In the early 1970s young American primatologist Steven Green and his wife, Karen Minkowski were taken up with the world of lion-tailed macaques. At that time it was known from a limited number of researchers that working in the south Indian rainforest was very difficult. Torrential monsoon rains pelted those who undertook to investigate; leeches stuck to their bodies; snakes were a potential danger, and the steep and often slippery slopes challenged those trying to follow animals.

But these forests had lion-tailed macaques (LTMs). Among more than 20 species of macaque monkeys in Asia and in Morocco, this species has unique habits and habitats. Its striking black and white colouration contrasts remarkably with the drab beige and brown pelage of other species. LTMs spend far more time in trees than other macaques, coming to ground only to move across small open areas of forest or to feed on something that has fallen.

The published LTM lore fascinated Green and Minkowski. Their principal focus was to understand the lion-tails’ ecology and social behaviour as well as how they communicated both visually—through  facial expressions, tail position, body postures and gestures—but especially vocally. Previous research and animal communication theory suggested that limited visibility in the rain forest over the distances at which troop members dispersed—due to food distribution as well as differences in sound transmission in forest versus open habitats—would shape communication systems in LTMs to differ from those of other macaques that can typically see each other when communicating in more open habitats.

They settled on the Kalakkadu Forest near the southern tip of the Western Ghats in Tirunelveli and Kanyakumari districts of Tamil Nadu. The forest is now part of the Kalakkadu Mundanthurai Tiger Reserve (KTMR) which covers about 900 sq km and forms a part of Agasthyamalai Biosphere Reserve in Tamil Nadu and Kerala.

Green and Minkowski applied for and received a US government research grant, while the Bombay Natural History Society (BNHS) approved their request for collaboration and support during their study. Flush with curiosity and a sense of adventure, they applied for visas and research permits from the Indian government. But 1973 was not long after the Indo-Pakistan war of 1971, when the US had supported Pakistan. American researchers were not welcome in India and, indeed, the visas did not show up as expected. So Green and Minkowski, optimistic for a breakthrough, travelled to East Africa to visit friends, enjoy some wildlife viewing and to wait for the formalities to be completed. After several months, when visas still had not materialised, they flew to India as tourists to seek the help of the Bombay Natural History Society for permission to conduct their studies.

The BBTC tea estates golf course with the Agastya Malai in the background. The house n which Green and Minkowski lived is at left foreground. Photo: John Oates

For another two months they knocked daily on the doors of countless government officials in Delhi, only to be told that the particular official with whom they had to meet was “just coming”, or “having his tea”. At last, the assistance of Salman Haidar, who was then an aide to Prime Minister Indira Gandhi and also a relative of Bombay Natural History Society’s renowned ornithologist and naturalist Salim Ali, was invaluable in this long and tortuous process. They met Haidar and he somehow worked his magic within the government. Not long afterward, they became the first Americans after the Indo-Pak war to be granted visas to conduct research (according to Indira Gandhi: A Life in Nature by Jairam Ramesh).

In talks with BNHS about where to study the monkeys, they had settled on the Kalakkadu Forest near the southern tip of the Western Ghats in Tirunelveli and Kanyakumari districts of Tamil Nadu. The forest is now part of the Kalakkadu Mundanthurai Tiger Reserve (KTMR) which covers about 900 sq km and forms a part of Agasthyamalai Biosphere Reserve in Tamil Nadu and Kerala.



fter securing their permits, Green and Minkowski enlisted the support of the Bombay Burma Trading Corporation (BBTC), which had leased land from a local zamindar in 1929 for 99 years. BBTC had razed much of the forest and planted tea, eucalyptus, and coffee. In some areas, they removed only the understory and in its place planted shade-loving cardamom. While it has been recognised for many years that cardamom is harmful to a forest’s long-term health, these altered forests did provide habitat and food for tree-dwelling native birds, frogs, insects, and arboreal mammals including giant squirrels, Nilgiri langurs, porcupine, pangolin, the occasional bonnet macaque, the rarely seen Nilgiri marten, as well as LTM and other wildlife. These cardamom plantations were adjacent to the undisturbed habitat of the lion-tailed monkey in the Kalakkadu Forest. The company got income from selling timber and bamboo.

Lion-tailed monkeys tend to have small troops (about 8-20 individuals) with a single alpha male. Green and Minkowski’s primary study group had 12, and they also observed a second, much larger group.

