We had veered from the main river long ago, choosing a mind-numbing series of tributaries, each more narrow than the last. All of them looked the same to me: just brown water creeks walled in by chattering green jungle. Ferns unfurled toward us; flesh-eating flowers oozed their oils in the sun, luring insects to sticky deaths. Orchids steamed like giant dozing ears in the boughs of trees. Every now and then we’d all sprawl facedown or flat on our backs in the boats to pass under fallen trees that hovered just feet from the surface, or skid over logs, propeller yanked from the water. We plunged deeper and deeper into the green.

“You smell them?” Omar said under his breath to Franz and the three other hunters in our boat. “Maybe thirty, forty.”

We had been tracking a herd of white-lipped peccary since early that morning. Franz squinted up into hulking branches above us, on constant lookout for snakes lounging there. We drifted in the narrowest channel yet—just five feet across—its water black with sediment but glowing an eerie gold where the sun filtered through.

I sat behind Omar, revolver tucked into a holster looped over my belt. Franz and the other men sat behind me. It was a position I’d fought bitterly for, to sit in the hunting canoe with the rest of the men. At five months pregnant, I felt strong. I wore a dress I had pieced and sewn together from two rice sacks, complete with sleeves to help protect myself from the bugs.

A boat carrying three women and five dogs kept nose to stern behind us. The women watched me with blank, hard faces: all three were older, maybe in their forties, with grown children. Unlike the younger women, these three had never warmed to me anyway, so I didn’t take to heart what I read as resentment for traveling and hunting with the men.

We swung around a hairpin curve; the creek joined another, widening into a pond. Six eight-foot black caiman basked on the far bank, sunning themselves. One of them lay with its head in the water, mouth open wide as if to eat anything that might float by; along the row of ceramic-green bumps on its snout a handful of bright orange butterflies balanced, fluttering delicately. At our approach, the biggest one rose on its short legs. Carrying its belly just clear of the ground, it hurtled headlong and with a thrash of its armored tail it disappeared, leaving a soft swirl of bubbles on the water. Every log was a caiman unless it proved itself otherwise.

Omar stood as he gondola-ed us to the opposite beach; the other canoe followed swiftly behind. Dozens of Morpho butterflies—each as big as a child’s hand—danced along the bank, turquoise-and-black wings glowing like stained glass. Our boats nosing onto shore spun them into brilliant blue vortexes before they settled on the sand just yards away. The dogs leapt from the boat, eager to be free from its confines, but wary of the snapping jungle, sniffing at the ground and keening at our sides. The men mumbled excitedly to one another; there was an electricity among them. The water smelled putrescent, steaming with its myriad biological transactions; beyond us, the forest shimmered with midday heat.