This story appears in the June 2016 issue of National Geographic magazine.

Elias Machipango Shuverireni picks up his long, palm-wood bow and his arrows tipped with sharpened bamboo. We’re going monkey hunting in Peru’s Manú National Park—a huge swath of protected rain forest and one of the most biodiverse parks in the world.

The hunt is legal. Elias belongs to an indigenous group called the Matsigenka, of whom fewer than a thousand live in the park, mostly along the banks of the Manú River and its tributaries. All the park’s indigenous inhabitants—so-called uncontacted tribes as well as the Matsigenka—have the right to harvest plants and animals for their own use, but they can’t sell park resources without special permission, and they can’t hunt with guns. Elias and his wife—people in Manú go by first names—grow yucca, cotton, and other crops in a small clearing on the Yomibato River. Their children gather fruit and medicinal plants. Elias catches fish and fells trees. And he hunts, especially spider monkeys and woolly monkeys—favorite foods of the Matsigenka. Both are threatened species.

Things have been this way for a long time, but the Matsigenka are growing in number, which worries some biologists who love the park. What if their population doubles? What if they start using guns? Could the monkey populations survive? And without those species, which disperse the seeds of fruit trees as they snack through the jungle, how would the forest change?

As the forest outside the park becomes increasingly fragmented by natural gas extraction, mining, and logging, protection of the park becomes more crucial. So does this question: Are the people who live inside it good for it or bad? And is the park good for them?

View Images Two women from the “uncontacted” Mashco-Piro tribe watch the photographer’s boat pass on the Alto Madre de Dios River. A century after their settled forebears likely fled into the forest to avoid enslavement by rubber barons, a small group has begun appearing on the riverbank.

Elias, 53, has curly black hair and an intense gaze. He’s wearing a green soccer jersey, shorts, and sandals made from old tires. His home is a clearing with several open, palm-thatched buildings. As we cross his fields and plunge into the jungle on a muggy day last November, we’re accompanied by his son-in-law Martin, his daughter Thalia, and a teenage granddaughter. Like Elias, Martin is armed with a bow and arrows. Thalia wears a handwoven sling to carry back plants. I’ve got Glenn Shepard, an anthropologist who has spent 30 years working and living among the Matsigenka and is one of the few outsiders fully fluent in their language.

Five minutes into the jungle we hear the calls of dusky titi monkeys. The hunters don’t break stride; titi monkeys are target practice for teenagers. Another five minutes and we hear a troop of capuchin monkeys. Elias pauses, even raises his bow, but lets them go. He’s holding out for something more poshini—that is, delicious. We begin a tour of fruit trees and soon find several with recently dropped fruit. Monkeys have been here, but they’re gone. Another hour goes by. At last Thalia’s face lights up. Osheto, she says in a whisper—spider monkeys.

Now we see them, leaping at high speed through the crowded treetops, 60 to 100 feet above our heads. The hunt is on—and I, for one, am stumbling over roots, crashing through vines, slipping in mud, and running into thorns and spiderwebs while watching for snakes. Elias and his family are more graceful, but this jungle is difficult even for them. Hunting animals on the ground—fat peccaries, say—is tough enough. To bag a spider monkey, a Matsigenka hunter first has to catch up with it, then shoot more than six stories straight up at an erratically moving target.

He has several natural medicines to improve his chances. A day or so before a hunt he’ll often drink ayahuasca, a potent, psychoactive mix that makes him vomit. It’s supposed to purge him of harmful spiritual influences and put him in contact with the spirits that control his quarry. To sharpen his aim, he may squeeze a plant’s juice into his eyes. During the hunt itself, he may chew some sedges, or piri-piri, that harbor a psychoactive, mind-focusing fungus. Shepard, who has tried them, calls them jungle Ritalin.

But none of these performance enhancers guarantee success. We follow Thalia’s signals as the dark, long-limbed shapes flit away far above us. Elias bounds ahead, catches up with a female, takes aim, and looses an arrow. He misses. The monkeys bolt. There’s no chance for a second shot. If he’d had a shotgun, the monkey would have been dead.

View Images Clay cliffs just outside Manú National Park form a natural salt lick that attracts various animals, including these red-and-green macaws. More than a thousand species of birds—10 percent of the world total—live in and around the park.