BBTC offered them an unused stone bungalow in the Kakachi area of their Manjolai Plantation Estate for housing and headquarters. One can only imagine their relief and excitement at reaching the site from which they would launch their research. Although not electrified and very basic, the house was perfect for their needs. It had two bedrooms (one became an office/guest room), a bathroom, a dark, smokey kitchen with a fire pit and a vegetable garden in the back. Though the roof did not leak, the house was frequently damp with the high humidity in an area that got about 150 inches of rain per year.

Green grooms Minkowski the way macaques do. Photo: John Oates.

They hired a field assistant and a cook, who prepared curries for dinner and in the evenings left them each two pieces of French toast for their very early breakfast, which Green and Minkowski ate cold with jam. On more leisurely days, the cook made delicious dosas with coconut chutney. A cat, whom they named Poona, adopted them and eventually transferred his affections to the next researcher, John Oates, who assumed responsibilities for him. For the next 19 months Green and Minkowski inhabited the world of lion-tailed macaques.

The troop that Green and Minkowski soon focused on was somewhat habituated to the workers, who tolerated their presence in the cardamom fields that formed one small part of their large range. It did not take long for the monkeys to accept Green and Minkowski as two among many other forest creatures, and they could at times observe them at close distances (5-10m away) when the monkeys descended into the lower levels of the nearby uncleared forest.



ion-tailed monkeys, unlike many other macaques, tend to have small troops (about 8-20 individuals) with a single alpha male. Green and Minkowski’s primary study group had 12, whom they came to know very well and, as opportunity allowed, they also observed a second, much larger group and did a census of the composition of others when they were encountered. One of their greatest joys and privileges—for which primatologists travel and live in faraway places—was getting to know a group of monkeys individually and intimately over many months.

Each monkey in the smaller troop was named according to some physical characteristic or by assigning a name appropriate to a particular individual’s behaviour or other attribute. An older female with one stretched, sagging nipple soon became “Nip”. Sam was a handsome Sub-Adult Male and LJM a feisty Little Juvenile Male (aka Little Jack Macaque). Lief was the troop’s leader and the only fully mature adult male.

After some time Green and Minkowski could recognise individuals from their gait or posture, even from a brief glimpse through the foliage, much the same as one recognises another person at a distance without seeing their face. They never interacted with the monkeys—nor the animals with them—yet the monkeys became their friends, even their children (they had no children yet). Over meals, they gossiped and worried about them, laughed at their delightful or at times gross (by human standards) behaviours. Green and Minkowski were privileged to see behaviours that are revealing or significant but occur rarely, perhaps because of some unusual event.

Once, when Lief went missing for a day or two, Nip wailed during most of his absence, apparently totally bereft. In the 1970s researchers were loath, or at least reluctant, to attribute emotions to their study subjects. And while one perhaps still can’t write about an animal’s emotions in a scientific journal, it was clear to Green and Minkowski that Nip was grieving. They once watched a young adult female carrying her dead infant, probably her first-born, for a few days, until finally letting it go. Perhaps she felt sad and bewildered and experienced the loss of her infant much as a human mother might.

Another one-time observation was when Sam allowed a juvenile female to sit facing him and pick masticated food from inside his mouth, which she then ingested, behaviour resembling trophallaxis—transfer  of food—in insects. Perhaps Sam was courting a future mate? Feeling generous towards a youngster? Who knows? Minkowski saw this on one day, for a few minutes only, and never again. However, they frequently observed intimate food sharing between mothers and their youngsters. Infants and juveniles, unable to handle or open the spiny Cullenia fruits or break apart Artocarpus, would grab scraps dropped from the mouths of adults, who are not tidy eaters. Sometimes the young ones descended to the ground to scavenge bits of fallen fruit. Nor was it uncommon for the large sub-adult and adult males to allow females and youngsters to pick up scraps from the huge, wild jackfruit (Artocarpus heterophyllus) that only the big males could break open with their large canine teeth. 



ion-tailed monkeys intrigued Green and Minkowski more and more. They are exquisitely beautiful with their striking pelage of sharply contrasting black and white areas. In this sexually dimorphic (when males and females have different characteristics beyond the difference in sexes)  species, the males’ huge temporal mounds house the jaw musculature that gives them access to jackfruit. It also combines with the impressively large canine teeth to yield an imposing open-mouth threat display to rival males. These monkeys walk through all strata of the forest with deliberation, stopping to scan the near environment for insects, small vertebrates, or a piece of fruit, always with an apparent sense of confidence in their stride.

Many of the fruits ripen among all the trees of that species synchronously, so a particular fruit can be abundant throughout the forest. That’s not so with figs that are asynchronous with widely scattered trees. At times a troop abandons its leisurely movements through the canopy and makes a rapid beeline for a specific and distant fig tree, as though it retains a memory from previous years that the tree would now be fruiting.

