- Cave ecosystems are little studied in India. A group of scientists established the Speleological Association of India last September to further the understanding and conservation of the caves, which contain data for understanding climate change and its impacts.
- The caves have their own microclimate. Cave fauna may be more sensitive to minor changes, and climate change could exacerbate local extinctions, scientists say.
- With thousands of caves spread across India, scientists say there is a need to partner with local communities to map their geolocation and biological diversity. They also suggest that local people have certain rights over the management of these ecosystems.
Justin Sumit Kumar’s typical day is quite adventurous – helping scientists track birds in dark, hard-to-reach caves and watching them. His job also requires him to sift through bird droppings and record sightings. Many years ago, Kumar used these tracking skills as a poacher. However, today Kumar is a sought-after conservationist working with scientists to conserve caves and their biodiversity, in the Andaman Islands.
Enable nest collectors to become nest protectors
Kumar’s story tells how a poacher turned conservationist. “He was always curious to know more about the different cave species. He wanted to know why we were doing, what we were doing,” shares Manchi Shirish S., senior researcher at the Sálim Ali Center for Ornithology and Natural History (SACON), who together with his (late) mentor Ravi Sankaran worked with former poachers like Kumar, for about two decades to keep the edible nest swiftlet (Fuciphagous Aerodramus) of the Andamans.
This cave-dwelling species was threatened by traffic, as its nest (made from its own solidified saliva) was a highly sought-after culinary delicacy in China. The team then scripted a major conservation success story as they trained nest collectors to become nest protectors, promising them another livelihood if the same nests are protected and harvested sustainably. i.e. after the young birds have fledged). As this species made a remarkable recovery, Shirish began to study the big picture – cave fauna – and how these swiftlets and other bats influenced cave life.
“The caves form an oligotrophic ecosystem, which has no direct source of energy – there is no sunlight or vegetation. Their main source of energy comes from guano or the droppings of a bird or of a bat. Unlike bats, swiftlets feed during the day and roost in the cave at night,” says Shirish. In his research, he discovered that the invertebrates in the cave relied exclusively on guano or the droppings of swiftlets. Because caves have their own microclimate, he says the cave fauna could be even more sensitive to minor changes and that climate change could exacerbate local extinctions. Faced with the climate crisis, Shirish says he is even more necessary to conserve the cave systems that are home to diverse fauna.
The importance of cave data in understanding climate change
Geologists from different parts of the globe are also studying cave ecosystems to better understand climate change. Jaishri Sanwal Bhatt, a scientist with the Geodynamics Unit of the Jawaharlal Nehru Center for Advanced Scientific Research, explains how cave data can be used to better understand climate. “In caves you have structures like stalactites that hang from the ceiling to the floor of the cave and stalagmites that grow from the floor to the ceilings. These stalagmites are very important because they preserve the history of the climate. Stalagmites are basically deposited layer by layer, each year. They end up preserving the data of their environment during the time of their formation. For example, a stalagmite 20 cm long (found in a cave) can contain the data of a few centuries.
“There is a saying that the past is the key to the present. Our climate is also cyclical in nature. What we (geologists) do is basically reconstruct past climate data. For the present, we have instrumental data. With these inputs, computer experts can stimulate a model of how the climate will behave in the future,” she told Mongabay-India.
While Bhatt agrees that other systems can also be used to understand climate, she believes caves have an advantage. “In the caves, data ranging from a year to decades is recorded. Although a river deposits a lot of sediment that can be dated, when there is flooding or heavy rain it cuts through its own deposit and washes it away – this could mean the loss of a thousand years of data. Water turbulence also disturbs the data. In the caves, we have data that is better controlled chronologically, with a minimum margin of error of + or – 10 years. Whereas in the ecosystem of lakes or rivers, it can be between 100 and 1,000 years,” she says.
The urgent need for cave conservation
Despite their important role, Bhatt believes that India has not done enough to protect the caves with fragile ecosystems. “In northern India, caves are revered. And many people end up breaking concretions (speleothem comes from the Greek words spelaion, meaning cave; and thema, meaning deposit) and take it home for worship. If we could get people to see the science behind the caves and its fragile ecology, that would motivate local communities to conserve these caves instead of destroying them,” Bhatt told Mongabay-India.
Shirish also states that little has been done to understand the ecology of the caves and the different species that call them home. “There is no law that talks about the conservation of caves in India,” he laments. Recently, Shirish and Dhanusha Kawalkar, Senior Research Biologist, SACON, initiated an effort to conserve the Indian cave salipid in Maharashtra.
Inspired by Shirish, his mentee Kawalkar, along with other researchers, established the Speleological Association of India in September 2021, to further the understanding and conservation of caves, subterranean ecosystems and other habitats in the subcontinent. Indian.
“We are a group of nine researchers, with different interests and expertise (including geology, archaeology, bio-caving, 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 although India has been interacting with caves for centuries, studies have mainly focused on geology and cavers mostly limit their work within a state or district. “We wanted a pan-continental association that supported cave exploration, research and advocacy, an association that also addressed threats above the surface like land use change and enabled cave restoration through community initiatives,” she explains.
Pointing out that there are also many important cave systems in India from which huge rivers originate, Kawalkar says, “These underground wetlands are a major source of water.” Why then have the caves not been studied properly? “It’s their inaccessibility that is the cause,” she replies.
When native ecosystem connoisseurs become field assistants
Kawalkar recalls that his own exposure to caves was initially for spiritual purposes: “As a child, I often visited cave temples, but there was no opportunity to explore beyond that.” It wasn’t until years later, when she joined SACON who were working on the conservation of swiftlets in Andaman, that she entered the caves again. “There were almost 400 caves and I remember being a child again when I first met them. The locals who worked as field assistants with us also brought their own ethno-speleological knowledge – they guided us on where to sit, what not to touch inside a cave, the names local flora and fauna and even their characteristics,” she says.
Long before the arrival of scientists, the inhabitants were involved in the trafficking of swiftlet nests. “About 35 to 40 years ago, people used to take a torch and wait outside caves for the birds to come. The salt pans used a particular sound to locate their echoing nests and this is how the nest collectors found the salt pan colony. Until now, it is this basic technique that helps researchers like us to track colonies and estimate the size of bird populations.
With thousands of caves spread across the country, Kawalkar believes it is necessary to involve local people even in mapping cave geolocation and biological diversity. Having mapped over 100 caves (in the Andamans and Maharashtra) with Shirish, she often depends on the local community to discover more caves.
Along with the knowledge that locals bring to the table, Shirish believes that involving them is critical to the sustainability of any conservation program. “Whatever conservation we do, we do it for the local people, the ecosystem and the resources of that place. Therefore, people are major stakeholders – they should have the right and the responsibility to work for the improvement of resources and land. Kawalkar adds, “Perhaps we could declare certain areas with high density of caves as community reserves, where the community can have full rights over the management of these habitats.”
Read more: Andaman forests need longer intervals between repeated cuts to recover: study
Banner image: Kawalkar in a limestone cave in the Andamans. Photo SACON.