The wild gorilla of equatorial Africa is the largest of the four great apes; the mountain subspecies was discovered in 1847 but first scientifically described in 1902. Until recently, this primate was thought to be a brutish and ferocious animal of the jungle. However, field studies have revealed that this huge pongid is shy, gentle, and introverted but curious, intelligent, and powerful.
In prehistoric times, wild gorillas ranged freely throughout central Africa. Today, however, this great ape is represented by only three geographically isolated subspecies: the lowland or valley gorilla of central West Africa, Gorilla gorilla gorilla; the slightly smaller highland or mountain gorilla of central East Africa, Gorilla gorilla beringei; and the lowland gorilla of East Africa, Gorilla gorilla graueri. The minor differences between the two major subspecies are that the mountain gorilla has longer hair (an adaptive advantage) and has a longer palate than the lowland gorilla and does not share its forest with chimpanzees.
Now a critically endangered species, the wild gorilla needs to be understood and appreciated in order to ensure both its protection and survival in captivity, as well as in its natural environment. It is estimated that fewer than 1,000 mountain gorillas inhabit the lush forest areas of central East Africa. Their ecological niche is gravely threatened by hunters, farmers, and poachers—thus the desperate plight of this mountain ape.
George B. Schaller, a zoologist, was the first scientist to seriously study the wild mountain gorillas in their natural habitat. His pioneering 20-month research project (1959-1960) remains a classic contribution to primate ethology. He has presented his important findings in two books: The Mountain Gorilla (1963) and The Year of the Gorilla (1965).
Gorillas are primarily terrestrial, quadrupedal climbers and knuckle walkers, living in the humid rain forests of Africa. In his extensive study of the mountain subspecies, Schaller concentrated on the ecology and general behavior of this remarkable great ape. His 466 hours of direct observation were made from the safety and viewing advantage of trees. Schaller was able to watch free-living gorillas wander through the dense jungle, forage on succulent herbs and vines (they prefer young secondary forest growth), groom and play, and build nests in the trees or on the ground. The zoologist observed no tool use, no meat eating, and no drinking of water. Both vocalizations and sexual behavior were infrequent. Of particular interest, however, is the gorilla’s chest-slapping behavior— an elaborate sequence of nine distinct acts by a provoked gorilla in order to frighten away a threatening intruder, thereby preventing physical contact.
Despite his dedicated study of this wild ape for nearly 2 years, Schaller never made physical contact with these mountain gorillas. Yet this incredible feat was later accomplished by the remarkable primatologist Dian Fossey.
During 1967-1985, anthropologist Fossey lived among the wild highland gorillas of the Virunga Volcanoes in central East Africa. (The lowland or valley gorillas of central West Africa still await rigorous study.) Her research camp, Karisoke, was located in the ancient rain forest of Mt. Vasokie—a tropical world of jungle, fog, and mist in Rwanda near Zaire. Encouraged by anthropologist Louis S. B. Leakey, Fossey had followed gorilla groups on the ground in order to observe them at close range during their leisurely day-long search for food. Fossey was very successful in establishing a rapport with these great apes; she patiently learned to imitate their feeding methods, general sounds, and basic gestures. As a result of her relentless efforts, these curious and gentle giants of the primate world had slowly accepted the anthropologist’s presence. This acceptance allowed her to examine the uninhibited behavior of mountain gorillas under normal conditions in their natural range.
Fossey’s more extensive long-term, close-range, more intimate study of the mountain gorilla had been a rich and rewarding experience for her and science. Unlike Schaller, she had actually made physical contact with this great ape—the first time a scientist had touched this pongid in its own habitat.
In the glorious rain forests, this magnificent great ape is a peaceful vegetarian and primarily a ground dweller. A nervous gorilla will hoot, mouth a stick or leaf, thrash branches and vegetation about, slap its chest, run sideways, and finally thump the ground with its palms. It may even bluff a roaring “charge” as protective action, if necessary. The pongid’s alleged savagery toward humans is grossly exaggerated, for this fierce-looking and powerful ape will try to avoid physical contact with intruders. In short, unprovoked gorilla brutality is a myth.
Most gorillas live in small, stable, tight-knit, scattered groups that roam through the rain forests of central Africa and wander on the slopes of the Virunga Volcanoes. A social unit is dominated by the adult alpha silverback male. Other members include subordinate blackback males, adult females, juveniles, and infants. Protected by the dense jungle foliage and its huge size, an adult male mountain gorilla may live in an all-male small group or even as a loner. (Apparently the leopard, buffalo, and elephant are no threat to this great ape.) Each gorilla seems to possess a unique personality and a distinct voiceprint and noseprint. A gorilla’s staple diet is primarily folivorous; it consists of fruit, bark, thistles, nettles, celery, blackberry leaves, gallium vines, and other wild succulents. In its natural environment, the mountain gorilla has never been observed eating meat, insects, or birds’ eggs.
The gorilla is an intelligent animal, but in the rain and bamboo forests of mountainous central Africa, more fully developed mental capabilities and ingenuities probably would not have increased its fitness. Its awesome size and placid nature make it very difficult, if not impossible, for humans to train and manage this pongid. In zoos, the gorilla is prone to fatal pneumonia and tuberculosis, and therefore the artificial environment must be watched carefully.
Unfortunately, it is also very difficult to mate this great ape in captivity; gorillas require privacy and conditions similar to their natural habitat for sexual activity.
Fossey’s research had added to the knowledge of the gorilla diet, feeding and grooming habits, and vocalizations. Her work was an outstanding contribution to ethology. Even so, the mountain gorilla still faces the grave danger of extinction. Civilization is now slowly engulfing the shrinking wild domain of this magnificent ape. The pongid’s precarious existence is threatened by human encroachment. If serious measures are not taken, then this unique primate may vanish.
- Bright, M. (2000). Gorillas: The greatest apes. London: Toucan Books.
- Fossey, D. (2000). Gorillas in the mist. Boston: Mariner Books/Houghton Mifflin.
- Galdikas, B.M. F. (2005). Great ape odyssey. New York: Harry N. Abrams.
- Robbins, M. M., Sicotte, P., & Stewart, K. J. (Eds.) (2001). Mountain gorillas: Three decades of research at Karisoke. Cambridge, UK: Cambridge University Press.
- Schaller, G. B. (1963). The mountain gorilla: Ecology and behavior. Chicago: University of Chicago Press.
- Schaller, G. B. (1965). The year of the gorilla. New York: Ballantine.
- Vedder, A., & Weber, B. (2001). In the kingdom of gorillas: Fragile species in a dangerous land. New York: Simon & Schuster.