No guns, no roads, no buying or selling: There may be people in Manú, but it feels far, far away. The most popular route to the park involves a 10-hour ride down the Andes on a hair-raising road, followed by five hours in a motorized canoe on the Alto Madre de Dios River to its confluence with the Manú River. The main park entrance is near there, but to visit Elias’s village and others—which requires permission from the Peruvian government—Shepard and I had to motor for several more days up the Manú and its tributaries. The remoteness has protected the park from loggers and miners, and also from tourists. A few thousand at most visit each year.

Peru MANÚ N.P. SOUTH AMERICA Species Fewer Many Matthew W. Chwastyk, NG STAFF SOURCE: Matt Finer, Monitoring of the Andean Amazon Project

At 6,627 square miles, the park covers the entire watershed of the Manú River, from grasslands at nearly 13,000 feet, on the eastern flank of the Andes, down through moss-draped cloud forest to the lowland rain forest of the westernmost Amazon Basin. It’s a sumptuous, extravagant, overwhelming landscape. The region is traversed by tapirs, crowned by flights of scarlet macaws, veined with snakes. Ninety-two species of bats own the night sky; 14 species of primates swing through the trees, pursued by harpy eagles with six-and-a-half-foot wingspans. Butterflies are everywhere: scarlet knights; giant blue morphos; tiny, transparent glasswings. And on every surface, vertical and horizontal, there are ants. At night the foliage sparkles in your headlamp with what looks like pixie dust—the shining eyes of hundreds of thousands of insects.

There are a thousand tree species of all sizes, many of them woven together with thick lianas. Among the most ecologically important are figs. Because they fruit all year long, they sustain many animals through the dry season.

“I’ve seen a hundred monkeys in a single tree,” says Duke University ecologist John Terborgh. “On moonlit nights, if they’re hungry, they’ll get up at two in the morning and be there at 4 a.m.” Terborgh and his colleagues took over the Cocha Cashu Biological Station soon after the park was established in 1973. The research area covers less than one percent of the park but harbors 70 species of nonflying mammals and more than 500 species of birds.

“Manú is one of the few places in the tropics where there is an opportunity to experience and study biodiversity in its full glory,” says Kent Redford, an ecologist at Archipelago Consulting in Portland, Maine. “It is an extraordinary flowering, relatively little impacted by the human hand.”

Rich as it is, Manú isn’t an untouched Eden. There’s plenty of history here. Many tribes speaking multiple languages lived along the Manú River’s banks, so highly populated that one tribe called it the River of Houses. Inca and then Spanish conquistadores, facing the impenetrable forest and skilled warriors, failed to subjugate the settled tribes. But trading with the Inca connected them to the wider region. And Spanish diseases, which killed untold numbers, began connecting the region to the wider world.

In the 1890s this world was again turned upside down. Rubber for tires was selling at get-rich-quick prices. Rubber barons hired Amazonian natives to tap trees and also to raid other tribes for slave labor. One ambitious baron, Carlos Fermín Fitzcarrald, got more than a thousand people, mostly members of the Piro tribe—relatives of the Mashco-Piro who lived along the Manú—to carry a riverboat piece by piece over the isthmus separating that river from the upper Mishahua. His arrival opened up the Manú Basin to rubber tapping.

With Piro as his troops, Fitzcarrald tried to enslave the tribes along the Manú. Hundreds died resisting him; the river is said to have flowed red. Another tribe, the Toyeri, was almost wiped out. Some Mashco-Piro died, and others are thought to have fled into the forest. It’s their descendants who’ve made news lately by coming out of the forest and seeking contact.

View Images The Alto Madre de Dios flows along the southern boundary of Manú Park. To enter the park, visitors typically take a motorized canoe downstream for five hours—longer if the water is low—then continue upstream on the Manú River.

In short, the political geography of Manú is neither primeval nor isolated. It has been buffeted for more than a century by the forces of a globalized economy, in which technological innovation and consumer demand in one part of the world shape—and often damage—the lives of those who live near valuable natural resources.

After the rubber boom collapsed, most of the Piro—who are now often called Yine, after their language—moved down the Manú River, eventually establishing villages such as Boca Manú and Diamante on the Alto Madre de Dios River. Into the void stepped the Matsigenka. They moved in from the west and south, first to the remote headwaters, then eventually to the vacated Manú riverfront, after missionary schools were established there in the 1960s.

