In the Kingdom of Gorillas, page 11
At our base camp, a surprisingly large and active hyena population chortled and hunted around us through the night. This fantastic auditory experience was totally unexpected at high altitude in a rain forest. Less positive was a tale we had recently been told of a tourist in Kenya who slept in an open tent wearing his boots. A hyena, attracted to the scent of leather, pulled him out by one boot at night and mangled his foot before it was driven off. Even if Bill didn’t sleep with his boots on, it was not a reassuring thought. Added to our concerns about military movements, we slept little and were happy to move on in the morning.
Our last camp was in the Gahinga–Muhavura saddle. There, a contingent of Rwandan soldiers stood guard inside a small tin hut. They were nervous, though it wasn’t clear whether this reflected the military situation across the border with Uganda, two hundred yards away, or their fear of wildlife in the park. They were not an impressive group, and several seemed happy to have company.
We were now in an area of the park that had never supported many gorillas, even in Schaller’s day. Yet we still needed to cover a large amount of terrain. Fortunately, Gahinga had very few ravines of any significance and its tall stands of bamboo formed cathedral-like arches that were much easier to walk through than the bamboo thickets to the west. At lower elevation on Gahinga, though, we did encounter strange Mimulopsis trees, whose raised stilt roots were adept at tripping tired legs. We found some old gorilla nests at several sites, but no sign of passage within the past six months. Our own presence, however, triggered volleys of sharp Piao! alarm cries from resident troops of golden monkeys (Cercopithecus mitis kandti), a medium-sized monkey endemic to the region whose vivid golden mantle is as striking as its cry.
Muhavura would be our last challenge. Its 13,540-foot cone made it an almost perfect bookend to Karisimbi in the west. Fortunately, most of the Ugandan sector was covered with a recent lava flow that could not support gorillas, so we did not have to risk an encounter of the military kind. During our brief forays into the Ugandan sector we saw no sign of wildlife, though we did hear hunters using dogs with bells. Twice gunshots echoed from below. Hiking on Muhavura was not too difficult: its slopes were steep, but without any significant physical or vegetative barriers. Much of the mountain’s mass was above the treeline, where an open steppelike environment predominated. Northern double-collared sunbirds flashed their metallic green and purple plumage while brilliant red and green long-tailed malachite sunbirds darted manically about this alpine moorland, their long, thin beaks adapted like those of hummingbirds to drinking nectar. Bushbuck browsed here, too, but quickly barked and bolted on sight.
Finding no gorillas one day, we decided to explore the summit. Near the top we were forced to crawl through a dense thicket of gnarled, moss-covered alpine Senecio, a woody plant that grows over several centuries to a height of ten to twelve feet. This entangling complex extended for hundreds of yards in what seemed like the world’s largest natural jungle gym. Our reward for passage was a perfectly round crater lake perched on Muhavura’s summit. The lake was no more than twenty yards across, its surface reaching to within eighteen inches of the rim. Bill wondered if it ever overflowed, then giggled as he knelt to drink from the cold dark source at the top of the world. Clouds came and went in seconds. During clear moments, we could see lakes far to the north in Uganda and the crowded fields of Rwanda to the south. With the return of clouds, a chill crept under our skins. We reluctantly left our watering hole with a view as the day drew to a close.
Our sole gorilla contact on Muhavura was also the last of the census. Late one afternoon we encountered fresh gorilla sign. We backtracked to make two nest counts, then returned to contact the group and complete our count the next morning. We confirmed the presence of seven individuals: one silverback, two adult females, another unsexed adult, and three young gorillas. Leading downslope, the fresh trail of compacted herbs wound past the yellowed skeleton of a jackal, its foreleg still held in the death grip of a poacher’s wire trap. Nearby, we could hear the gorillas. Bill moved closer until he saw a hand reach into a bush barely twenty feet away. He then climbed a tree, revealing the face of an older female, sitting in a day nest eating Galium.
With a severe stare and a reddish brow … she stares back for nearly a minute, moving her head back and forth, giving time for a noseprint. She then flees silently with others moving ahead of her. … By 13:10, fear dung is prevalent.
