Blood-sucking vampires. Ugly-looking rodents. Reservoirs for viruses and diseases. It is quite an understatement when one says that bats have a bad rap among us humans. The pandemic also saw them wrongly take the blame as reservoirs for the SARS-CoV-2 virus that causes COVID-19. But as they became a household topic for all the wrong reasons, it provoked the scientific community to finally sit up and push back against the misinformation and paranoia. Today, the internet is flush with stories that dispel myths and answer queries about bats and the coronavirus and tell us why bats should not be feared in general.

On the special occasion of International Bat Appreciation Day, which falls on April 17, we talk to Rohit Chakravarty, a chiropterologist currently pursuing his PhD at the Leibniz Institute for Zoo and Wildlife Research in Germany. For his doctoral thesis, Rohit is studying the functional and phylogenetic diversity of bats across elevations in the Himalayas.

Read on to learn mind-blowing facts about bats, how to identify bats by their calls, a quick bat watching tutorial and more.

Rohit Chakravarty bat scientist with a bat detector
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"So for people to be able to identify bats and for them to form a connection with the bats, the best way is to record bat calls using an ultrasound recorder called bat detector." Photograph: Rajesh Puttaswamaiah

It is International Bat Appreciation Day, after all! What is the one fact about bats that blows your mind?

Definitely, their ability to echolocate! At night, when we step outside our homes, there is so much going on above our heads that we are unaware of just because it is happening in ultrasound. Other animals also make similar use of sound, but nobody does it as fast as bats can. When an insectivorous bat is hunting an insect, it happens at lightning-fast speeds.

Another cool fact about bats is that they are among the few animals that use oral sex. Somewhere around 2010 was when they first found evidence of female-to-male oral sex in the Short-nosed Fruit Bat (a common bat seen in India). But when people started looking for this in other fruit bats, for example, the Indian Flying Fox, it went in every direction. There is male-to-female, female-to-male, and male-to-male oral sex. There are hypotheses that it improves sperm motility where female-to-male oral sex is concerned, but none of these have been tested. For all you know, they could be doing it for pleasure. Which is, of course, the hardest to quantify because how are you going to do that?

Another would be their longevity. Some small bats that can fit in your palm and weigh 5-10g can live up to 20 years (the current world record is 41 years)! They have a much longer lifespan than that of a 100kg tiger!

Kashmir Long eared Bat
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India is home to close to 130 different species of bats. Kashmir Long-eared Bat. Photograph: Rohit Chakravarty

Bat watching doesn't sound that different from birdwatching. But that couldn't be further from the truth. Could you give us a quick bat watching tutorial?

I would actually split bat watching into two categories. The first category is a beginner-level bat watching experience, and the second is an advanced-level bat watching experience. They are two very different experiences. While the beginner level is accessible to almost anybody, the advanced level, unfortunately, is restricted to scientists who have the permits and funding to go out and catch bats in the field. For a beginner-level experience, you can visit a cave, fort or any abandoned place in your vicinity, and you will be able to see different species of bats. The important thing you need to remember is that this kind of bat watching happens during the day. You need to be more careful and more respectful towards the animal because it will be sleeping at the time and keep disturbance to a minimum. You don't even need to go to caves. You are bound to have a colony of flying foxes in your city somewhere. When you start exploring caves and forts, you will get exposed to another five or six species found in your city, depending on where you are. For example, if you live in a city like Hyderabad, there is a large colony of about ten thousand Fulvous Fruit Bats living inside Golconda Fort, right in the middle of this urban jungle. Then there are bats like tomb bats and mouse-tailed bats, which you can see easily. This is the kind of bat watching anybody can do, provided they keep the disturbance at a minimum. Advanced-level bat watching is much more intrusive, where you are actually putting out nets to catch bats. This way you are seeing more diversity, species that you rarely find inside caves.

Scientists setting up a bat net to catch and study bats
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"Advanced-level bat watching is much more intrusive, where you are actually putting out nets to catch bats." Photograph: Farah Ishtiaq

You are building an Indian bat call library. Why? More importantly, how? Bat calls are imperceptible to humans, right?