In communities such as Tayakome and Yomibato the Matsigenka now have not only schools but also medical clinics and communal satellite phones. The charity Rainforest Flow recently installed sanitation and water-treatment systems that deliver clean water to nearly every household. People in these sprawling settlements—from one house you generally can’t see the next—hunt, gather, and grow their own food. But they also play Peruvian pop on boom boxes and wear knockoff Crocs and T-shirts that say things like “Palm Beach,” along with their traditional clothes. The Matsigenka who live near the headwaters still wear hand-spun cloth and get by without money or metal tools. Over time they’ve been trickling into the riverfront villages, looking for axes and medical care.

View Images A pet saddleback tamarin hangs on tight to Yoina Mameria Nontsotega as the Matsigenka girl takes a dip in the Yomibato River, deep inside Manú National Park. (Learn more about the girl in this photo.)

The Mashco-Piro are more isolated still. Since the rubber days they’ve kept to themselves, hunting and gathering deep in the forest. But they’ve likely been well aware of the outside world, and in the past five years members of one group have begun appearing on the beaches of the Alto Madre de Dios, just outside the park, beckoning to boats and gesturing for food. They may have been driven out by the intrusions of mining, natural gas, and logging industries or by a recent decline of the peccaries, which are a major food source.

Tourists and local people have given things to them, sometimes with tragic results. In 2011 some Mashco-Piro killed Nicolas “Shaco” Flores, a Matsigenka man who’d given them tools and food for years. In 2015 they killed a young man in the village of Shipetiari.

Romel Ponciano is one of several Yine from villages like Diamante who work for the Peruvian Culture Ministry trying to build friendly relations with their isolated kin. He and the others staff a post on the Alto Madre de Dios, across from a riverbank where a group of Mashco-Piro has often appeared.

The riverfront post is named Nomole, “brothers” in Yine. Still, Romel’s initial contacts with the isolated group were stressful. They asked him to shoot an arrow and take off his clothes. They stared into his eyes and mouth, smelled his armpit, felt his testicles—all to find out whether he really was a brother. Romel has since warmed to them—they nicknamed him Yotlu, meaning “little river otter”—but he never turns his back on them. “Maybe in five or 10 years they will walk around like us,” he says. “They will still have their arrows for hunting, but not for killing. They kill because they are afraid.”

View Images A camera trap caught this ocelot on a nighttime prowl. Ocelots weigh up to 33 pounds; their diet includes rodents, lizards, sloths—and also his chickens, says hunter and farmer Elias Machipango Shuverireni. Still, he admires the cats’ beauty.

Doctors who’ve examined the Mashco-Piro say that so far their isolation has kept them healthier than local settled indigenous people, who struggle with respiratory infections and dental bacteria transmitted by outsiders that can leave them coughing and toothless. But the Mashco-Piro’s isolation also means they have little or no immunity, so viral diseases like measles and yellow fever could easily kill them.

As we round a river bend on the way to Nomole, I catch a glimpse of moving figures on the far shore. We’re too far away to make out faces, but we can see their naked, sienna brown bodies against the beach of gray river rocks. They have a fire going, and white smoke billows upward. For our safety and theirs, to protect them from disease, we don’t seek to make contact.

Under the wide blue sky, surrounded by seemingly endless jungle, it’s easy to imagine we’re watching people untainted by civilization, living in primeval bliss. I have to remind myself that they’re more like refugees from genocide. Traumatized unto the fifth and sixth generation by the rubber boom, living as hunter-gatherers where their forebears had farmed, they’re not uncontacted at all. They were contacted in the 1890s, plenty.

View Images The giant otter grows up to six feet long and eats up to eight pounds of fish a day. Once common in South American lakes and rivers, playing in noisy families, it’s now endangered in most areas. But the population in Manú has risen since commercial hunting was banned in 1973.

The devastating rubber boom was followed by other resource booms. Timber, gold, natural gas—all are being wrested from the forest by poorly paid locals. They then rise in price as they make their way through middlemen to trade centers in the Andes. Aside from some small-scale illegal logging inside the park, Manú remains a dark green exception in this landscape of extraction.

Just outside the park’s northwestern boundary, pipelines carry the output from the rich Camisea fields, which produce up to 1.2 billion cubic feet of natural gas a day and contribute enormously to Peru’s economy. Recent exploration to the southeast could tempt Peru to run a pipeline through the park to connect with the Camisea lines. David Hill of the Guardian, who has reported from the region for years, says one company, Pluspetrol, is interested in exploring inside the park. Whether the Manú Basin becomes an oil and gas center, Hill says, “depends on Peruvian and international civil society. It depends on the Matsigenka and the Yine.”

