Scientists at the Yerkes Regional Primate Research Center in Atlanta, Ga., are sewing the eyelids of infant primates shut to see how that affects their behavior. At the New England Regional Primate Research Center, a database is maintained of self-inflicted wounds — fingers bitten off, holes chewed in arms — among populations of normally social monkeys kept in solitary confinement.
Welcome to the world of primate behavioral science!
We hopped aboard an Air Lanka jet to see if there might be a viable alternative way to investigate simian behavior. A way of learning about our closest biological relatives without having to resort to the kind of experiments that — when applied to human subjects — incurred some stiff penalties at the end of World War II.
We found it in the form of the Toque Macaque Research Project in the ruins of Sri Lanka’s Polonnaruwa.
Polonnaruwa is 216 km northwest of Colombo, at the heart of Sri Lanka’s Cultural Triangle — made up of the three ancient cities of Polonnaruwa, Sigiriya and Anuradhapura.
Polonnaruwa was founded by the armies of the Southern Indian Chola Dynasty (dominant ca. 850-1279), who swept down into Sri Lanka in the 10th century.
They liked the site for several reasons. Principally because it was a strategic location should the indigenous Ruhunu Sinhalese revolt but also, apparently, because it had fewer mosquitoes than the former, much older capital of Anuradhapura.
The Cholas didn’t last long. The Sinhalese king, Vijayabahu, evicted them in 1070, but maybe the lack of mosquitoes appealed to him, too. He decided to retain the city as his capital. Between 1153 and 1186 was a golden age in Polonnaruwa, as King Parakramabahu I set about an extraordinary series of developments. He built parks, erected huge temples and palaces, sank lotus ponds and excavated a 2,400-hectare reservoir, or tank, so large that it is still known as the Sea of Parakrama.
Then his successor, Nissanka Malla, blew it. Determined to outdo his predecessor, he launched into an even more frenetic construction binge that virtually bankrupted the kingdom. One of his more eccentric feats was the carving of a colossal stone book, the Gal Pota. The book, which weighs 25 tons, was hauled into Polonnaruwa from the holy city of Mihintale, nearly 100 km away. It extols Malla’s virtues but makes no mention of his fiscal mismanagement.
Malla, despite his flawed grasp of economics, was one of the world’s first conservationists. Inspired by Buddhist teachings, he forbade the killing of any animal within seven gaw (about 39 km) of the city limits.
Short of cash and under pressure from Southern Indian incursions, post-Malla Polonnaruwa went into rapid decline. For centuries Polonnaruwa was smothered in jungle, all but forgotten, home not to people but to leopards, macaque clans and solitary rock pythons.
It was the monkey population, rather than the ruins, that brought German researcher Wolfgang Dittus to Polonnaruwa. His logic was simple, by the standard of international primate behavior science: Rather than cloister himself in a laboratory committing atrocities, he watched monkey behavior in the wild. And so began a 32-year continuous study, one of the longest of its kind in the world.
Although Dittus is also conducting work on Polonnaruwa’s primate populations of langurs and slow lorises, he is mainly focusing on the toque macaques. Indigenous to Sri Lanka, toques weigh between 3 kg and 5 kg, are highly social and have their own individually distinct “hairstyles” as well as cheek pouches to store food. There are approximately 1,000 of these hyperactive, long-tailed primates in Polonnaruwa, divided into 34 social groups. There are few natural predators, with the exceptions of pythons and monitor lizards, and the “Temple Troop,” as they were dubbed by a BBC documentary crew, pretty much rules the roost.
Dittus, with the help of volunteers, simply follows them around observing their behavior, social interactions, feeding and breeding patterns — in short, everything that makes a toque tick.
For many visitors to Polonnaruwa, the monkeys, like the birds, lizards and butterflies, are simply a colorful backdrop to the ruins themselves, but when you closely observe the toques, you are drawn into a simian soap opera of epic proportions. There’s a lot of fun — playful youngsters rushing through the temples and scampering over the ancient walls and columns. There are moments of tenderness and grooming. But there are also instances of brutality, even wars that flare between the different factions.
Immediately obvious is the fact that each toque has its own distinct personality and that each family unit is in a constant process of adjusting its behavior to cope with changing circumstances. As one volunteer from San Francisco put it: “They’re very human.” One wonders how many more cruel laboratory experiments will be carried out before the white-coated behavioral scientists reach a similar conclusion and wrap up their studies.
Accommodation for volunteers is with the Dittus family; clean and simple, with delicious home-cooked Sri Lankan meals.
If a week or more of full-time monkey-watching doesn’t appeal, Polonnaruwa is still a must-see on any visit to Sri Lanka. The ruins are in a better state than the much older ones at Anuradhapura. They have been partially restored and are interspersed with patches of jungle and tropical gardens. A cleanup campaign launched by Dittus has removed the unsightly litter that mars some of Sri Lanka’s architectural treasures.
Wild elephants no longer enter the ruins, but every day at dusk and dawn, they can be observed drifting out of the tropical forests to drink at the nearby tank and graze on the floodplains.
There are a number of attractive little villages in the vicinity that can be explored by rented bicycle or on foot — bicycle is also the best way to explore the ruins. There is a range of accommodation from backpackers’ lodges to several first-rate hotels sensitively designed to blend with the landscape.
Two of the other main Cultural Triangle attractions lie within easy day-trip distance of Polonnaruwa: Anuradhapura and the dizzyingly high plateau palace built by “Mad King Kassapah” at Sigiriya.