Silent flight and diarrhea were common reactions of wild gorillas when confronted by humans. They were also signals for us to leave them alone and complete our final nest counts.
For four more days we moved methodically counterclockwise around Muhavura, until we reached the open lava field near the Rwanda–Uganda border along its eastern slope. We crossed and explored sixteen ravines in that time, several of which contained prime gorilla habitat. Yet we never saw another gorilla, nor any sign of other animals besides birds. We had seen the same sort of unoccupied habitat at the extreme western end of the park on Mt. Karisimbi. This meant that there was still room for the gorilla population to expand. But it also meant that these sectors far from the central park headquarters were killing fields where poachers ruled and where gorillas had been exterminated.
On our last afternoon we walked out of the park and down to an old colonial estate at Gasiza, near the base of Mt. Muhavura. The house needed paint and the foundation was cracked, but its size, stone arches, and panoramic views testified to a more glorious past. Now it was the home of Drs. Alain and Nicole Monfort. Alain and Nicole were Belgian ecologists with a deep love for the Akagera National Park in eastern Rwanda: a savanna-wetland complex with a warm, dry climate. Alain disliked the rude Virunga environment, but had worked to improve park management and security during his brief tenure in the north. As hosts, Alain and Nicole received the first unofficial census results and other news from the forest. But mostly we enjoyed good food, good wine, and good company. After weeks of functional Swahili, Bill was happy to use his much richer French vocabulary.
SOLVING CONSERVATION PROBLEMS is like putting together a jigsaw puzzle for which there is no picture on the box, many parts are missing, and there is too little time to examine all the remaining pieces. Our challenge was to fill in the most complete picture possible through a combination of biological and socioeconomic research. The census provided the first pieces to the very complex puzzle of how to better understand and protect the mountain gorillas.
The hike home from Gasiza to Karisoke covered about twenty-five miles and took just over eight hours. It was ample time for Bill to reflect on what he had learned and what it might mean for the gorillas. George Schaller had carried out the first Virunga census in 1959–60. A simmering civil war in Rwanda prevented him from surveying certain areas, but his combination of direct counts and estimates based on habitat characteristics* produced a baseline total of four hundred to five hundred individuals. The next census was conducted by a team of Karisoke researchers over a three-year period between 1971 and 1973. Their findings showed a dramatic decline to 250 to 275 gorillas, with a parallel decrease in average group size and percentage of young. As he walked through farm fields along the park edge, comparisons with the current numbers churned in Bill’s head.
The good news was that the population appeared to be stabilizing after its free fall in the 1960s. Our minimum count was 252 individuals, which would later be extrapolated to an estimated population of 260. Better yet, we had found forty-two infants under three years old, versus only thirty-three in the same age class only five years earlier. Average group size had also increased, but only because the number of groups had declined from thirty-one to twenty-eight. The bad news was that gorillas were avoiding the eastern and western extremes of the park and concentrating in the center, especially around Mt. Visoke. On Mt. Mikeno, where Schaller had counted more than two hundred gorillas, there were only eighty-one. Mts. Sabyinyo, Gahinga, and Muhavura supported only thirty-four gorillas in five groups. Objectively, it was a mixed message at best. Emotionally, it was a great relief not to find further losses, especially after the bloody events of the past year.
The bright red and yellow flower displayed on the outer fence of a household compound, or rugo, signaled that fresh sorghum beer had been brewed inside. Big Nemeye, coming off an involuntary stint of sobriety for the census, homed in on the signal like a bee foraging for nectar. Soon he had negotiated several large bowls of umusururu for himself and each of the porters. The light brown liquid flowed down their throats as easily as the beer’s Kinyarwanda name flowed from their lips. Bill declined a proffered bowl because of his distaste for the sorghum chaff that came with the beer. With team spirits higher we continued west toward Karisoke.
Near the base of Sabyinyo, the typically rich soils of the Virunga piedmont gave way to a hard lava pan. Hollow thumping sounds revealed the presence of extensive natural tunnels below our boots. Nemeye commented without elaboration that many local people hid, and sometimes died, in these caves during past times of troubles. Aboveground, the shallow soils supported patches of grass between rocky outcroppings, providing a rare opportunity for herdboys in this region to graze their cattle. Bill assumed the same cattle would move illegally into the park once we had passed.