Amazon River drainage basin Peru MANÚ N.P. SOUTH AMERICA NGM MAPS Threatened Haven Manú National Park protects grass­lands, mountainous cloud forests, and tropical lowland rain forests. It’s one of Earth’s most biodiverse places. Reserves and other buffer zones surround the park but can’t completely protect its natural riches, which include more than a thousand species of birds and nearly 290 species of reptiles and amphibians. Manú is threatened from the outside by enterprises eager to exploit its minerals, timber, and, potentially, natural gas. Some researchers argue that the park may also be threatened from the inside, by growing numbers of indigenous people, including isolated tribes, who engage in subsistence logging and hunting. ALTO PURÚS NATIONAL PARK Sepahua ALTO PURÚS NATIONAL PARK Lot 57 UCAYALI Note or units or whatever CUSCO Serjali (Yora or Nahua) UCAYALI Amazon River drainage basin SOUTH AMERICA Peru CUSCO KUGAPAKORI-NAHUA-NANTI TERRITORIAL RESERVE Serjali (Yora or Nahua) Area Enlarged SOUTH AMERICA Tayakome (Matsigenka) KUGAPAKORI-NAHUA-NANTI TERRITORIAL RESERVE Sarigemini (Matsigenka) Lot 56 Tayakome (Matsigenka) Lot 88 Sarigemini (Matsigenka) Cocha Cashu Biological Station Marankeato (Matsigenka) Camisea Yomibato (Matsigenka) Lot 58 (Gas block under exploration) MADRE DE DIOS TERRITORIAL RESERVE (Mashco-Piro) Maizal (Matsigenka) Fitzcarrald MANÚ NATIONAL PARK Cocha Cashu Biological Station Marankeato (Matsigenka) Yomibato (Matsigenka) Lot 58 (Gas block under exploration) 1,129 ft 344 m Sotileja (Matsigenka) MADRE DE DIOS TERRITORIAL RESERVE (Mashco-Piro) Montetoni (Matsigenka) 10 mi MANÚ NATIONAL PARK Source of the Manú River 1,129 ft 344 m Sotileja (Matsigenka) 10 km Cumerjali (Matsigenka) ISLA DE LOS VALLES (Yine or Piro) MACHIGUENGA COMMUNAL RESERVE Source of the Manú River Boca Manú Cumerjali (Matsigenka) Diamante (Yine or Piro) MEGANTONI NATIONAL SANCTUARY ISLA DE LOS VALLES (Yine or Piro) MACHIGUENGA COMMUNAL RESERVE PUERTO AZUL (Amarakaeri) Boca Manú Diamante (Yine or Piro) MEGANTONI NATIONAL SANCTUARY Nomole Post PUERTO AZUL (Amarakaeri) Shipetiari (Matsigenka) BOCA ISIRIWE Nomole Post Palotoa (Matsigenka) Park boundary Shipetiari (Matsigenka) Chancamayo Gas block under exploration Itahuanía BOCA ISIRIWE Mameria (Matsigenka) Shintuya (Amarakaeri) Shintuya Palotoa (Matsigenka) Callanga (Quechua) Chancamayo Gas block under exploration Itahuanía Boca Colorado Shintuya (Amarakaeri) San José de Karene PUERTO LUZ (Amarakaeri) AMARAKAERI COMMUNAL RESERVE Shintuya Salvación Callanga (Quechua) Santa Rosa de Huacaria Pillcopata PUERTO LUZ (Amarakaeri) (Matsigenka, Huachipaeri) AMARAKAERI COMMUNAL RESERVE Salvación Queros (Huachipaeri) Santa Rosa de Huacaria BARRANCO CHICO KOTSIMBA Pillcopata (Matsigenka; Huachipaeri) Cosñipata Mining Protected areas Queros (Huachipaeri) Mazuko MADRE DE DIOS PUNO Manto Under exploration Planned or potential Indigenous territory Manú National Park buffer zone Manú Biosphere Reserve boundary KOTSIMBA 12,631 ft 3,850 m Cosñipata Mazuko MADRE DE DIOS PUNO Manto Deforestation 2000-2013 Gas block under exploration Urubamba Paucartambo Active deforestation Quince Mil Settlements (indigenous group name) Gas block under exploration Natural gas Urubamba Paucartambo Indigenous community Indigenous community in initial contact Isolated group in area In production Under exploration Pipeline Gas-drilling platform Exploratory well Cusco Source of the Madre de Dios Cusco Road Proposed road Matthew W. Chwastyk, NGM STAFF; VIRGINIA W. MASON SOURCES: INSTITUTO DEL BIEN COMÚN, PERU; Instituto Nacional de recursos naturales, Peru; AMAZONIAN NETWORK OF GEOREFERENCED SOCIO-ENVIRONMENTAL INFORMATION (RAISG); MATT FINER, MONITORING OF THE ANDEAN AMAZON PROJECT; perúpetro s.a.; GLENN SHEPARD