When a sub-adult or adult male encountered a dead limb, he would often jump up and down on it, moving quickly back to a safe branch just before it broke from the tree and fell. Was he displaying his strength? Making the forest safer for his mates?

Green and Minkowski spent hundreds of hours following Lief’s small troop as well as a larger troop that was a little less tolerant of their presence, fleeing or freezing when they were too close. Besides following the monkeys on monthly, consecutive five-day dawn-to-dusk observation periods, they monitored the fruiting and leafing cycles of selected food trees on a monthly schedule and mapped trails cut by their field assistant. Maps facilitated following the monkeys through the forest, tracking their locations for various activities and calculating the distance travelled daily.

In the 1970s field maps were produced by hand using a compass, range finder and calibrated pacing to record the data, which were then drawn on paper. This was well before GPS, GIS, Google Earth, and waypoints simplified this task. 

Dense patches of treacherous spiny cane palms, impenetrable bamboo patches, steep slopes and sheer granite outcroppings often hindered a straight follow of the lion-tails, so mapping, tracking, and following the monkeys was often physically and logistically challenging. Their field assistant constructed log bridges across streams, but they were often swept away by the torrential monsoons and had to be rebuilt.



he study area’s rain forest was dominated by the 20-50m tall Cullenia excelsa trees, making this extreme southern part of the lion-tailed monkeys’ range very different from the dipterocarp-dominated (tall, tropical hardwood) forests further north. The primarily frugivorous lion-tailed monkeys ate mostly the fruits of Cullenia, Artocarpus (jack fruit), and Ficus sp.(figs). Their daily movements through the forest were apparently determined by the availability and distribution of these and other fruits. Cullenia and Artocarpus are abundant through the forest, and when their fruits were ripe, the troop would not cover much territory on a given day. When food was readily at hand, the monkeys spent substantial parts of the day grooming each other, napping, and especially among the juveniles, play-chasing or wrestling.

Insects were an important source of protein and fat in their diet. Huge walking stick insects, caterpillars and smaller, unidentified insects were grabbed and eaten with obvious relish. Minkowski confessed to having involuntarily averted her eyes to avoid the sight of the greenish gooey insides gushing from a caterpillar bitten in two by a lion-tailed monkey. They consumed even caterpillars with stinging spines, using a leaf as if it were a glove to roll them back and forth on a branch until the yummy larvae could be safely handled and ingested.

The couple had infrequent run-ins with elephants, primarily in the bamboo areas but also in the rain forest. Minkowski remembers walking alone along a dirt road in the forest and hearing the clang of a bell behind her. She turned to see an elephant used in logging operations lumbering up the road and quickly descended a steep forested slope to avoid a potentially serious encounter.



hey were fortunate enough to have rare close-up views of other infrequently seen forest-dwellers. A group of dhole approached Green once high up on a sparsely vegetated ridge. Sambar were heard from time to time crashing through the undergrowth. The only leopard they saw—though leopards must have seen them from time to time—was one caught in the headlights of their jeep as they were returning home from the forest one night after “putting the monkeys to bed”. (To ensure that the animals will be easy to find the next morning, it is common practice for researchers to wait until they have settled down for the night and then to head out into the forest before dawn the next day to be with the monkeys when they awaken.)

John Oates in the field in Liberia in 2011. Photo: Elizabeth Greengrass

Green and Minkowski saw relatively few snakes but always had to be alert while climbing the steep slopes not to mistakenly grasp a green pit viper when grabbing hold of a small branch. King Cobras are very large snakes that eat other snakes and therefore do not tolerate large mammals (like people) in their hunting zone as they inhibit the presence of the cobra’s prey. Unwittingly, Green parked the jeep in one such cobra’s hunting zone, and when he was retrieving the vehicle one evening, it raised its forebody, an imposing and somewhat frightening sight. Green was very wary when parking in the same spot after that.

During the rainy seasons, leeches bloodied their shirts and socks, in spite of always tucking their pant legs into their boots. One evening when Minkowski bent over her soup, a leech dropped from her head into the bowl. Green once pulled a leech from her eyeball that had migrated there from her binoculars. At times they stood in the endless rains in plastic ponchos, recording their observations on somewhat waterproof paper, while the monkeys sat huddled together, trying to keep the rain from penetrating to their skin. Perhaps the greatest risk in the forest is that of getting lost or falling and twisting an ankle or even breaking a limb. For that reason, Green and Minkowski, often following separate sub-groups of a troop, used whistles to maintain contact with each other.

