Conservation International

“It was the custom. We didn’t know any better,” he adds. “But now that we have learned what a unique animal it is, and how it can even bring tourists here, we want it protected.”

The M23 rebellion has forced the park authorities to shut down what was a fast-growing tourism trade. In 2009 the park received 550 visitors; last year 3,000 tourists came to Virunga and that figure was projected to rise to 6,000 in 2012.

To De Merode's relief, the rebels and government forces this week agreed to allow a team of 45 rangers to search for and monitor the mountain gorillas. The Virunga park authorities said some of these gorillas have not been seen for over 10 weeks. There was further heavy fighting in the area this week, heightening fears for the gorillas' safety.

"There are around 210 mountain gorillas in the park, which is roughly a quarter of the world's population," he says.

“Frosts are (now) more frequent and last longer. The sun burns harder,” says Arapa. “Before (washed) clothes took two days to dry, now just one day.”

Eddy Wilber Ramos, an agronomist and Gomel Apaza’s assistant, says tougher times mean “there are dozens of families who are migrating from these areas because they are no longer able to tolerate the climate conditions in which they must work.”

Some farmers also argue that the Green Revolution brought with it a competitive, individualist model for farming which weakened cooperation among farmers.