Thrissur: The biggest database of echolocation calls of bats in the country has been set up in Kerala.
Kollam Munroe Island native Sreehari Raman is the master brain who worked behind this initiative. He was the young researcher who came to identify the bat varieties when the Nipa outbreak was reported in Kozhikode.
The new database will be helpful in identifying the bats in the Western Ghats in Kerala without actually catching them. An equipment called the 'bat detector' is used to record the bat’s echolocation calls. When the recorded sound is entered in the database developed by Sreehari, it detects the type of bat. During the time of Nipa, Sreehari caught the bats manually by descending into wells.
There are a total of 63 varieties of bats in the Western Ghats. Among them, only 6 are fruit-eaters while the rest are insect-eaters. As fruit-eating bats have a high sense of vision, they don’t produce ultrasonic echolocation calls. 57 varieties of insect-eating bats produce ultrasonic sounds that have a frequency between 20,000-2 lakh Hertz, which is not audible for humans.
Sreehari has recorded the echolocation calls of 42 out of the 57 insect-eating bats. He started the effort in 2016. He collected the echolocation calls of bats from deep forest areas in 30 places including Agasthyamalai, Periyar, Munnar, Silent Valley, Wayanad, Ranipuram, Senthuruni and Athirappilly.
A total of 1,400 bats were caught as part of the experiment. The bats were allowed to fly inside a tent made of net so that natural echolocation calls can be recorded. 2,070 sound waves with frequency between 20,000-1.7 lakh Hertz were recorded in this way.
Sreehari’s article was published in the journal Acta Chiropterologica, which is published from Poland. Previously, echolocation calls of bats from Himalaya was recorded in the year 2020 and this was the first of its kind achievement in the country.