Beyond Sabyinyo the soils deepened and the land returned to its natural richness. Lush rows of potatoes and beans extended to the horizon, juxtaposed with large square patches of white pyrethrum flowers. It was an attractive landscape, set against the backdrop of towering volcanoes. Only the occasional Markhamia or Hagenia tree stood in mute testimony to the fact that all of this land had been torn and cleared from the park just ten years earlier.
WHEN RACHEL CARSON published Silent Spring in 1962, the Western world was forced to confront the devastating effects of DDT on wildlife and human health. DDT emerged as a potent insecticide during the post–World War II chemical revolution. It allowed American and European farmers to greatly expand their control over damaging insects and increase their yields of fruits and vegetables. But it also killed pollinators and other beneficial insects. It moved insidiously up the food chain to poison frogs, fish, birds, and people. When politicians finally listened to the scientific evidence, DDT was banned and the race was on to find less toxic alternatives. Kenya was already growing pyrethrum, a daisylike flower that produced a natural insecticide called pyrethrin. With a new world market to satisfy, exports of pyrethrin skyrocketed. Kenya’s efforts to expand production, however, ran up against its limited amount of high-elevation land required to grow pyrethrum. Rwanda already grew some pyrethrum in the Ruhengeri region and there was more highland habitat in the park.
With money from the European Development Fund—and no environmental impact assessment—the Rwandan government rushed forward with a program to spur pyrethrum production. Twenty-five thousand acres of lower elevation forest habitat were cleared from the Parc des Volcans in 1968 and 1969. Five thousand families were awarded five-acre plots, called paysannats on which they were supposed to maintain 40 percent of their land in pyrethrum. In a country beset by chronic land shortages, it was a popular program among northern Rwandans—even if large blocks of the cleared land were illegally claimed by senior political figures from the region.
By the late 1970s worldwide demand for pyrethrin was already in decline. Western laboratories had succeeded in synthesizing several less toxic alternatives to DDT, with shorter and less problematic supply lines than those stretching all the way to landlocked Rwanda. Local farmers adapted by ignoring pyrethrum production quotas and growing more marketable—and edible—white potatoes. Gorillas, too, adapted to the loss of habitat by moving higher on the mountain. But with the lower park limit now at almost nine thousand feet, the gorillas were exposed to near freezing temperatures every night. Pneumonia, already their number one cause of mortality, would kill even more of the very young, old, and sick. Though no one ever recorded how the gorillas had formerly used the area cleared for paysannats, it was certain that they had lost a part of the forest rich in many of their preferred foods, including large areas of bamboo.
It was impossible to stand at the foot of Visoke at the end of that day and feel optimistic, despite the positive census findings. The surrounding landscape looked as if people had been living there for centuries. Yet 40 percent of the Parc des Volcans—22 percent of the entire Virunga forest—had been cleared in the past ten years. Habitat that had supported mountain gorillas for millennia had disappeared in a relative instant. Whatever the census numbers said, it seemed unlikely that there was enough habitat left for them to survive within the retreating park boundaries.
Chapter Nine
Life in a Salad Bowl
PUCK AND TUCK sat shoulder to shoulder, looking out over the fields and thatched rugos that stretched to the south as far as the eye could see. When Amy found a better vantage point, she could see that they were also eating thistle. But why had they walked out of the park and ventured almost thirty yards across open farmland to clamber up on that rocky knoll? Did they know that gorilla food was hidden in the midst of the unappealing potatoes and pyrethrum? Puck was barely nine, four years older than his brother Tuck. Both were too young to remember the area before it was cleared from the park; but both were still young enough to let curiosity lead them on a reconnaissance run into new territory.
Amy had never seen any gorillas beyond the park boundary before. Now all she could do was imagine their motives—perhaps the view on a rare clear day?—and wait with some concern for them to rejoin the group. Within ten minutes, Puck and Tuck had finished their snack, ambled up the gully between two rows of potatoes, and slipped back into the forest. They would not visit the fields again while we were there.
