a hollow casque. This species is resident up to 150m, where it frequents forests, the forest edge, plantations and beach scrub. Although it feeds mainly on insects and other small vertebrates, it gathers in groups to feed in fruiting trees, as it did at Rimbun Dahan to feed on the fruits of Kelompang jari (Sterculia foetida).

Oriental Pied Hornbills are a noisy species, whose flight consists of rapid flaps followed by short glides. It is also remarkably tame — large groups can often be observed by vacationers gathering in beach-side trees on Pulau Pangkor.

In other bird news, Rimbun Dahan usually hosts a group of Ashy Minivets (Pericrocotus divaricatus) during the northern winter. The first two arrived on 3rd November 08, and more the next day. I have been observing them easing because the tree they favour was struck by lightning a few months previously, and has little vegetation. Fortunately there are three other trees close by of the same species, Terminalia bellirica, so the group of winter migrants had alternatives.

On the morning of 29th January, I saw an unusually large number, at least 25, in the same tree, with others flitting around and feeding on insects in the other trees. Then a second flock of possibly 40 birds (from the corner of my eye, I initially I took them to be mynas) flew past. Most of those in my tree took off and followed them, heading northwest. I suspect I witnessed the departure for the north – what a moment!

Our snake of the month is the Copperhead Ratsnake (Elaphe radiata Boie 1827), otherwise known as the Radiated Ratsnake. A fine specimen of this large non-venomous snake, over a meter long, was found this week in one of the artists’ studios.

Copperhead Ratsnake

According to Klaus Dieter-Schulz, who has published a monograph on the Elaphe genus, many snakes of this type are associated with water and swim very well, which has been confirmed with findings of the Copperhead Ratsnake far out to sea. It is thought that this helps them colonise offshore islands, and the snake is well distributed across Asia. Other typical ratsnake habitats include fallow land and scrub edges, interspersed with rubble and larger rocks, like abandoned quarries and refuse disposal sites. Many species of the genus also favour man-made environments, where they prey on newborn and subadult rodents. The Copperhead is sometimes encountered in piles of coconut shells, leading to its local name in Thailand of ‘Coconut Snake’.

When agitated the Copperhead Ratsnake assumes an interesting defence mechanism. It inflates the front half of its body, not width-wise like the cobra, but in height, meanwhile rearing up in an s-shape, in order to appear much bigger than it really is. “They literally dive towards the apparent aggressor with their mouth agape,” Dieter-Schulz writes, “The inflation of the neck causes the often differently coloured interstitial skin to become visible between the scales and the snake immediately assumes a different appearance.” However, if this attack is ineffective, the snake will also play dead, laying limp and motionless on the ground for some time.

Reference:
A monograph of the colubrid snakes of the genus Elaphe Fitzinger, by Klaus-Dieter Schulz, André Entzeroth. Published by Koeltz Sceintific Books, 1996.

November has been wet. Last night we had 35 mm of rain in an hour, and over the month a total of 437 mm, and still one day to go. Since we started recording rainfall in 2005, the wettest month ever was in November 2006 with 446 mm, and November 2008 may yet be more. A pity we can’t export to Australia…

A snake was found this morning on the road, apparently washed out of a tree and drowned in the deluge (picture below). It has been identified as a White-Spotted Slug Snake, Pareas margaritophorus, another new addition to the snake population at Rimbun Dahan. Lauren Black, whose room is in the guest house, had a tiny Paradise Tree Snake, Chrysopelea paradisi, on her balcony the other day, poking its head up through the floor slats (see images at right).

The population of macaques is thriving, but causing some damage to new plantings, although like the birds they feasted on buah salam, Eugenia pseudosubtilis (see image below left) . The newly planted Dipterocarpus crinitus, keruing mempalas, have had to be caged as the monkeys constantly pull off the new pink shoots thinking it is something to eat. Other Dipterocarps, like the Shorea gratissima, left, are establishing well. A new addition to the Dipterocarp collection is Shorea henryana, pictured at right.

It has been hard to find any colour in the garden with the constant rain, but the flowering ginger Hedychium coronarium (below right) is fruiting, and the Ixora schortechinii (below middle) is flowering; one must search the whole 14 acres for these small flashes of colour.

The birds, though, make up for this. The birding has been excellent this last month, made even better with the perch provided by a dead tree in front of the house. ‘Lifers’ in the last week were a Ruddy Kingfisher, Halcyon coromanda, and a Red-bearded Bee-eater, Nyctyornis amictus (right) and there was much excitement among the staff when four Oriental Pied-Hornbills, Anthracoceros albirostris, (left) perched on said dead tree for a few minutes.

BY ANGELA HIJJAS

The main objective in the planting programme at Rimbun Dahan is to develop the highest canopy possible, not always easy when trees tend to branch out as soon as they reach clear light. To encourage monopodial structure for as long as possible, we prune side branches and force the trees up by dense planting. Inevitably this has made them the tallest structures in the neighbourhood, apart from the DiGi tower on an adjacent block, and they are vulnerable to lightening. Two trees were lost on different occasions, a durian on the right-hand side and a Sterculia (fortunately not an indigenous species). We lose four or five trees a year, but then we have an open space where we can plant something else, in a ready-made ‘tube’ for rapid vertical growth.

The notes on Shorea sumatrana last month generated an interesting response on its rapid growth, spurring me on to measure more of Rimbun Dahan’s dipterocarps, although not all of them have a definite planting date. The following species have been measured this month, and the dates of planting noted where they are known. Measurements are in inches GBH, or girth at breast height.

1992, Shorea materialis, balau pasir, 10 saplings were planted in a sandy area of the garden and now measure between 18″ and 58″. There is no apparent reason why some have done better than others, but it seems where there is under planting and the trees are perhaps less disturbed they do better, but this is not always the case… the biggest of them all is out in the open.

Sizes of the ten trees are: 18″, 20″, 30″, 38″, 43.5″, 44″, 46″, 46″, 50.5″ and 58.5″.

A Terminalia foetida planted in the same vicinity at the same time measures 55″.

Three Hopea nutans, also planted at that time, or earlier, measure 30″, 21″ and 25″. Another four planted a few years later, measure 17″, 17″, 17″ and 15.5″. Planting dates are uncertain.

Beside the dance studio there are three Dipterocarpus dyeri trees, planting dates unknown, and they now measure 46″, 51″ and 52.5″. There is one 44″ Hopea nutans in the same area.

Three Dipterocarpus baudii planted in 1990, now measure 34″, 36.5″ and 28″. The last fell over at some point and was tied up to other trees for support, so that must have affected growth.

The row of Hopea odorata planted along the front drive in 1990 vary in size, the biggest being a princely 68″, but the others vary leading me to think that some seedlings are less successful than others.

Five Shorea roxburghii were planted in 1996 and they now measure between 31″ and 50″ (31, 33, 38.5,48.5, 50).

The following are not dipterocarps, but have done well:

A row of ten jelutong, Dyera costulata, was planted in 1999, but only six survive. Their dimensions range between 24″ and 50″ (24, 37, 42, 44, 47, 50).

Five ipoh trees, Antiaris toxicaria, were planted in 1989, and they measure between 53″ and 85″ (53, 59, 62, 62, 85). The 59er was struck by lightening about 5 years ago but recovered.

Just when you thought we couldn’t have more pictures of snakes eating things — here’s another scaly individual, possibly a rat snake or a bronzeback, gorging on a lizard, right near our front door! Photos by resident artist Oceu Apristawijaya.

We are also raising a new clutch of chickens… just 15, hopefully for our own consumption, hopefully not for snake food.