Park guards in Manú, though spread thin, are a deterrent to small-scale loggers, miners, and hunters, but most observers agree that Manú’s sheer remoteness has been its best defense. “It is protected by its inaccessibility,” says Ron Swaisgood, scientific director at Cocha Cashu. But “gold mining and oil exploration are starting to eat away at the buffer areas. Some of these degradations can leak into the park.”

A road would speed that leakage considerably, and the governor of the Madre de Dios region, Luis Otsuka, is promoting one that would extend farther along the Alto Madre de Dios to Boca Manú. No longer would tourists—or loggers, or miners—have to use expensive, gas-guzzling boats to get there. The village of Diamante lies along the proposed road. Its residents are eager for it, so eager that they’re working hard to get it built.

When we arrive in town on our way out of the park, it seems deserted. Brightly painted houses cluster along the river. Fleece blankets with pictures of tigers and peacocks dry in the sun. The silence is interrupted only by a few kids and some roving chickens and pigs.

We find one shop open and have a beer, our first cold drink in weeks. As the day lengthens, men start filtering back into the village, each holding a machete, his back wet with sweat. Among them is village president Edgar Morales. He says the men have been cutting a trail for government surveyors, so that they can collect the data needed to gain approval for the road.

View Images Loggers remove softwood timber just south of Manú Park. Valuable hardwoods such as mahogany have already been logged illegally along nearby roads and rivers. But the park itself has largely been protected by guards, and its inaccessibility.

People in Diamante, Morales explains, grow a lot of bananas and take them by boat to sell in nearby Boca Manú. But they know they could get a better price in Cusco, and in general they feel ripped off. “Our kids who go out and work lumber get nothing,” Morales says. “We have good flatlands here, with loamy, dark earth. We can grow plantains, papayas, pineapples, yucca to sell in Cusco. Soon people here will have their own cars. People have warned us that bad people will come in and take our land, but we have 800 people here. We can defend ourselves.”

Peru’s Environment Ministry, which runs the park, opposes the road, and so do most of the indigenous residents of the region, according to park director John Florez. “The people demanding it are the colonists,” he says. “Diamante is the only native community asking for it.”

Mauro Metaki, a genial, mission-educated schoolteacher in Tayakome, is opposed to the road and frustrated that a few people in his community are in favor of it. “The regional governor is lying,” he says. “They are fools to believe him. He’s making them all excited saying that the road will benefit them. It will benefit him and his white friends, who will come in and take the lumber, the animals, and the gold. There will be nothing left for the Matsigenka.”

Sitting on the open first floor of his house, looking out over wild palms and cultivated bananas, mangoes, and sugarcane, listening to the soulful hoots of howler monkeys from across the river, Metaki explains how he sees Manú. “There’s a park, but there are also people living here—right in the middle of it,” he says. “Sure, we hunt and fish, but we take just a little to feed our families. We know how to take care of the forest.”

View Images Elena Chogotaro Oyeyoyeyo (foreground, with her baby) is among the Matsigenka from isolated areas who come to the settled village of Yomibato to get goods and services. Silverio Mambiro Shinti (standing) came to fish and to get an ax. Then he stayed and built a house.

John Terborgh, the Duke ecologist, has for many years expressed the hope that the Matsigenka would leave the park—voluntarily, he emphasizes—for the wildlife’s sake and for their own economic opportunity. “Do I think there ought to be permanent settlements inside national parks?” he asks. “No. In this respect the U.S. model is a good one I am happy to endorse. Would you like to have farms and villages in Yellowstone or the Great Smoky Mountains?”

Some young Matsigenka are indeed beginning to leave, or at least to come and go; secondary schooling inside the park is limited. Samuel Shumarapague Mameria, a former president of Yomibato, says that young men who’ve left come back changed. “When they are here, they drip herbs in their eyes and they eat the piri-piri,” he says. “When they go downriver, they eat rice and onions and lose their hunting ability. Their heads are full of books and learning.” Similarly, he says, “when girls go downriver, when they come back, they are too lazy to spin cotton. Their souls only think about reading and writing. Their souls and bodies are full of paper.”