APPLIED CONSERVATION RESEARCH was extremely rare in the 1970s. The few people committed to long-term fieldwork in African rain forest environments were almost all behavioral scientists. Jane Goodall and Dian Fossey were leaders in this field and their work fed an insatiable global appetite for information about the lives of chimpanzees and gorillas. As the plight of these species became increasingly clear, however, so did the need for sound information about how to save them. Amy’s study of mountain gorilla feeding ecology was designed to inform those responsible for gorilla conservation about these endangered creatures’ most essential requirements for survival.
Every species has basic needs: food, water, security, social support, opportunities for reproduction. Food and water come first—and mountain gorillas derive both from the rich plant life of the Virungas. The recent loss of 40 percent of the forest habitat of the Parc des Volcans raised deadly serious questions about the long-term viability of the remaining 260 Virunga gorillas. Recovery to the population levels of four hundred to five hundred gorillas recorded by George Schaller seemed out of the question.
Almost twenty years later, Schaller’s 1960 study of the mountain gorilla remained the only significant source of information on gorilla feeding ecology. In addition to his comprehensive analysis of their behavior and social organization, Schaller documented the gorillas’ use of diverse habitats on Mt. Mikeno in the Congolese sector of the Virungas. He also introduced the use of direct observation to record the foods consumed by gorillas. This was a great improvement on the indirect methods of dung and stomach content analysis that were considered the only feasible way to obtain information about wild animal diets at that time. Yet despite Schaller’s Promethean efforts, there was much more that we needed to know about the gorillas’ food and habitat requirements. Was Mikeno representative of the rest of the park? How much did the gorillas actually consume of the different foods available to them? Did they have preferences? If so, were choices based on quality or availability? Ultimately, could the now diminished forest meet their long-term needs?
ONE DAY IN JUNE, as our first long rainy season approached its end, Amy was watching Beethoven feeding about ten feet in front of her. Hearing a noise, she looked away to see who was moving through the thick undergrowth nearby. She had not yet seen all members of Group 5 and wanted to complete her daily count. Reassured that Pantsy and Muraha were accounted for, she turned to find that Beethoven had moved silently behind her, where he was reaching for a plastic bag she had stuffed with Galium. Amy reached as well, but lost the race. Beethoven grabbed the bag, strutted a few feet away, and sat down with a confident look. As Amy watched in bemused shock, he reached into the bag and began to cram folded “wadges” of Galium into his maw, chewing steadily until he finished his meal. Dropping the bag by his side, he then nimbly removed a few strands of the clinging vine from his hairy forearm and ambled off to nap.
For Beethoven, this was a déjà dinner. For Amy it was lost data. As part of her research, she would monitor one group member for five hours almost every day. During that time she recorded everything the individual ate, what was within reach but wasn’t eaten, and what other gorillas within view were eating. She had devised a simple method to determine quantities of food consumed: replicating each individual’s feeding by sitting nearby and gathering equal quantities of whatever was being consumed. When the feeding was over, Amy’s duplicate meal was bagged, brought back to our cabin to be weighed, then dried for later nutritional analysis. If she had any qualms about choosing foods of similar quality to those eaten by the gorillas, Beethoven certainly dispelled them on the day of the great Galium heist.
Within a few months, the gorillas of Group 5 completely tolerated Amy’s almost constant presence. Every other day, she would leave the cabin at the break of dawn and hurry off alone to catch the group before it began feeding. On rainy days, she would often find the entire group still in bed. Most other mornings she might find several adults still lounging sleepy-eyed in their night nests, provoking nothing more than a few belch vocalizations. Amy returned the two-tone sound, like a deep clearing of the throat, to acknowledge her presence. The younger gorillas were usually already up and active, waiting for their parents like eager children on Christmas morning. After the last adult rolled out of bed, a decision would be made in silence and the group would move off behind either Beethoven or an older female like Effie. At this point, Amy would move close to her focal animal and stay near that individual throughout the morning. On alternate days, when she did five-hour afternoon focals, as these intensive observation periods were called, she would catch up with the group in late morning and then stay until their last feeding session ended and they began to make their night nests.
