VIRUNGA NATIONAL PARK, Democratic Republic of Congo - Not far from a hillside where several mountain gorillas shot dead last summer lie buried, park ranger Innocent Mburanumwe peered across a primordial canopy of treetops into what may be the most dangerous game reserve on earth.
The lush sanctuary - home to some of the world's last mountain gorillas - was thrust onto the front lines of Congo's latest war in September. Since then, the fragile habitat in the Central African highlands has been overrun by rebels and soldiers, transformed into an off-limits war zone.
In the world of wildlife conservation, the biggest worry most rangers face is the extinction of endangered animals. But in Virunga National Park, where more than 120 rangers have been killed over the last decade, they also worry about their own survival.
In recent months, some have dodged bullets while driving in their cars. Some have spent nights hiding under beds with their families. All were forced to flee the park's so-called gorilla sector when rebels swept in, some taking shelter in tents on the sanctuary's edge.
"There are undoubtedly risks associated with this job," said Mburanumwe, 35, whose brother - also a ranger - was killed in the line of duty a decade ago. "But our concern is for the gorillas. That's the reason we're here."
The gorillas have the potential to draw tourist revenue to a desperately poor region and bring in vital funding through conservation groups. Over the last 12 months, though, rangers have watched helplessly as the gorillas have been massacred.
Last year was the bloodiest year on record for the apes since American researcher Dian Fossey first began working in Congo in the mid-1960s to save them. The toll: 10 shot and killed, two others missing. The rangers don't know for sure who killed the gorillas, but they believe illegal charcoal traders are trying to sabotage the park for easier access to its trees.
Now armed groups have seized the habitat. With park staff unable to set foot inside the reserve for the last four months, the gorillas' fate is unknown.
"Nobody knows what's happening to them, nobody can track them anymore," Mburanumwe said, eyes fixed on the verdant slopes of dormant Mikeno volcano, where about 190 of the world's remaining 700 mountain gorillas live.
"It's a catastrophe," he said, turning away from the mountain, its mighty peak rising through the mist. "For them and for us."
When Mburanumwe was a boy, he watched his father put on a uniform and boots every morning. His father was a ranger. He became one, too.
Rangers in eastern Congo take great risks to save animals in a part of the world heavy with human suffering. The job doesn't come with a steady paycheck, but it offers the security that comes with cradling a weapon in a region where the most powerful people - soldiers and militiamen - are usually the best armed.
Another ranger, 46-year-old Diddy Mwanaki, joined the park service in 1991 after a friend tipped him off to a vacancy. It's the only job he's ever had.
After weeks of training, Mwanaki was given a camouflage uniform and a rifle and taught how to fire it. Soon he was deployed with a radio-equipped team of trackers, observing the massive, jet-black gorillas that he and other villagers back then thought of as "monsters."
"I was surprised to find they were just like man, except that they cannot speak - at least not like we do," Mwanaki says. "It's true they can be aggressive - but only when they are aggressed. This is not always true of man."
In the past decade, about 120 of the 660 rangers have been killed on the Congo side of the border alone, a tenth of them in the gorilla sector.
Meanwhile, the gorilla population in Central Africa's Virunga Conservation Area has risen by roughly 10 percent over the same period to about 380 today.