As the climate crisis deepens, Indian scientists call for the conservation of caves

Justin Sumit Kumar’s typical day is rather adventurous – he helps scientists track birds in dark caves, that are difficult to access, and surveys them. His work also requires him to sift through bird droppings and record the observations. Many years ago, Kumar used these very tracking skills as a poacher. However, today, Kumar is a sought-after conservationist who works with scientists to conserve the caves and their biodiversity, in the Andaman islands.

Enabling nest collectors to become nest protectors

Kumar’s is a story of how a poacher turned into a conservationist. “He was always curious to know more about the various cave-dwelling species. He wanted to know why we do, what we do,” shares Manchi Shirish S., Principal Scientist, Sálim Ali Centre for Ornithology and Natural History (SACON), who along with his mentor (Late) Ravi Sankaran, worked with former poachers like Kumar, for about two decades to conserve the edible-nest swiftlet (Aerodramus fuciphagus) of the Andamans.

This cave-dwelling species was threatened by trafficking, as its nest (made from its own solidified saliva) was a much sought-after culinary delicacy in China. The team went on to script an important conservation success story, as it trained nest collectors to become nest protectors, promising them an alternate livelihood if the same nests are protected and harvested sustainably (i.e., after the young birds fledge). As this species made a remarkable recovery, Shirish began to study the bigger picture – the fauna of the caves – and how these swiftlets and other bats influenced life within the caves.

“Caves form an Oligotrophic ecosystem, which has no direct energy source – there is no sunlight or vegetation. Their primary source of energy comes in through either a bird’s or bat’s guano or droppings. Unlike bats, the swiftlets forage during the day and roost in the cave at night,” says Shirish. In his research, he found that invertebrates in the cave were exclusively dependent on the swiftlet guano or droppings. With caves having a microclimate of their own, he states that the cave-dwelling fauna could be even more sensitive to minor changes and climate change could exacerbate local extinctions. In the face of climate crisis, Shirish says that it is even more necessary to conserve cave systems which are an abode for diverse fauna.

The significance of cave data in understanding climate change

Geologists from different parts of the globe also study cave ecosystems to understand climate change better. Jaishri Sanwal Bhatt, a scientist from the geodynamics unit of Jawaharlal Nehru Centre for Advanced Scientific Research explains how data from the caves can be used to understand climate better. “In caves, you have structures like stalactite that hang from the ceiling to the floor of the cave and stalagmite that grows from the floor towards the ceilings. These stalagmites are very important as they preserve the history of climate. Stalagmites are basically deposited layer by layer, every year. They end up preserving data from their environment during the time of formation. For example, a 20 cm long stalagmite (found in a cave) may contain the data of a few centuries.”

“There is a saying that, the past has the key to the present. Our climate is also cyclic in nature. What we (geologists) do is basically reconstruct the past climate data. As for the present, we have instrumental data. With these inputs, computational experts can stimulate a model on how climate will behave in the future,” she tells Mongabay-India.

While Bhatt agrees that other systems can also be used for understanding climate, she opines that caves have an edge. “In the caves, data ranging from single year to decades, are recorded. Although a river deposits a lot of sediments which can be dated, when you have floods or heavy rains, it cuts its own deposit and takes it away – this could mean the loss of a thousand years of data. Water turbulence also disturbs data. In the caves, we have better chronologically controlled data, with an error margin of a minimum + or – 10 years. Whereas in lakes or rivers ecosystem, it could be anywhere between 100 and 1,000 years,” she says.

The urgent need for cave conservation

Despite their significant role, Bhatt believes that India has not done enough to protect the caves with fragile ecosystems. “In Northern India, caves are worshipped. And many people end up breaking speleothems (speleothem originates from the Greek words spelaion, meaning cave; and thema, meaning deposit) and taking it home for worship. If we can get people to see the science behind caves and its fragile ecology, it would motivate the local communities to conserve these caves instead of destroying them,” Bhatt tells Mongabay-India.

Shirish too states that not much has been done to understand cave ecology and the various species that have made it their home. “There is no law which talks about cave conservation in India,” he rues. Recently, Shirish and Dhanusha Kawalkar, Senior Research Biologist, SACON, initiated an effort towards conserving the cave-dwelling Indian swiftlet in Maharashtra.

Inspired by Shirish, his mentee Kawalkar, along with other researchers, started the Speleological Association of India in September 2021, to further the understanding and conservation of caves, subterranean ecosystems and other habitats in the Indian subcontinent.

“We are a group of nine researchers, with different interests and expertise (including geology, archaeology, bio-speleology, cave diving, etc.), who have come together to form the Speleological Association of India,” shares Dhanusha Kawalkar, who is also one of the Directors of the Association. Kawalkar points out that though India has been interacting with caves for centuries, the studies have primarily focused on geology, and speleologists mostly limit their work within a state or a district. “We wanted a pan continental association that supported exploration, research and advocacy of caves, one that also addressed threats above surface like land use change and enabled restoration of caves through community initiatives,” she elaborates.

Highlighting that there are also many significant cave systems in India where huge rivers originate, Kawalkar states, “These subterranean wetlands are a major source of water.” Why then have the caves not been studied properly? “It’s their inaccessibility which is the reason,” she responds.

When the natives with knowledge of the ecosystem become field assistants

Kawalkar recalls that her own exposure to caves was initially for spiritual purposes, “As a child, I used to visit cave temples often, but there was no opportunity to explore beyond that.” It was only years later when she joined the SACON that worked on conservation of swiftlets in Andaman, that she stepped into caves again. “There were close to 400 caves and I remember becoming a child again in my first encounter. The locals who worked as field assistants with us also pitched in with their own ethno-speleological knowledge – they guided us on where to sit, what not to touch inside a cave, the local names for the flora and fauna and even their characteristics,” she narrates.

Much before the scientists came in, the locals were involved in trafficking the nests of swiftlets, “About 35-40 years ago, people used to take a fire lamp and wait outside caves for the birds to come. The swiftlets used a peculiar sound to echo-locate their nests and that is how the nest collectors found the swiftlet colony. Till date, it is this basic technique that helps researchers like us track the colonies and estimate the bird population sizes.”

With thousands of caves spread across the country, Kawalkar believes that it is a necessity to rope in local people even to map the cave geo-location and biological diversity. Having mapped more than 100 caves (in the Andamans and Maharashtra) with Shirish, she often depends on the local community to discover more caves.

Apart from the knowledge locals bring to the table, Shirish opines that it is vital to get them involved for the sustainability of any conservation programme. “Whatever conservation we are doing, we do it for the local people, the ecosystem and the resources in that place. Therefore, the locals are major stakeholders – they should have the rights and responsibilities to work for the betterment of resources and land.” Kawalkar adds, “Perhaps, we could declare certain areas with high cave density as community reserves, where the community can have the entire right on the management of these habitats.”

Read more: Andaman forests need longer intervals between repeat logging for recovery: study

Banner image: Kawalkar at a limestone cave in the Andamans. Photo by SACON.