They were seen as bad omen, harbingers of death, companions of evil beings that would feed on the blood of unsuspecting humans. Since aeons, mankind has been wary of bats — the only mammals capable of flight — largely due to their nocturnal life and mysterious ways like hanging upside down.
In European mythology, bats were portrayed as creatures of darkness, often associated with witchcraft. The Aztecs believed bats symbolised the land of the dead. For Native Americans, they were evil tricksters. In Tanzania, bats were thought to be shape-shifting spirits that sodomise their victims.
There is no dearth of such tales, and for generations who grew up reading Dracula by Bram Stoker, bats remain blood-sucking, night-dwelling beings. Poor little creatures.
Though many now understand these ideas as mere superstition, misconceptions about bats persist — particularly following viral outbreaks such as Nipah in Kerala.
“Following the first Nipah scare, Kerala witnessed the indiscriminate culling of bats across regions,” recalls P Balakrishnan, a scientist at the Kerala Forest Research Institute (KFRI).
However, reality seldom aligns with myth. “Bats — which have existed on Earth for over 50 million years — are among the most ecologically vital yet misunderstood creatures on the planet,” he says.
Bats contribute to pollination and seed dispersal of over 500 plant species worldwide, many of which have economic and ecological value. That includes the durian fruit of Southeast Asia and the agave plant used to make tequila in South America.
Insectivorous bats consume vast numbers of pests, saving farmers billions in potential crop damage. Their guano, rich in nitrogen, phosphorus and potassium, also serves as a highly effective organic fertiliser.
To date, around 1,460 bat species have been identified globally, categorised into 21 families. India is home to 135 of these, across nine families. Kerala alone hosts 48 species (with more expected as taxonomic work progresses).
Notably, the state is home to two species listed as endangered by the International Union for Conservation of Nature (IUCN): Salim Ali’s fruit bat and Andersen’s roundleaf bat.
According to Sreehari Raman, an assistant professor at Kerala Agricultural University, 42 species found in Kerala are insectivorous. “Despite their ecological significance, studies on bats remain limited, owing to inadequate funding, lack of data, and scarce research equipment,” he says.
This issue extends beyond Kerala. Globally, bat populations are declining due to habitat destruction, deforestation, pollution, poaching, bushmeat trade and climate change. Even the rise in wind turbine usage has posed new threats.
“These pressures are particularly harmful to bats due to their low reproductive rates, social living habits and high metabolism,” explains Balakrishnan.
To raise awareness, April 17 is marked as International Bat Appreciation Day. Spearheaded by Bat Conservation International — a global organisation of scientists and researchers — the day promotes conservation efforts for the species.
A couple of weeks ago, KFRI, in collaboration with the organisation and the Conservation Leadership Programme, conducted a three-day workshop on bat classification, observation, and conservation research.
It was the third such workshop held by KFRI. The workshops train researchers in bat identification, field sampling, acoustics, telemetry, and conservation.
"These workshops are part of a broader programme aimed to address challenges like roost tree loss, zoonotic disease threats, and lack of ecological data," says Balakrishnan.
“Participants usually include researchers from across India. Over a hundred individuals from across the country have already received training through this initiative.”
Superstitions and misinformation remain a major hurdle to conservation efforts. “Public fear of bats as disease vectors has worsened,” says Sreehari, who has been studying bats for over 10 years. “Till a decade ago, people didn’t worry much about bats. Also, we didn’t hear about outbreaks at this frequency.”
So, what changed?
Many bat species are communal, roosting in the hundreds or thousands in tall trees or vast caves. Urbanisation has destroyed these habitats, as trees are felled to make way for buildings.
“And bats are very much attached to their habitats. When forced to disperse and find new shelter and food, their stress levels increase. This is what leads to the virus spreading to other species — including humans,” Sreehari explains.
Increased stress and poor nutrition lower immunity in bats, leading to viral shedding. Over 60 per cent of infectious diseases globally are zoonotic — caused by pathogens transmitted between animals and humans.
This is why KFRI has recommended a programme called ‘One Health’ — a holistic approach that extends beyond traditional medicine. “It’s an integrated strategy that includes wildlife and ecosystem health, along with human and veterinary medicine,” says Balakrishnan.
“There’s an urgent need to understand bat biology and behaviour, the effects of climate change, and how zoonotic diseases are transmitted — often without direct human contact.”
The best way to prevent pathogen spillover? Maintain ecological balance.
Sreehari also stresses how understudied bats are, from habitat and behaviour to basic species records. He and fellow researcher Nithin Divakar are currently working on a book documenting bat species in Kerala, complete with photographs and sketches from their studies.
“What started as a fascination for these flying mammals a decade ago has turned into a mission,” he smiles. “A mission to protect bats and humans.”
Trivia time
The scientific name for bats is Chiroptera. Bat behaviour varies significantly between species. Approximately 23 bat species are facing an imminent threat of extinction, 85 are endangered, 113 are considered vulnerable, and 236 are classified as data-deficient.
Some bat species live in communities numbering in the hundreds or thousands. These species are typically identified by their facial structure, nose, size, wingspan, and other physical characteristics. However, it can be challenging for the average person to distinguish between them, as many species appear similar at first glance.
Certain bats prefer to live in pairs or even solitarily. According to researcher Sreehari Raman, female bats of some species seek out separate habitats when pregnant. Once their young are old enough to fly, they return to their original habitat.
Taking wing
With research progressing, Kerala-based scientists have been able to make several international contributions too. Key among them is on Salim Ali's fruit bat, an endangered species found predominantly in the Western Ghats.
Due to deforestation and bushmeat trade, their population, which is already less than 1,000, is continuing to decline. Last week, KFRI published a paper after finding two more roosting caves of the species.
"These bats live in caves and till recently were said to only live in one roost — a cave in Mankulam in Idukki. We found two more caves of these bats, both at Vazhachal. Also, we found the presence of a lone Salim Ali fruit bat in Wayanad,” says Nithin Divakar, a researcher with KFRI.
Projects under KFRI’s department of wildlife biology:
The Fruit Bat Project: Launched in 2022, this citizen science initiative focuses on mapping roosting sites of the Indian Flying Fox (Pteropus medius), a locally threatened species linked to Nipah transmission. Over 250 roosting sites across Kerala have been mapped so far.
Participatory conservation efforts for Salim Ali’s fruit bat and Andersen’s roundleaf bat, two endangered species in the state.
Mapping of bat caves and other roosting habitats.
Taxonomic revision of cryptic and lesser-known bat species in Kerala
Research on bats of Lakshadweep and Maldives