In India, most people tend to think that there are only two kinds of bats, there is one flying fox and anything that small is a pipistrelle. We don't realise that the small bats flying over our heads are actually two or three different species, and sometimes they are not even pipistrelles. Bats, like many other animals in the world, can be identified by their calls. So for people to be able to identify bats and for them to form a connection with the bats, the best way is to record bat calls using an ultrasound recorder called bat detector.

Firstly, bat recorders are not the cheapest piece of equipment out there. They are becoming more affordable because the demand is increasing, but at the moment, a decent bat recorder can cost about ₹25,000. Even with that, if a person has recorded bat calls, where is the database telling them how to identify it? That's what I'm trying to do. When I started my project in Uttarakhand in 2016, it was to survey bats in the region. I was just looking around for different species in different parts of Uttarakhand, but at the same time, I was also recording their calls. Then I started doing the same in different parts of the country, and in the end, I had recorded calls from about 55 species of bats, which is roughly 45 per cent of the bat diversity in India (we have close to 130 species of bats). The first point of the effort was for education and outreach so that people can watch bats in a better way. As much as it helps people, it also helps scientists like myself, say if I want to do some kind of long-term monitoring of bats in a particular region, I can't keep going there again and again and surveying the same area, it costs a lot of time and money. A simpler workaround would be to install bat detectors that can be deployed in the field like camera traps, and they record the calls night after night.

Apart from helping in identifying the species that is calling, bat recorders also give a glimpse as to what they might be doing. When a bat is calling, it can be for multiple reasons, to navigate or hunt insects. When a bat calls, on a bat detector, it sounds somewhat like a 'tic-tic-tic', and when a bat is trying to find an insect, it goes 'tic---tic---tic', and when it gets a signal from an insect, it has to increase the rate at which it calls, so sometimes the call goes from 'tic-tic-tic' to 'trrrrrr', which is when the bat is actually trying to hunt an insect. So it is basically a way to see your world through sound. Fruit bats do not echolocate, those you always have to see, but insect-eating bats, which make up 80-90 per cent of the diversity in India, can be identified to a fair degree by their calls.

What do you think is the future of bats and bat research in a post-covid world?

I am not the most optimistic person, but I do feel that, after the pandemic, bats are finally getting some kind of appreciation that they deserve. Of course, you know, when it started there was a lot of panic, people were genuinely scared of bats. But think of it as maybe Will Smith hitting Chris Rock at the Oscars, any kind of publicity works in favour of celebrities. That is what happened with bats, these were animals that were maligned up until now, after the pandemic they became a household topic for all the wrong reasons, but that also motivated a lot of scientists to start putting their perspectives out in the media. It was high time that scientists did that and that was finally happening. Now if you google ‘bats and covid’ you’ll find plenty of articles describing why bats are not to blame for the pandemic and why they should not be feared in general. So I feel that we used the pandemic to finally give bats the recognition that they deserve.

Bat researcher Rohit Chakravarty studying bats in the field
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Rohit has recorded calls from about 55 species of bats, which is roughly 45 per cent of the bat diversity in India. Photograph: Emily Stanford

What have been your learnings so far from your efforts to generate public awareness about bats in India?

I really like public speaking and I like talking to an audience. I had always wanted to do some kind of outreach, and I had been doing it at a small scale. But when the pandemic happened, I felt that this was a time that demanded a scientist to take the baton and explain the nuances of the situation to the general public. The thing that I realised was, in such a situation, we need to see a face talking to the public rather than the media shouting curses at bats and spreading all kinds of misinformation on print. It helps when you see a person talking to you in a friendly or polite manner and trying to explain things to you. I really wanted to try and be that person talking to the people. The first thing we did was a press release, with all the bad information floating in the media, we needed to realign that medium. After doing the press release, we realised that the English dailies had picked it up quickly, but that was not enough and we started translating and putting it in local newspapers. Following that podcasts happened, webinars, of course, that was the time when webinars were at their peak.

Bat researchers studying bats in caves
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Catching and handling of bats should be attempted only if you are trained to do so or if you are under professional guidance. Photograph: Dr Balaji Chattopadhyay

To speak about my future, I would definitely try to keep some kind of bat education and outreach going on in my life. And, this is something that strikes me about International Bat Appreciation Day, for every other animal, you have something like International Tiger Day, World Turtle Day etc., but here the emphasis is on appreciation. Because everybody realises that the biggest conservation threat that bats face is a lack of appreciation and that is what we are trying to move towards.