Birding in Malaysia turns up Siamangs!

Although I had never studied primates professionally when I went to Malaysia in December 2007, I had been intrigued by primates since visiting the upper Amazon with my brother and mother in 2005. Then on the way to a meeting in Kuala Lumpur, I stopped along the way in Vietnam and Cambodia. There I saw quite a variety of primate species, including some of the rarest in the world: white-cheeked gibbons, yellow-cheeked gibbons, crested gibbons, grey-shanked and red-shanked duoc langurs and Delacour’s lutungs in Vietnam (see by previous blog about this) and long-tailed macaques in Cambodia. On arrival in Kuala Lumpur, I spent a day in the giant city park, where I saw another subspecies of long-tailed macaques. After my meeting in KL, I went up to Fraser’s Hill, a high mountain, internationally famous birding spot. Originally, it had been a “hill station” one of many built by the British, ostensibly to guard the realm; but really it functions as a cool retreat from the heat of their lowland tea plantations. Now it serves that function for Malaysians, and for the few international travellers that venture that far from the city lights.
That night, wandering trails around the edges of town, I saw white-thighed surlis (Presbytis siamensis, commonly called langurs, but that is a Hindi word better reserved for the genus Semnopithecus, the well known temple and city langurs of India and Sri Lanka; the Malay words surili and lutung are better English common names for the southeast Asian Presbytis and Trachypithecus species, respectively). They hung around and walked along the branches of trees as I strolled the street below, regarding me with as much curiosity as I regarded them.
The next morning it was pouring rain. I left the hotel early and chose a trail that skirted the side of a mountain, making a big loop back to the town. This is a primary tropical forest: giant trees cast a gloom over untold number of smaller trees, shrubs and vines with orchid flowers and bromeliads brightening the path. Right away, I began hearing a loud “whoop, whoop” call and knew it was a primate of some kind. The experience in Vietnam had alerted me to listen for gibbons, which mate in monogamous pairs and call in duets, the male and female having separate parts of the song. I walked along, looking for birds and trying to keep my notebook and bird book dry. Every so often a “bird wave”—a mixed feeding flock—would come through, when I would frantically try to identify each species, juggling books and binoculars until they passed, leaving me listening to the rain drip from the trees and off the brim of my hat. Each time the trail turned in toward creeks that carved canyons in the mountainside and overwhelmed even the bird songs with their laughter, I lost the “whoop, whoop” calls, but as I emerged from these indentations, there it would be that call again, and closer.
Suddenly, I heard another call, sounding loud and excited. It was like “Yeow! Yeow!” repeated many times. Another species of primate? Had the troop I had been listening to met a troop of another species? Were they fighting?
Then there was a third call: a loud, long, drawn-out “Yeaaaaaaaaaaa...”. What was going on? Where there three species of primates interacting agonistically? Were they defending territories, attacking each other for food, or what?
These sounds were now ahead of me and to the left, below the trail. I walked faster, in case they might be seen from the trail; there was no hope of bushwacking through the jungle.
But now the sounds, which continued in a seeming frenzy were moving back the way I had come, and coming up the hill. Possibly they might cross the trail and give me a glimpse!
I turned and started running back along the trail. The primate calls kept coming closer; we were converging.
I had been walking carefully, both to stay dry by avoiding shaking the shrubs that overhung the trail, and to avoid the leeches that wait on vegetation for mammalian prey to come blundering through. But now I threw caution away and ran, leaping logs and scrambling recklessly over the boulders of creeks that I had already crossed.
Suddenly, there they were! Not three species or two, but a troop of siamangs making three different calls.
Siamangs (Symphalangus syndactylus) are the largest of the gibbons and look like a chimpanzee with hugely long arms. They move by “brachiation,” swinging from branches by their arms instead of walking on their legs. They are strictly arboreal, staying in the trees and almost never coming to the ground; hence, they need mature tropical deciduous forest for their survival. Like humans, they are mainly monogamous and mate for life. Their populations are decreasing and now are restricted to the Malaysian Peninsula and the Indonesian island of Sumatra and are endangered (IUCN Red List of Endangered Species, 2008).
I quickly began recording their calls. There was a dominant pair, and they both were making the “whoop, whoop” with a gular (neck) sack that inflates. At intervals, the female would start making the “Yeow! Yeow!” in a series call that started slowly and increased in rapidity and loudness, reaching a crescendo. At the top of the crescendo, the male would chime in with his “Yeaaaaaaaaaaa...” call.
Later, when I emerged from the jungle onto the streets of the village of Fraser’s Hill, I was tired, wet, and happy. A German couple, out for a morning stroll, looked at me a little aghast. “What?” I asked. They pointed to my neck and face. I was covered with leeches. These evil, tiny, thread-like parasites are a centimetre long to begin with and so thin that they can go through the fabric of socks. Before sucking your blood, they secrete a painkiller and an anti-coagulant into the bite so that you don’t feel a thing. When you pull them off, the blood continues to flow because of the anticoagulant. By the time the German couple alerted me, the leeches had grown to the length of my fingers and twice as fat, festooning my face. I spent the whole afternoon in my hotel room wringing the blood from my socks and wiping it from my chest and neck. Ah, but I had seen and recorded siamangs!