The great rivers that flow down from the mountains of the Western Ghats have bestowed upon southern India’s Tamil Nadu state a rich cultural heritage and a thriving, rice-based agriculture. Imposing Hindu temples rose 500 to 1,000 years ago alongside such rivers as the Cauvery, Vaigai and Thamirabarani. The farms and cities grew, and the habitats of bats and other wildlife disappeared in their wake. As decades passed, some bat colonies found desperately needed sanctuary in dark recesses of the ancient temples.
Now the bats of these temples, among their last refuges in a human-dominated landscape, are under threat as the surrounding old-growth trees where fruit-eating bats forage are removed, the temple towers are modernized and lighting is installed into once-dark spaces. One recent temple renovation displaced some 10,000 fruit bats (apparently Rousettus leschenaultii). None of them returned.
Although bats are known to live in many of the temples, until the Ashoka Trust for Research in Ecology and the Environment (ATREE) began this project, there were no detailed records of the species and numbers of bats roosting in structures.
With support from a BCI Global Grassroots Conservation Fund grant, we surveyed 61 temples for bat use and confirmed bat roosts in 31 of them. We identified five temple-roosting species and documented the architectural characteristics that seem to attract bat populations. We also trained local college students in bat research and monitoring while educating schoolchildren and residents about the benefits of bats. We also began meetings with temple authorities to help them conserve the invaluable flying mammals.
Given the importance of farming in the region, the economic value of insect-eating bats could be very significant. Some temple bat species also deliver such ecosystem services as pollination and seed dispersal, as well as providing free fertilizer with their droppings. Yet local people know almost nothing about their bats, which are widely considered vermin and are routinely persecuted.
Working along the Thamirabarani River, we first trained students from Tamil Nadu Agriculture University to safely capture bats in mist nets and identify species. We hope they will also provide the core of a community of bat watchers who will help monitor and protect these bats in the future.
Each of the 61 temples we visited was precisely mapped. When bats were present, we set our mist nets and captured some of them for species identification, then released them in the same spot. We also located roosting sites within the temples to document preferred conditions.
At the 31 temples where bat use was confirmed, we identified a total of 4,116 bats of five species, all but one of them insectivorous. The fruit-eating Leschenault’s rousette (Rousettus leschenaultii) was the exception. By far the most common, with 1,920 sightings, was Schneider’s leaf-nosed bat (Hipposideros speoris), a species that is often hunted for food and folk medicine. The other temple-roosting species are the greater false vampire bat (Megaderma lyra); the Egyptian free-tailed bat (Tadarida aegyptiaca); and the black-bearded tomb bat (Taphozous melanopogon), which sometimes eats fruit as well as insects.
Meanwhile, we developed educational materials and presented educational programs for about 200 students at two schools in the area. We organized bat-appreciation projects during last October’s Wildlife Week in India. Bat-drawing competitions proved especially popular and prizes were awarded for the best artwork.
Also during Wildlife Week, we conducted a “procession” campaign at Padmaneri, where several bat-roosting temples and trees are found. Around 500 students from the village’s Government High School participated in the parade-like event, carrying placards and voicing conservation slogans.
Our project clearly highlighted the importance of these ancient temples as roosting sites – sometimes as the last available sanctuary – for the beneficial bats of Tamil Nadu. Key elements of temple architecture, especially the availability of relatively undisturbed dark corners and rooms, are critical for maintaining these populations and the ecosystem services they provide.
Yet many of these old temples are being renovated, usually to the detriment of the bats that roost there. The modernized temples typically illuminate once-dark corners and create high-decibel noise on a daily basis. In meetings with temple officials, we described and identified the roosting bats and their value to local farmers. Obviously, we cannot prevent the renovations, but we are working to minimize their impact on bat colonies.
We find that some temple authorities are capturing the bats and releasing them in the forests. We hope to provide bat houses or other artificial roosts for bats that are displaced by renovations. After our meetings, many officials enthusiastically supported the use of bat houses in their temples.
As is so often the case for bat conservation around the world, education is the key to protecting India’s temple bats. Educating people about the economic and ecological value of bats gives them a reason to conserve the flying mammals they have disdained for generations.
We hope to continue our education efforts and to more fully research and report on the true value of the temple bats and their most critical conservation needs.
M. MATHIVANAN is Field Coordinator for the Agasthyamalai Community?based Conservation Centre in Tamil Nadu, which is part of the Ashoka Trust for Research in Ecology and the Environment.