Holy Bats! – Why are Bat Populations in South Indian Temples dwindling?

It is a lesser known fact that South Indian temples apart from housing our Gods and Goddesses also house the only mammal that can achieve true flight - the bats.

Cave dwelling bats in the absence of caves find the Dravidian architecture of our south Indian temples, with its large halls, high towers and stone masonry, well suited for their roosting sites. Bats are generally found in the temple’s high ceilings, dark corners and in cracks between stones.

However, a rapid survey recently conducted by ATREE’s, Chetan Misher, Nakul Mohan Heble and Ruchi Verma in 22 temples in Kallidaikurichi, Ambasamudram, and Alwarkurichi at Tamil Nadu indicated that renovation of old temples has had an adverse impact on bat populations.

The survey indicated that measures like bat-proofing by adding nets, filling up cracks, repainting stone walls (mostly white), reconstruction of temple towers, and adding lights inside temples has had an adverse impact on bat populations.

The survey looked at seven species of bats and 37 roost sites. Three bat species, in particular, Egyptian Free-Tailed bats, Schneider's Leaf-Nosed bats and the Black Bearded Tomb bats showed a characteristic decline in population over the period 2012 to 2018.

The only exception however was the Greater False Vampire bat which while showing reduction in populations inside temples, displayed an overall trend of increasing population.

“We are unaware of the reason for this increasing population and it would require further investigation to ascertain the reason for this trend only amongst the Greater Vampire Bats,” said Chetan Misher, a PhD student at ATREE, who was part of the team that conducted the survey.

The temples surveyed were on an average 1000 years old and were built mostly during the Pandian regime (500AD-1000AD). According to the survey lesser known temples proved to be a safe haven for bats compared to those which were popular as renovation was an unlikely measure to be taken up in less well-known temples.

This dwindling population of bats in temples could have adverse impacts on areas surrounding the temples. Bats act as pollinators, aid in pest control, control mosquitoes and are responsible for the survival of certain species of trees.

This survey brings to light the threat faced by bats due to beautification drives carried out in temples.

“In order to get a detailed picture of the impact of renovation, we suggest a more robust quantitative methodology to be adapted to accurately analyze the influence of such disturbances on bat populations,” added Chetan Misher.