They each had one bout of illness soon after arriving in the Kalakkadu Forest. Green came down with malaria, which he may have brought from East Africa. Still somewhat weak from a recent and severe bout of amoebic dysentery contracted in Bombay, Minkowski awoke one morning to a leg turned septic, likely result of scratching a leech bite.

It became clear during the study that ongoing and planned harvesting of bamboo and timber were fragmenting the forest and decreasing available habitat, and Green and Minkowski grew increasingly worried about prospects for the long-term survival of lion-tailed macaques. Their ranging patterns included long forays from their most intensively frequented areas, apparently in order to take advantage of less common but nutritionally necessary food trees. In a forest fragmented into small patches and separated by substantial cleared areas, the almost completely arboreal LTMs would not have access to a home-range large enough to include these dispersed resources.



he influence of recent advances in island biogeography and population biology made it clear that small patches of forest were biologically the same as islands. Fragmentation would also reduce or eliminate the chances of inter-troop meetings, thereby minimising opportunities to share genes across troops. Thus, in order to ensure survival at times of food scarcity as well as to maintain genetic diversity, connecting isolated areas of forest already diminished in size was essential. 

Hydroelectric schemes, timber operations, and expanding agriculture can devastate forest integrity, but the effects of habitat loss can be ameliorated by interconnecting patches of high-quality forest with intact forest corridors. These passageways must be large enough to permit seasonal movements and must contain sufficient food trees for animals to travel from one area to a neighbouring one.

In preparation for their unavoidable departure from this magical forest and the ever-fascinating monkeys, Green offered John Oates, another young primatologist, a post-doctoral fellowship to continue research at the lion-tailed macaque site once Green’s personal presence was completed. Oates’ goal was to study Nilgiri langurs that shared the LTM’s habitat. He arrived in 1975 and provided in his book—Myth and Reality in the Rain Forest: How Conservation Strategies Are Failing in West Africa—some additional perspectives. He wrote that Green’s study group roamed not only the government-managed Kalakkadu Reserve Forest adjacent to the tea estate but also the forests on BBTC’s estate lands.

All this was especially important habitat for the lion-tails, Oates writes, because it provided a link between the protected forests that lay on either side of the estate. Oates writes that breaking this forested link would further fragment the already precariously small and scattered population of LTMs remaining in the wild, which Green and Minkowski estimated in 1975 numbered 195. Their talks with the local BBTC managers on the significance of the forest ecosystem were received politely and with interest, but these managers did not have the authority to affect the long-term plans for the plantation. They discussed the issues with higher-ups in the company and with Tamil Nadu forest officials. Their goal was to protect the corridor of intact forest through the tea plantations. The corridor is now known as the One-Mile Corridor.

In 1962, according to Oates’ account, the Papanasam Reserve Forest to the north of the estate in addition to the remaining zamindari forests of Singampatti had been constituted as the Manduthurai Tiger Sanctuary. Later, at the urging of Green, Oates and Indian conservationists, and once again with the assistance of Salman Haidar, the government granted Kalakkadu Reserve Forest sanctuary status.

During this time of actively seeking conservation measures Green and Minkowski started receiving threats to their life; one timber contractor put out a contract on Green’s life. The police alleged that they were spies and their walkie-talkies, with which they communicated in the forest, were confiscated.

The legacy of Green and Minkowski as well as Oates lives on: their focus on the behavioural study of the Kalakkadu monkeys, as well as the subsequent report that inspired the then prime minster to make Kalakkadu Reserve Forest a sanctuary. Indian researchers have made their scientific bones studying this area—this One Mile Corridor that Green, Minkowski and Oates helped protect. Research continues there, as does legal wrangling between the forest department and BBTC, whose lease is set to expire in 2028.

Now, 45 years later, their daughters grown up and independent, Green spends much of his retirement tending his organic fruit orchard, where he grows lychees, mangoes and specialty tropical fruits and helps small farmers in his area with their farming practices and with conservation to preserve the native Florida forests and wetlands essential to maintaining a healthy environment for wildlife, people, and agriculture.

Green also teamed up again with John Oates, this time on a project initiated and supervised by Oates, in Sierra Leone, where they were once again able to gain government protection for an endangered forest and its wildlife.

Minkowski travels often to the African continent to see wildlife and volunteer in development projects or in support of scientific research. She visited Bandhavgarh National Park about ten years ago to fulfil a lifelong dream of seeing tigers, something they’d missed during their research. When not travelling, Minkowski enjoys photographing nature, hiking and practising yoga.

The lion-tailed monkeys are always hovering somewhere in their minds and the beautiful memories linger.


(The author is grateful to Steven Green and Karen Minkowski, and John Oates for their unstinting help.)