Wildlife & Biodiversity

Unfounded fears of contagion threaten bat population in Kerala

Destruction of bat habitats and culling is rampant in Kerala despite no evidence linking the animals with disease outbreaks in the state

By K A Shaji
Published: Thursday 28 October 2021
Unfounded fear of contagion from bats threatens their population in Kerala. Photo: KA Shaji

About a fortnight ago, the residents’ associations and corporation councillor of Chelakottukara in Kerala's Thrissur district were ordered by the police to cut down six giant trees on a vacant plot. The trees constituted one of the largest bat colonies in the region.

Such a vast number of bats in the city limits poses a severe threat amid recurring cases of Nipah virus infections.

The local community obeyed, and a team of police constables helped them axe the trees and shoo away the hundreds of bats that occupied it for several decades. Newspapers praised the police for their timely intervention and removal of a ‘health hazard’.

Such incidents are not confined to Thrissur alone. In the face of repeated instances of virus appearances and continuing pandemic scares, bats have become easy targets of local bodies, police and community organisations across Kerala in the name of protecting public health. 

Giant old trees transformed into bat colonies have been axed apart from using crackers to scare away bats that live in small groups close to forests and interior areas.

TV Sajeev, a senior environmental scientist for the Kerala Forest Research Institute, said: 

Across the world, there is a tendency to link bats with bad omens and misfortunes. Here, without a shred of evidence of bats spreading Nipah and other viruses to make Kerala the virus capital of India, people are now hunting and burying bats indiscriminately apart from felling the trees which they occupy.

In Kerala, the main targets of mass culling are fruit bats. On September 5, 2021, the deadly Nipah viruses resurfaced in Kozhikode district when Kerala was already recording over 30,000 cases of the novel coronavirus disease (COVID-19) daily. 

A 12-year-old boy from Chathamangalam village, some 24 kilometres from Kozhikode city, died of Nipah and several others were hospitalised. From the beginning, bats have been projected as the carrier of the virus and the villain behind the whole mess.

"I went inside the well in the residential compound of brothers Sadik and Salih who got the Nipah infection and took out fruit bats that have been living there for a long time,” said Sreehari Raman, a well-known bat expert from Kollam in Kerala.

The samples were sent to the National Institute of Virology in Pune and other laboratories, added the scientist who is currently studying them at the Beijing-based Chinese Institute of Sciences.

“Bat samples have also been collected from across Kozhikode district and subjected to intense analysis. Bat movements have been monitored,” he said. 

The process was renewed after the second Nipah outbreak in the state, Raman added. “So far, the scientific community has failed to find any link between the two Nipah outbreaks and the presence of bats in the localities.”

The Nipah sources are still unknown, the expert said. 

Mass culling of bats occurred across Kerala after the Perambra and Chathamangalam outbreaks of Nipah, according to him. However, the government assured that it had contained the spread, and more scientific studies are needed to establish the link between bats and viruses.

In state capital Thiruvananthapuram, a significant bat colony was located close to the zonal office of State Bank of India at South Fort. It had hundreds of bats and the colony was destroyed earlier this month by the city municipal corporation citing Nipah scare. 

So far, no Nipah case was reported either from Thiruvananthapuram or from the entire southern region of Kerala.

"We used to click pictures of numerous bats occupying the trees at South Fort. Now such trees are hardly anywhere in sight,” said Rajan Robert, a retired bank official and nature photographer.

Poachers and other people with vested interests are citing the Nipah virus as an excuse to hunt bats, he added. “Sadly, local authorities and police are falling prey to their traps.” 

Instances of disease spreading from bats to people are not frequent, said Dr NM Arun, public health activist and virology expert. He added: 

Bats are revered for their help in agriculture in districts like Palakkad, Thrissur, Ernakulam and Idukki. But the demand to get rid of them is getting a new dimension in the backdrop of the pandemic. 

More studies on animal hosts that function as transmission pathways between viruses and humans are needed, Arun added. “Bat hunting in Kerala is undiscriminating and devoid of any logic.” 

There are 128 species of bats across India. But there is very little information on their population and the areas each variety occupies. 

Studies on their capability to spread zoonotic diseases are only at a primary stage at present. Many of them are endangered and demand immediate conservation.

Across the world, there are certain recent attempts to project bats as carriers of diseases. They were accused of spreading Severe Acute Respiratory Syndrome (SARS) in China, Middle East respiratory syndrome coronavirus in Saudi Arabia and Ebola in Africa.

Kerala has a long history of preserving bats with wings like birds and furry faces similar to mouses, Sajeev shared. “They flit giddily like moths during nights and that has won the admiration of children.”

In Kerala, the main targets of the present hunt are three varieties of fruit bats: The Indian flying fox, Salim Ali's fruit bat and fulvous fruit bat. 

The Indian flying fox are commonly seen in big numbers on tall trees. Salim Ali's fruit bat is endemic to the rainforest pockets of the Western Ghats. The fulvous fruit bat is often found in caves, wells and tunnels. 

The third species was accused of spreading Nipah in Perambra and the Indian flying foxes of causing the Chathamangalam outbreak.

Sreehari, who is now in the process of preparing India's most extensive database on bats, said:

In general, fruit bats are important pollinators and seed dispersers. In the case of insectivorous bats, they are helping farmers in controlling insects.

Bats provide tremendous ecological as well as economical services, he added. Habitat loss of bats is rapid in India and this poses a threat to their population. They also die after flying into wind turbines. 

Removing bat colonies by axing trees would not yield desired results as the bats would find alternative trees, experts noted. 

Every species harbours viruses that are potentially risky to other species, said Sreehari. “If all bats carried pandemic viruses, the human population of the country would have already been wiped out.” 

Some of the most valued crops are dependent on flying foxes and their closest relatives for pollination, he added. “In the case of flying foxes, they are southeast Asia's most important long-distance seed dispersers that are essential for reforestation.

It is sad that an unnecessary panic has spread among the people against bats, PO Nameer of Kerala Forestry College in Thrissur said.

Bats have been living close to forests for ages. Most older open wells in the state, especially those with laterite rock beds, commonly have bats hanging on the walls, he added. 

Cleaning all wells and removing bats are not necessary, Nameer opined. “Instead, let us use boiled water for drinking and cooking.”.

Any virus present in bats, moreover, will get more virulent if they lose their habitats, according to experts. After losing their colonies, bats would turn stressed and hungry, resulting in their immune system weakening. Then the virus levels in them go up, along with the chances of viruses spilling out through their urine and saliva.

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