It started just like any other day. By 8am we were in field in a community forest nearby Mandal, a sleepy little village at the base of a steep valley of the Garhwal Himalayas, India. Sunrays were just kissing the hilltops. But we and our Central Himalayan Langur troop were deprived of the warmth of the sun. To stay warm, the langurs were huddling and sharing body heat with each other on the forest floor. We made note of this kleptothermy–a behavioral adaptation to fight the chilling temperature—in our data sheets .

(Huddling)
Central Himalayan Langur (Semnopithecus schistaceus) was a relatively unknown species. In India, it ranges in the high Himalayan elevations (1,500-4,000 m) from Jammu and Kashmir to Sikkim. It is primarily greyish in appearance with a whitish head and tip of tail, with a relatively larger body size (avg. 70cm) than other langurs—though females are generally smaller than males. In this species, multiple males share domination over the troop; the group we were following was a large group with 5 adult males, 12 adult females, 7 sub-adults, 8 juveniles and few infants.
We were observing the langurs in order to better understand their behavioral ecology; this required following the troop throughout the day – from morning (when they were still resting, not active enough) till evening (when they were moving towards their resting/sleeping site for the night).
On this particular morning, as the clock ticked forward, sunrays reached the treetops and all our huddling langurs now started moving upwards for a sun-bath. Others got busy feeding and a few were still in resting mode. We had been following the langurs for a month and were acquainted with their behavior. We anticipated they would move to some other location after having ‘breakfast’. Indeed, as per our expectation, they soon started to move towards the village. Their intention was clear: to feed on the crops!
The troop travelled along the upper part of the hill. There were hardly any houses over there and villagers also didn’t frequent that place often. The terrain was somewhat steep and had denser tree cover. Around 10am, part of the troop climbed down the cliff and settled themselves in the crop field, which provided a cool place, a short distance from the village, to munch on fresh green mustard and wheat leaves. Other langurs were on their way to join in.
The raid
Everything seemed fine until, suddenly, a few langurs ran away and began looking for cover in high tree branches. We knew this must be the dogs ‘employed’ by the villagers to keep the langurs at bay. Dogs generally raided silently: You didn’t see or hear anything except frantically running langurs.
What unfolded next was nothing our data sheets could quantify!
Two or three dogs invaded the troop, scattering langurs and trapping a few of them in the cliff area. At one point, over a dozen infants and juveniles, with just one or two adult females, were isolated on the cliff, guarded by a dog (D1 in the image below) that was determined to prevent them from moving into the crop field (Point A in the image below).
Whenever they feel threatened or isolated, non-adult langurs make a certain prolonged low pitched ‘keeee-ke-kee-ke-ke’ type call and scan intensely for help. Primarily composed of ‘kids’, the group of trapped langurs started to vocalize in this manner, asking for help!

Now, one adult male (AM1) suddenly came into picture. He was sitting on a high tree branch on the other side of the crop field (Point B), facing the sub-group left behind, with a second dog (D2) at his tail. He was scanning worriedly, looking for a chance to move to the rest of the troop. Could he initiate a rescue mission?
Rescue mission – phase A
The adult male (AM1) was only about 100 meters from the cliff – not much of a distance, but with two dogs lined up in between, the langurs would need to come up with a good plan.
A second adult male (AM2) appeared within a minute or so, positioning himself on a high branch of another tree (Point C) to the left of AM1, maintaining a little distance in between. Few other langurs were also scattered around here, where a third dog (D3) was on duty.
And now the action! AM2 moved towards a lower branch, within possible reach of the dogs, but at a sufficient distance to maintain safety. He acted as a distraction to get the dogs away from AM1 and give the latter an opportunity to run to the cliff. Without wasting a moment, AM1 climbed down and took a sprint. He avoided the dogs brilliantly and arrived at the cliff—where other members were waiting for  sprint. He avoided the dogs brilliantly and arrived at the cliff—where other members were waiting for help.
Rescue mission – phase B
Outsmarted and confused, D2 and D3 were now both at Point C. AM2 had not yet carried out the last of his plan. He provoked the dogs again, tricking them to chase him, eventually moving further away and out of sight. The dogs followed, and all we could hear was a little bit of barking.
AM1, now located at Point A, was appearing quite relaxed, and D1 must have felt dejected. With the exception of AM2, the troop were reunited and could wait without any hurry or worry for another opportunity to retreat under ‘cover’. For almost five minutes, nothing happened — nothing except D1 twice being attracted towards Point C and the other dogs. Finally, after a couple more minutes, D1 couldn’t resist the possibility of more action at Point C, and ran that way. This gave AM1 an opportunity to lead the rest of the troop members away; with a mixture of caution and speed, they sprinted towards Point A and kept right on going to a much safer location.
Mission accomplished with a sigh of relief.
Photo and sketch by author.
ACKNOWLEDGEMENT:
I am grateful to Himani Nautiyal, PhD student at Primate Research Institute, Kyoto University, Japan for giving me the opportunity to volunteer in one of her Rufford granted projects about Ecology of Central Himalayn Langur (Semnopithecus schistaceus).