By Adity Choudhury
The celebrated English primatologist, Dame Jane Goodall once said, “You cannot get through a single day without having an impact on the world around you. What you do makes a difference, and you have to decide what kind of difference you want to make.”
Her haunting words reflect the urgency of conservation, rooted in science.
The human imprint has left an inevitable mark on the planet, with many species gone extinct over a period of time. The role of conservationists, therefore, is significant to ensure balance, despite the challenges of conservation.
Divya Vasudev knows this too well. She completed her PhD on the western hoolock gibbon in the Garo Hills for her doctoral thesis from the University of Florida.
She worked with the Wildlife Conservation Society’s India programme for few years and was awarded the Department of Science and Technology (DST) INSPIRE Fellow via the Centre for Wildlife Studies through a science institution.
In 2017, she along with Varun Goswami, started Conservation Initiatives (CI) based in the North East.
They offer both research and conservation programmes that work parallelly. Assam, Meghalaya, Nagaland and other parts of India make up the CI team.
“We felt the need for a science-based approach in conservation of wildlife and ecosystems, in addition to providing skill development and career opportunities for people in the North East who are interested in conservation,” she said.
In her own words, “We believe in a solid boost-on-the-ground approach. Local contexts are important where conservation work is concerned. We believe in participatory approaches, and work with forest department officials, local communities, and private landowners. Two projects – elephants and gibbons – are our flagship projects at the moment.”
But before we delve into their Gibbon Project, let’s get to know the only ape species found in India.
Genetically Closer
There are great and lesser apes – gibbons are part of the latter group.
“Chimpanzees, orangutans and gorillas are called the great apes while gibbons are lesser apes. In Africa, you will find chimpanzees and gorillas while in South East Asia, you will find orangutans and gibbons. The Western Hoolock Gibbons are found in India, Bangladesh and Myanmar, which makes it really special. Interestingly, not many people here in India know about them being closely related to us or their ecological significance,” Vasudev said.
As a diurnal species, most activity is observed during the day. Being arboreal, they live on trees. Their quiet, agile and graceful movements (brachiation) from one tree to another makes for an experience.
In Vasudev’s words, “They use their arms to propel themselves from one branch to another. It’s like watching a trapeze act in a circus, and makes for a truly amazing observation experience. They’re super quiet and graceful.”
She also spoke about their genetic closeness to humans. One of their distinct characteristics is their call (or song). In her words, “Each gibbon has a call, a song known as the duet. The entire forest reverberates with their song. No two duets are the same. This points to their superb intelligence as well.”
Their importance in Meghalaya is evident from her words. People of Hima Malai Sohmat, a cluster of villages in southern Meghalaya along the Indo-Bangladesh border, believe that the boundary of the Hima is marked by the gibbon call.
They announce their presence through their calls. People may get an idea that there are 1000 gibbons around because of their loud calls, but that’s not the case, as they operate in small numbers, making them different from, say, macaques or even langurs.
Referring to this, Vasudev highlighted their monogamous nature, with a family-based social structure. Not only do they form nuclear families, but they don’t seek out companions unless death claims one of them.
She pointed out how they go quiet once dusk sets in.
Vasudev recalled how close she got to families during her research. “How close one can get to a western hoolock gibbon is a parameter to know whether they perceive you as a threat,” she said, adding once they stop their calls, they go completely silent.
No wonder then that scientists say we share 90 per cent genetic similarity with them.
Following the gibbon footstep
On her interest in the western hoolock gibbon, Vasudev shared her fascination with primates since a young age. “Observing primates is interesting from the perspective of animal behaviour.”
This coincided with her interest in conservation. During her PhD, she became interested in species dispersal and connectivity, a unique part of conservation that is very important today.
Vasudev said, “Today, forests are small and fragmented, and our animals need to move via corridors, through forests or other land uses. While they’re dispersing, they’re suddenly faced with important decision making in unfamiliar systems. They ask themselves if they should move through a human habitation or come down from trees, given the extent of forest loss. New risks also mean newer models of adaptation.”
The concept of connectivity model, in her words, mean their survival is taken into account. “We make assumptions of some of their decisions and create connectivity models to ensure species’ persistence through, say, creation of corridors and movement zones for smooth dispersal.”
Her field work in Garo Hills cemented her interest in the western hoolock gibbon.
At that point of time, they were found in village forests – each village has their own small forest fragment – one or two western hoolock gibbon groups lived there. Her in-country collaborator, the Wildlife Trust of India (WTI), ran a project to help the community conserve some of these forests.
Vasudev wanted to contribute through sharing knowledge. “I wanted to provide information on the network of forest fragments that could be conserved best to save the system. This was the perfect juxtaposition of observing animal behaviour and conservation – it fit with my scientific work that needs to address conservation challenges immediately.”
Challenges of Conservation
Unfortunately, the western hoolock gibbons are an endangered species.
“In 2009, they featured on the top 25 ‘most endangered’ primate species across the world. It was a list prepared by the international IUCN primate specialist group. All types of primates were mentioned here, requiring conservation attention. Presently, its name is not featured on this list,” she shared.
They are dependent on the forest. Forest loss and fragmentation have contributed to their lower density. As Vasudev examined, “Large swathes of land are often converted for agriculture. In Meghalaya, it has been rubber and areca nut plantations while in Assam, in the past, it was tea estates. Even now, forest loss to agriculture and plantation continues.”
“But fragments still remain. Around Nongkhyllem Wildlife Sanctuary for instance, there are still woodlands left. Gibbon groups can exist in these woodlands, but they’re restricted to a small fragment. Where forests are scarce, specific needs need to be taken into consideration – remnant vegetation, fig trees and other food trees, and tree cover – necessary for their survival,” she added.
Poaching is a cause of concern, because of which they have gone locally extinct in certain places. As per expert estimates, about 90 per cent of the western hoolock gibbon population have potentially gone. It’s also difficult to ascertain the exact number because of lack of information on how many families existed in the past.
A Gibbon-y Anecdote
In one of her on-field experience, an interesting situation developed.
Along with her field assistant, Vasudev was following a family, when they realised the male western hoolock gibbon was not present. Concerned, both of them searched for him.
Meanwhile, they could hear music playing somewhere. While the assistant traced the male gibbon to this place and found him, she kept an eye on the female and the young ones.
“My field assistant came back with a wide grin and shared how he (male gibbon) was listening to the music. What is amazing is how he returned and joined his companion once the music stopped,” Vasudev said.
Another funny incident happened in one of the villages of Garo Hills.
In recalling this incident, a giggling Vasudev shared how she was told that they threw up on women, while men were allowed to go near gibbons. Curious, she ventured inside a forest and found out that it was a different call, a guttural sound – aa aa aa – that gives it the appearance of a retching sound.
She said, “If you get too close to a gibbon, this is a warning call. That’s when I realised that they did not vomit on women, they were just warning them that they were too close!”
Such anecdotes are reminders of the fragile human-animal co-existence.
As per the International Union for Conservation of Nature (IUCN) Red List of Threatened Species website, the western hoolock gibbon falls under “Endangered” category, based on an assessment from September 2017.
In this light, isn’t the onus on us to save the western hoolock gibbon?
The answer lies in Goodall’s quote reminding us of how individual decisions make a difference. If the choice is given to you…wouldn’t you prefer to see a western hoolock gibbon listening to the radio, rather than it becoming a bedtime story?