Wildlife poachers and the African continent's seemingly perpetual civil wars were long thought to be the greatest threats facing the last remaining population of mountain gorillas in the world. Now, say conservationists, disease transmission from humans to primates might pose an even greater danger to their existence.
"Gorillas are not immunized against a lot of the viruses we get as humans," explains Eddy Kambale, a veterinarian with Gorilla Doctors, a group founded in 1986 and dedicated to treating sick or injured gorillas in the wild. "One virus can kill an entire population."
Mountain gorillas are critically endangered, according to the International Union for Conservation of Nature. Fewer than 900 of them remain in the lush forests that straddle the borders between the Democratic Republic of Congo (DRC), Rwanda, and Uganda. Kambale and the Gorilla Doctors aim to ensure that the population remains healthy and stable.
VICE News caught up with Kambale in the Virunga National Park in the DRC. He was checking up on a family of gorillas, but was particularly anxious to locate an injured adult male named Mawazo, who he treated two weeks previously.
Gorillas share about 95 percent of their genetic make up with humans. This makes disease transmission between the two species particularly easy. The recent outbreak of Ebola in West Africa, which may have originated from infected bushmeat, is just the latest instance of how the health of humans and wildlife are sometimes intimately connected.
But the problem cuts both ways.
"The most common illness we see in gorillas is respiratory disease, like influenza," Kambale told VICE News. Gorillas, he adds, are most likely to pick up the virus from visiting tourists. Because of this, wildlife enthusiasts, who want to catch a rare glimpse of a gorilla in its natural habitat, must wear a face-mask covering the mouth and nose. The stakes are high — infectious disease accounts for about 20 percent of gorilla deaths in the wild.
Kambale has worked with gorillas since 2004 and is accustomed all sorts of setbacks. He's been charged by angry primates and detained by rebel armies that patrol the contested eastern region of the DRC. But, standing in the lush Virunga National Park, a different sort of problem has frustrated his search for the injured gorilla — bush elephants, which cut a huge path through the jungle, obscuring the mountain gorillas' tracks.
"It's difficult to find the real trail, the one that belongs to the gorilla," he told VICE News, as the roar of several elephants echoed through the trees. "Not to mention, elephants are very aggressive. They can kill you."
Park rangers tasked with tracking the gorillas join Kambale on each of his expeditions, providing assistance and security. They're armed in case of stumbling upon angry elephants, or worse, a poacher.
Kambale says that with so few gorillas remaining in the wild, national park officials check up on the animals every day. But the daily interaction between trackers and primates, like the presence of tourists, comes with the risk that the trackers might infect gorillas with some sort of sickness.
After hours of trekking through towering groves of bamboo and avoiding vicious army ants and thorny bramble, Kambale and his team locate Mawazo and the family over which he presides. The group has eight gorillas, most of which are males. Mawazo and another silverback named Kidogo, says Kambale, are at war over the few females in the group. While Mawazo had consistently emerged the winner, the fights are taking a toll. On Kambale's last visit, a chunk of skin hung from above Mawazo's left eye, making him more susceptible to infection.
When an gorilla gets sick, Kambale and his team might administer an injection of antibiotics using a dart gun. In critical cases, the team sometimes separates an injured gorilla from the rest of the group in order to suture wounds. It's risky work — family members often become enraged when one of their kin is isolated, sometimes becoming aggressive and charging at the veterinarians.
"It's hard to make the decision to intervene," Kambale told VICE News. "In life, there is never zero risk, anywhere."
Kambale takes notes on the health of each individual. He monitors the pace of their breaths and scans their eyes and nose for any liquids that might indicate the onset of illness. Everyone seems healthy, says Kambale, snapping a few photos of the group, particularly Mawazo, whose wound seems to be healing well.
An hour has passed since finding Mawazo and his group and the sun is beginning to slip behind the mountain. It's time for Kambale and his team to make the trek back home. The gorillas too must start to build their nests where they will sleep for the evening.
Kambale will return in a couple weeks to check upn on Mwazao. By then, he may have lost his fight to Kidogo. Either way, Kambale says he will be there to help keep the family healthy.
In the last 25 years, Gorilla Doctors has performed over 400 medical interventions. This year alone they have treated two outbreaks for respiratory disease among mountain gorillas. Neither resulted in casualties. With the right approach to veterinary care and a well-managed tourism program, Kimbale remains hopeful that these animals will continue to inhabit Virunga National Park for generations to come.
"Our job is to save the gorillas, one at a time," he said.
Elaisha Stokes is a 2014 International Women's Media Foundation reporting fellow in the Democratic Republic of Congo.