The doctors’ scrubs are khakis and T-shirts, with surgical masks slung below their chins. Their ambulance is a four-wheel drive, light tan with a stern-looking gorilla emblazoned on the side. Their surgical instruments are a camera, GPS, and medical chart. Guiding this medical mission are their nurses: a group of steel-witted trackers armed with machetes.

Separating the doctors from their patients is the dense foliage and rebel-filled jungles of the Democratic Republic of Congo, home to a quarter of the world’s last 880 mountain gorillas.

On a hazy morning, Martin Kabuyaya and Eddy Kambale embark on a check-up of a family of endangered gorillas living deep in Virunga National Park in eastern Congo. The men with the machetes walk ahead, hacking through the vines. The doctors take the strenuous uphill climb with long, leisurely strides.

Kabuyaya and Kambale are the only two veterinarians tasked with caring for the estimated 200 gorillas who make their home in Virunga, Africa’s oldest and most biodiverse national park. They’re employed by an organization called Gorilla Doctors in one of the world’s most dangerous regions, a place that is perilous both for the animals and for their caretakers.

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Their job is not only medical—it’s diplomatic. Eastern Congo has suffered 20 years of violence and lawlessness from a long-simmering war that has left 5 million people dead. Along with gorillas, the 2 million-acre park is home to at least a dozen rebel groups, including the last vestiges of the perpetrators of the Rwandan genocide. To reach their patients, the doctors must frequently negotiate with various heavily-armed rebels for access to the gorillas. They’re not always successful.

Hacking through the thick brush, Kabuyaya and Kambale and their team have hiked back to the last known GPS location of the ape family. From that point on, the tracking is done by sight: with eyes trained to the ground, they follow crushed leaves and droppings. They’ve already traveled deep into the jungle when they realize that the trail is no longer gorilla-made—it’s the path of a herd of unpredictable and deadly forest elephants. They quickly backtrack. Discarded bamboo sticks are spotted and feces are examined. A gorilla passed here three minutes ago, the trackers say.

“Now you see,” Kambale says in the confusion. “If one rebel group comes in this jungle how can you find them?”

Kambale, a 42-year-old father of three, is the head field veterinarian. He has spent more than a decade treating mountain gorillas in the Democratic Republic of Congo, which means he’s navigated more than his share of wars and rebellions.

Within Virunga National Park, a battle rages over land rights, poaching, deforestation, and, most recently, oil. Decades of fighting have left gorillas—and their conservators—in the crossfire. More than 140 park rangers have been murdered in the park since the outbreak of Congo’s first war in 1996.

Gorilla Doctors was created around that the same time, in accordance with an idea that gorilla researcher Dian Fossey had been working on when she was killed in Rwanda a decade earlier. Today, Gorilla Doctors has veterinary teams working in the forested triangle of Rwanda, Uganda, and the Congo, home to the world’s last mountain gorillas.

In the first year of work for both Kabuyaya and Kambale, Virunga National Park was embattled by insurgencies. Kambale started in 2004, the same year a rebel group called the National Congress for the Defense of the People (CNDP) invaded the park.

Three years later, they seized area where the gorillas live and occupied it during a vicious two-year battle with the Congolese government. Even deep in the jungle, there was no escaping the conflict. “We can’t go far from politics,” says Kambale.

With permission from the rebels, the doctors continued operating in the park. “They can kill you,” Kambale says. “When we’d come into the forest they were checking our bags. It was stressful. You can lose your life, they can take you out in the forest and you disappear. Nobody would wish to work under those conditions.”

Sometimes, when the road from his home in the nearby city of Goma was too perilous, Kambale traveled a circuitous route into the jungle through the forests of neighboring Rwanda or Uganda. In 2006, he was captured after accidentally stumbling into a rebel’s camping site. They took him and his group into an old building and kept them for the night. He was released after he promised not to come again, but his colleague’s clothes, camera, and car battery were taken.

Yet Kambale shrugs off the work’s dangers, noting that no job in eastern Congo carries a guarantee of zero risk.