Some who go downriver don’t come back at all, taking jobs in logging and other professions. “You see young men leaving for work, abandoning a wife and kids, and starting new families outside,” says biologist Rob Williams. Most of the Matsigenka I talked to wish that there were adequate schools inside the park—and that their children would stay there.

The Matsigenka’s image of Manú, like their image of nature, includes them. Whereas Terborgh and other Western biologists come from a culture that separates humans from nature—both philosophically and as a conservation strategy—the Matsigenka see themselves as part of the natural order. They hunt monkeys, and so do jaguars. Key plants and animals have spirits and agency, just as people do, and there’s no hard boundary between them. In Yomibato I was told matter-of-factly about a nice old man who turned into a jaguar and started killing chickens and dogs. Finally the jaguar was shot through the heart with an arrow and burned so that his spirit wouldn’t come back again.

View Images Matsigenka schoolchildren on a field trip eat fish caught by a traditional method: Barbasco roots are pounded into a paste and swirled in the river. The roots release rotenone, a toxin that stuns fish but not the people who eat them.

The Matsigenka and other indigenous people in the park are not only hunters; they’re de facto armed guards. If all the people who live inside Manú were to leave in search of education and paid work, Shepard argues, other people would come in—and they’d probably be less willing to abide by the rules against guns and commercial extraction of resources. “There are no demographic voids in the Amazon,” he says.

Today the Matsigenka act as an advance warning system. With their homes strung along the park’s main rivers, they would notice if loggers or miners or coca farmers moved into its core, and with their deadly arrows, they—along with the Mashco-Piro—might be an immediate deterrent. In Brazil the Kayapo have been evicting illegal loggers and miners.

And as long as the Matsigenka don’t use guns, Shepard says, their hunting isn’t doing much harm. He and his colleagues asked dozens of hunters to record their hunting: the animals they killed, the ones that got away, and how long they traveled to find them. They found that the Matsigenka hunt five species enough to reduce their populations—spider and woolly monkeys, white-lipped peccaries, and two birds, the razor-billed curassow and Spix’s guan.

But they also found that even if the Matsigenka population were to grow rapidly over the next 50 years, no more than 10 percent of the park would be depleted of spider monkeys—unless the hunters acquired shotguns. With guns they could quickly empty the forest of monkeys within a day or two’s walk of their villages. If the Matsigenka have so far abided by the park’s firearms ban, it may be because they understand that guns might be at best a short-term boon.

View Images For the Matsigenka who live in the village of Yomibato, the river of the same name is a vital source of food and transportation. It’s also where students from the village school have their daily swimming lessons and frolic during recess.

Five hours into our hunt Elias and his family are still scanning the treetops, looking for monkeys. Traveling along a ridge, we come across a mysterious, foul object—a wad of green leaves drenched in a dark liquid and covered with flies. Martin, Elias’s son-in-law, explains that jaguars eat leaves and vomit them up, purging “just as we do, to be better hunters.” Nearby Elias points out a wet stain of jaguar urine. “That piss is from now,” he says.

Suddenly the jungle explodes with deep, urgent cries. An unseen troop of woolly monkeys, only a few yards down the ridge, is sounding a jaguar alarm. The cat is close. I freeze and feel a wash of adrenaline. Elias calmly sits down on a log and reaches into his net bag. He pulls out some roots of piri-piri and chews them.

Properly medicated, he plunges into the thick vegetation. He plans to take a woolly monkey and a jaguar too, if he can. Jaguars don’t just compete with the Matsigenka for monkeys; they also kill children.

The rest of us wait, then creep down the trail. A moment later the rain begins. It shoots from the sky with the ferocity of a pressure washer. The noise of our movements now completely drowned out by the cacophony of a million glossy leaves being battered by raindrops, we sprint off the exposed ridge and take shelter under the trees. In a few minutes Elias appears, smiling, empty-handed, skunked by the storm.

Back at home he has no monkey meat to give his wife. But a baby spider monkey is warming itself by the fire. The Matsigenka love to tame forest animals as pets. When they do manage to kill a spider monkey, it often turns out to be a female slowed down by young offspring, and they bring the orphans home. Once the monkeys grow up, they’re released back into the forest. This baby monkey is drenched to the skin, like the rest of us. We join it by the fire. The smoke rises above the papayas and floats across the Yomibato, out over the forest.

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