as we moved farther south. Straight ahead was the Sundarbans swamp, where the Ganges delta dissolves into mangrove islands and braiding channels and crocodiles and wet-footed tigers, but we weren’t going that far. Already the land was so flat and low, the water table so high, that sumps of stagnant water surrounded every village and town we passed.
Along here we started to see more date palms, their smooth trunks scarred with barber-pole striations showing where gachis had tapped them in years past. It was mid-January now and the sap harvest was on, perfect timing in case we wanted to sample a glassful. We didn’t. Bangladeshis call the stuff kajul, I learned from Arif. They believe that it’s a salubrious beverage, killing parasites in the gut. But you’ve got to drink it fresh, Arif said. Boiling the sap ruins not just its taste but also the medicinal effect. He drank it himself as a boy, yeah, sure—but not anymore, no way, not since he’s been working on Nipah.
In midevening we reached a city called Khulna, found rooms in a decent hotel, and the next day went out looking for bat roosts, of which Arif had prescouted several during an earlier trip. West of the city, the land seemed lower still, and water was plentiful—water in paddies, in sumps, in lagoons, in shrimp-raising ponds. Village people and their livestock lived on patches of dirt reached by footpath causeways, and the road itself ran along an embankment, material for which had presumably come from borrow pits that were now the funky greenish and brownish pools alongside. If you wanted high ground here, you had to build it. There were plenty of trees but nothing to call forest, just a scattering of coconut palms, bananas, papayas, tamarinds, a few hardwoods, and many more date palms, into one of which I saw a gachi climbing. He was barefoot, using his hands and feet plus a belt rope to ascend, like a Wichita lineman. He wore a lungi (a sarong, knotted at his waist), a turban, and over his shoulder a woven quiver, which held two long, curved knives. Nearby, a small boy on the roadside carried four red clay pots, empty and ready for placement to catch tonight’s drippings.
The bats would be ready too. Meanwhile they were sleeping. Flying foxes, unlike insectivorous bats and some fruit bats, do not roost in caves, mines, or old buildings. They prefer trees, from the branches of which they dangle upside down, wrapped in their wings, like the weirdest of tropical fruit. We visited four or five sites. We gazed up into treetops at aggregations of sleeping bats, talked with locals, and inspected the lay of the land beneath each roost, none of which met Epstein’s exacting standards. Either the bats were too few (a hundred here, a hundred there), the nearby trees or lack of them allowed no way to erect a net, or circumstances were wrong on the ground below. In one village, several hundred bats had established their roost in some legume trees, a tempting cluster, except that they dangled just above a big green puddle that seemed to serve as drain tank and garbage dump for the village. Lowering the net after captures would drop tangled bats into that water, Epstein foresaw, and oblige him to plunge in and untangle them before they drowned. Nope, he muttered. I’d rather take my chances with Nipah than with whatever’s in that bilge.
So we returned to a site we had spotted along the road into Khulna: a derelict storage depot within a walled compound of several acres, government-owned and once used as a repository for road-building materials. From a grassy courtyard there, among the sheds and warehouses, towered a handful of great karoi trees in which dangled four or five thousand bats. It was an especially favored roost site, evidently, because the trees were so large, the walled compound protected them from village hubbub and boys with slingshots, and each evening around dusk they could drop from their branches, take flight, circle majestically out over the Rupsha River (another branch of the deltaic Ganges), and flap away for a night’s feeding amid the villages around Khulna. Okay, Epstein decided, this is it.
Within a day, after meetings with local officials, he and Arif had obtained permission for us to go spooking around this old depot in the middle of the night. That’s why I like working in Bangladesh, Epstein said. Simple request, reasonable people, prompt action. Go into certain