After three hours of hiking, a machete swing through the brush reveals a clearing filled with the hulking shapes of a gorilla family. The doctors approach with guttural grunts that signify their good intentions, but the creatures are occupied by a leisurely afternoon snack and barely notice. The doctors strap on their face masks and evaluate their patients.

The enormous, silver-toned patriarch, Mawazo, is lounging on his back, a bamboo stalk in his mouth and a female at his side. His group of eight has sprawled out over a heavily curtained area. There’s a gaping wound on his brow, which is what brought the doctors to him, but they observe it’s healing nicely. “He’s quite strong,” Kambale notes, camera at his eye and notepad in his hand.

Their approach is hands-off. Kambale zooms in with his camera lens as a female yawns, to survey her teeth and tongue. Another gorilla sits down and Kambale counts her breaths to check for respiratory disease, an ailment with the potential to wipe out an entire clan of gorillas. “The animals don’t tell you ‘I have pain here, I’m sick,’” says Kabuyaya. So they must observe from a distance, watching for abnormal behavior.

For more serious medical treatments, a cross-border team of intervention and protection specialists is called in. They might need to dart an animal with sedatives from afar, particularly if it’s a large silverback or a baby protected by its mother, and then perform surgery or take a biopsy on the jungle floor.

This park administration, led by a workaholic Belgian prince, has poured resources into gorilla preservation, with the hopes it will attract the kind of million-dollar tourist industry that has blessed neighboring Rwanda and Uganda.

Before park warden Emmanuel de Merode took the reins, Virunga experienced what the staff now refers to simply as “the massacre.” Over the course of two months in 2007, seven gorillas were killed by poachers. Body parts were trafficked out of the park and babies were sold. Rangers found a gorilla head discarded in a toilet. Ultimately, the park director at the time was charged with orchestrating the killings—he apparently wanted the park cleared of gorillas so he could deforest for charcoal production without obstruction from conservationists.

“How can people kill these gorillas? They are like humans,” Kabuyaya says. “You realize they must be protected like humans.”

The 33-year-old Kabuyaya graduated from veterinary school in 2009 and joined Gorilla Doctors three years later. His timing was fortuitous—another militia group seized Virunga that same year. The M23 insurgency refused to let the park’s doctors and rangers in to check on the animals for six months. During that time, rebels filled their coffers by leading gorilla tours for unscrupulous tourists.

“It was not strange for me because in the DRC we are used to fighting,” Kabuyaya says of his job’s rough beginning. There were no widespread killings this time, but tragedy struck when a baby gorilla orphan fell ill with diarrhea at the park’s sanctuary, and the doctors were blocked from making the hour drive to deliver treatment from a nearby city. It died overnight.

After more than five hours of hiking, the gorilla doctors have finished their medical trek and are taking a short break in Virunga’s lodge, a gorgeous open porch that looks over miles of jungle. It’s just a short walk from the sanctuary that held the deceased gorilla baby, and now is home to four others. Kambale shakes his head at the memory. “It was sad, so sad. Shameful. Why couldn’t we save it?”

In the past three days the two doctors have already examined five different gorilla families, an impressive feat considering the distance traveled just this morning. They make the journey into Virunga each month and spend a week tracking, observing, and treating various families. The rest of their time is spent caring for lowland gorillas across the region.

This grueling schedule leaves them only a week per month to see their human families. “Sometimes they say, ‘It’s like you married a gorilla,’” laughs Kabuyaya.

But it’s not just a love of the intelligent apes that keeps the doctors going. It’s a deep patriotism and faith in the Congo’s recovery—a belief that a long-awaited calm will come with from conservation and its benefits.

“I tell people, ’You can’t separate human health and animal health,’” Kabuyaya says. “We’d like to be the first to show it’s important to take care of the animals because our life and health depends on [them].”

“Congolese are conserving for all the world,” he adds.

“Sustainability first,” says Kambale. “Then peace.”

The International Women’s Media Foundation supported Nina Strochlic’s reporting from the Democratic Republic of the Congo.