HIGHLAND HIERARCHY

de Silva Wijeyeratne, G. (2005). Highland Hierarchy. LMD. June 2005. Page 192. Volume 11, Issue 11, ISSN 1391-135X.
Being treated as a subordinate male by a monkey in Hakgala.
Gehan de Silva Wijeyeratne finds himself treated as a sub-ordinate male

The lips curled back exposing a pair of sharp canines. Long daggers, which have evolved for warfare with rivals and to deliver a killing bite to prey. I was not close enough, to be the reason for the threat yawn. It must have been directed at another male. But I became even more mindful not to approach this particular male any closer. I was at Hakgala Botanical Gardens with members of my team from Eco Holidays. Ahead of me, Chinthaka de Silva was leading a group of clients on a mammal watching tour. The botanical gardens in Hakgala seems an unlikely place for mammal enthusiasts. It is more likely to attract picnickers and horticultural enthusiasts.

But the gardens are surprisingly good for wildlife. This is because the summit of Hakgala Peak is clothed in cloud forest. There are also significant areas of cloud forest in the area around the botanical gardens. Not surprisingly, many endemic birds and animals visit the garden. These include the endemic Rhino-horned Lizard and birds such as the Dusky-blue Flycatcher.

It is also the best place in Sri Lanka to see close up, the usually shy Bear Monkey. The Bear Monkey is actually not a ‘full species’. It is a sub-species of the Purple-faced Leaf Monkey. The Leaf Monkey is widespread, seen even on the outskirts of Colombo. But it is relatively shy everywhere. The Bear Monkey, which ascends to the Horton Plains National Park, the highest plateau of Sri Lanka, is also very shy. Except, that is at Hakgala. Over decades, the Bear Monkeys of Hakgala have learnt that humans mean it no harm. They remain relaxed and comfortable in our presence. This is why Chinthaka and his group of mammal watchers had arrived at Hakgala.

There was another mammal at Hakgala which also interested us. This was the widespread Toque Monkey or Toque Macaque. Like the leaf monkey, it too has a few sub-species, including a highland race or sub-species. The threat yawn I had observed was from one of them. One thing common to both sub-species is that they have evolved a thicker coat, to keep them warm in the cold highlands. In the Bear Monkey it is very pronounced. They have very thick coats, hence the name Bear Monkey. They look cuddly and huggable and are very popular with visitors. The Toques on the other hand, always look a touch sinister and dangerous. The highland race has another distinction, besides a thicker coat. On its head, it has a pronounced bonnet of hairs, which extend well over the eyes.

The Leaf Monkeys are almost entirely herbivorous and feed on leaves. The Toques are omnivorous and feed on almost anything. Whilst the Bear Monkeys have accepted humans with a gentle tolerance, the Toques treat humans with an air bordering that of contempt. I remember listening to a lecture delivered by Dr Wolfgang Dittus, who explained the psychology of the Toque Monkeys with reference to his study in Polonnaruwa. This study is one of the longest running field studies in the world. Very few people understand primates the way Dr Dittus does. He explained to his audience how primate society is very hierarchical. Low ranking males and females, are at times forced to give up food by more domineering, higher ranked members of the troop. When people offer food to Toques, in their social framework, it is the gesture of a lower ranking animal, confirming our sub-ordinacy. This encourages Toques to become bold and aggressive.

Of course it is not so simple. People can also be aggressive towards the monkeys and maim or kill them. So the Toques exercise a mix of caution coupled with an air of superiority in dealing with its genetic cousin.

One middle ranking male, whom I nicknamed Pest, was suffering from mixed signals from its primate cousin. He was on the way up in the hierarchy and was spoiling for a fight. Pest was perhaps just two or three years old. But what he lacked in body mass, he made up in boldness. He had evidently got used to the idea that with a touch of aggression, people would beat a hasty retreat. He began to pester me with a series of challenges. My photography of the Toques would be interrupted by Pest walking up to me and making swipes at my tripod. Next it would be me! The prospect of a pair of vicious canines sinking into my legs was sufficient to elicit a suitably primate response from me, shaking my camera and tripod in mock aggression. Pest was trying to use me as a proxy, a soft target, to impress the girls and the boys of his prowess and move up the ladder.

The Leaf Monkeys also occasionally bore the brunt of the ill tempered Toques. Most of the time, both species would feed peacefully by having different foraging strategies. The Leaf Monkeys kept to the canopy and ate tender leaves. The Toques foraged on the ground, especially keeping an eye open for scraps of food. At times, the Toques would also go after the tender leaves. In any inter-species aggression, the Leaf Monkeys, although bigger, would back down. The Toques canines and temperament make them a fearsome adversary. In fact many observers have noted Toques appearing to mate with another primate, the Hanuman Langue or Grey Langur. Dr. Dittus, explained to me that this was a dominance display, not an act of attempted copulation. Even amongst themselves, monkeys are prone to do this. I remember observing Baboons in Nakuru National Park. Some of the older males mounted some very young baboons. Raju Arasaratnam who was with me was startled that an old male would attempt to mate with another so young. The answer as explained, was it was not for mating, but to establish the pecking order.

We observed another Toque male, which was keeping to the periphery. Often, the younger males stay at the periphery of the troop. But this was not a young male and looked a very senior male. I suspected that he may have been a previous alpha male. When alpha males are displaced by challengers, they often plummet down the rankings, to the lower order. Many find their fortunes have reversed sharply and are treated with contempt by their former sub-ordinates. As a result, former alphas are often reduced to sub-ordinates on the periphery of the troop. The old male, leisurely walked over to a rock where my colleagues Ajanthan and Aruni were seated. He sat behind them and played with himself. Although he showed no signs of aggression, Aruni and Ajanthan were gently alerted that their genetic cousin was seated less than a foot behind them. Whilst Aruni reacted in horror, Ajanthan was bemused. Both moved away, carefully, leaving the male, whose attention was soon diverted by a female of his own kind. As the sun rose, the young monkeys of both troops began to play. Training for the days when they will challenge each other for a place in the hierarchy.

The writer, is the CEO of a wildlife & luxury tour operator. Averaging weekly media appearances, he is a well known wildlife populariser & tourism personality. E-mail him at gehan@jetwing.lk to subscribe to his wildlife e-newsletter.