MUNSHIGANJ, BANGLADESHWhen Rafikul Mali became a pirate in the Sundarbans, he knew he was in for a rough and uncomfortable ride. He’d braced himself for repeated run-ins with fist-size spiders and some of the two-dozen species of snakes that slither through the mangrove forests skirting much of Bangladesh’s coast and extending into India. He’d even prepped for a relentless cat-and-mouse game with security forces, who have often tried—and just as often failed—to dislodge pirate gangs from their jungle redoubts.

The menace that neither he nor his fellow pirates had accounted for, though, was the one that quickly came to dominate their imaginations: the Bengal tiger. Some nights, the men lay awake, firing their rifles at rustlings in the undergrowth. On others, when