It was love at first sight. As a postgraduate student, Narayan Sharma was conducting a primate survey in Hollongapar Gibbon Sanctuary, Assam, when he saw a troop of stump-tailed macaques. “They are so graceful, unlike the other macaque species,” he says. “I wanted to work on them for the rest of my life.”
Even a brief spell studying the western hoolock gibbon, which is “the darling of everyone,” didn’t change his mind. For his doctoral thesis, he followed the stump-tails in the 21-square-kilometre park. Sharma was immediately struck by how differently they behaved compared to related species. Unlike northern pig-tailed macaques that split into smaller groups and merge again, stump-tails live in large troops.
The two troops that the researcher studied had more than 100 members each. One of them grew to 194-strong in December 2016, the largest group on record. In a video recording, the animals streamed across the open grassy ground for almost 10 minutes.
Sharma and his assistants rose at 4 a.m. every day to reach the roosting tree. Nothing beats the revolting stench of all-night pooping to slap one awake. Perhaps the macaques’ diet of herbs and shrubs makes their dung smell extra rank. Even a wayward sticky excrement falling on the researcher’s knapsack, a common occurrence while working with monkeys, was enough to ruin his day. After a few minutes of grooming each other, they set off to forage, much to Sharma’s relief. Whether they hold their breath when they descend isn’t known.
Unlike other macaques, the hefty red-faced primates don’t venture into the surrounding villages looking for handouts. Instead, they spend most of the day on the ground, stuffing their mouths with fruits, mushrooms, and bamboo shoots, as well as slugs and frogs. Their favourite is the root of a perennial shrub of the dayflower family, locally called athubhanga . It is so widespread throughout the sanctuary that it allows the animals to live as a unit, says the researcher. Elephants browse on the same bamboo clumps and fruits, making encounters inevitable.
“Forget gathering data,” says Sharma. “We run for our lives. Those are sad days, as it would take two to three days to find the troop again.”
Researchers don’t write about these hardships in their scientific reports. “No reviewer counts the number of times elephants have chased a researcher,” he says. “All I have to show after 22 months of fieldwork is a single graph.”
As daylight faded, the macaques wound up their foraging. The older females led the rest to their sleeping tree while the watchful males guarded the periphery. They selected the tallest trees, in whose heights they can be secure from leopards. As many as 20 huddled together on a branch close to the main trunk “like birds on a wire.”
Despite the size of the troop, there’s no more than low-grade conflict among the members. Stump-tail society is calm, with every member getting along with everyone else. If any differences erupt, they reconcile and make peace. Rhesus, for instance, have shrieking fits. In many ways, stump-tails don’t behave like other macaques. “They should be classified as apes,” jokes Sharma.
They are, however, not above engaging in cheek-pouch robbery. Stump-tailed macaques typically cram their cheek pouches with fruit, looking as if they’ve tucked two tennis balls below their lower jaws. Later, when they relax in the shade, they leisurely chew and savour the juicy goodies. Bossy adults pry open youngsters’ mouths and steal their saved meals.
“The most surprising thing about them,” says Sharma, “is they never threatened me.”
An adult male brushed past, a liberty that the researcher would not grant to rhesus macaques. On another occasion, a mother walked away to look for athubhanga or mushrooms while her ivory-white young gambolled near Sharma. Protective mothers of other macaque species sweep their babies towards their bellies, where the little ones cling until the coast is clear.
This trust didn’t come readily. The stump-tails didn’t take to Sharma at first sight as he had to them. While he observed their gracefulness, they watched him from a distance. It took two months to pass their test.