This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
The endangered eastern chimpanzees (Pan troglodytes schweinfurthii) in Rwanda's Gishwati Forest could be doomed unless they increase their gene pool, an unlikely event if humans don't get out of the way first, the Global Post reports.
After decades of habitat loss, just 20 chimpanzees—up from 13 in 2008— live in the remaining 8.8 square kilometers of Gishwati. That makes it what many believe to be the world's densest population of chimpanzees.
Of course, Rwanda also has the highest human population density in all of Africa, with more than 10 million people crowded into a land that has already lost much of its natural resources.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
But because most of the area around Gishwati has long since been converted to farmland (some of that illegally), there aren't actually a huge number of people nearby. The main human settlement near the forest is the tiny village of Kinihira, which saw a number of its residents die from floods and landslides caused by unsustainable farming practices. Now the Gishwati Area Conservation Program (GACP) is proposing moving some of the remaining citizens out of the area so a 64-kilometer forest corridor can be planted, linking the 20 chimpanzees in Gishwati to 400 of the primates living in Nyungwe National Park.
The two forests were connected years ago, before agriculture separated them.
Also known as the "Gishwati LifeBridge" (pdf), the corridor would include some 4,000 hectares of new plantings and would stretch from Rwanda's southern border almost all the way to its northern border.
The GACP has already been successful in improving conditions in the forest. Since 2007, the program has increased the protected area of Gishwati by 67 percent—from about 885 to 1,485 hectares—by annexing land that had been occupied by farmers and cattle ranchers illegally. That has helped the chimpanzees, giving them breathing room to breed and grow their population. But they still need more space and more genes to thrive.
Benjamin Beck, director of conservation for the Great Ape Trust, which directs and supports the GACP, said the project will help create ecotourism jobs as it moves the local economy away from unsustainable agricultural practices. According to the Trust's Web site, the corridor would also "provide water catchment and purification, prevent soil erosion, [and] replenish soil fertility." The GACP has helped to improve the local economy by hiring people to protect the forests and supporting sustainable business activities.
It's uncertain exactly how many people would need to be moved, because the exact coordinates of the corridor have not yet been set in stone. According to the Great Ape Trust, "The exact route will be determined by the realities of current human land use. We want to find a route that avoids houses, schools, farms, roads and power lines—not an easy challenge in today's densely populated Rwanda."
Critics of the plan say it is not worth uprooting any people solely for the benefit of 20 chimpanzees.
The GACP proposal—part of Rwanda's land-use master plan—is currently under review by the country's parliament.
The eastern chimpanzee can also be found in the Central African Republic, the Democratic Republic of the Congo, Uganda, Burundi and Tanzania. Some scientists argue that the subspecies does not actually exist and the animals should be counted with another subspecies, the central chimpanzee (P. t. troglodytes), which are found in some of the same countries.
Photo: Eastern chimpanzee and child, via Wikipedia under Creative Commons license
