Late evening at Bengaluru’s Sankey Tank is a spectacular visual experience, dusk-kissed skies turning the lake’s water molten while the park’s other regulars — amblers, brisk walkers, couples in love, runners, cormorants, ducks and red slider turtles (pets-turned-invaders) — slowly recede into the darkness. It is also when flying foxes, who have been roosting on the trees bordering this man-made lake, named after the man who built it in 1882 to meet the city’s water supply needs, wake up.

Roundglass Sustain’s recently-released film Batman and the Baavali, a documentary that showcases the nocturnal world of bats with bat conservationist Rohit Chakravarty, captures this stunning moment: swathes of these fruit bats flying across the park at dusk, silhouetted against the darkening skies, some even dipping down to skim the surface of the lake to hydrate themselves.

“They go down to the water…make a splash with their chest…head off to the nearest tree…and drink water from the wet fur,” explains Rohit, in the film. “And all of this is happening bang in the middle of a city.”

Rohit, whose work with bats often take him to remote, far-flung places, says spotting these flying foxes in the heart of the city was one of his most satisfying moments. “While I would have expected bats to be there, I didn’t go looking for them,” he says, pointing out that almost every city in India has bats, but we simply do not notice them. “Bats are in places where you would least expect them, and there are many such places in Bengaluru.”