Gorillas
Gorillas (Gorilla gorilla) inhabit the forests of Central Africa and are the largest and most powerful of all primates. Adult males stand 6 ft (1.8 m) upright (an unnatural position for a gorilla) and weigh up to 450 lb (200 kg), while females are much smaller. Gorillas live to about 44 years and mature males (those usually over 13 years), or silverbacks, are marked by a band of silver-gray hair on their backs.
Gorillas live in small family groups of several females and their young, led by a dominant silverback male. The females comprise a harem for the silverback, who holds the sole mating rights in the troop. Like humans, female gorillas produce one infant after a gestation period of nine months. The large size and great strength of the silverback are advantages in competing with other males for leadership of the group and in defending the group against outside threats.
During the day these ground-living apes move slowly through the forest, selecting species of leaves, fruit, and stems from the surrounding vegetation. Their home range is about 9–14 mi2 (25–40 km2). At night the family group sleeps in trees, resting on platform nests that they make from branches; silverbacks usually sleep at the foot of the tree.
Gorillas belong to the family Pongidae (which includes chimpanzees Pan], orangutans [Pongo pygmaeus], and gibbons [genus Hylobates). Together with chimpanzees, gorillas are the animal species most closely related to man. Like most megavertebrates, gorilla numbers are declining rapidly and only about 40,000 remain in the wild. There are three subspecies, the western lowland gorilla (G. g. gorilla), the eastern lowland gorilla (G. g. graueri), and the mountain gorilla (G. g. beringei). The rusty-gray western lowland gorillas are found in Nigeria, Cameroon, Equatorial Guinea, Gabon, Congo, Angola, Central African Republic, and Zaire (now Democratic Republic of the Congo [DRC]). The black-haired eastern lowland gorillas are found in eastern DRC. Deforestation and hunting now threaten lowland gorillas throughout their range.
The mountain gorilla has been intensely studied in the field, notably by George Schaller and Dian Fossey, upon whose life the film Gorillas in the Mist is based. This endangered subspecies is found in the misty mountains of easternZaire, Rwanda, and Uganda at altitudes of up to 9,000 ft (3,000 m) and in the Impenetrable Forest in southwest Uganda. Field research has shown these powerful primates to be intelligent, peaceful and shy, and of little danger to humans.
A silverback male gorilla. (Photograph by Jerry L. Ferrara. Photo Researchers Inc. Reproduced by permission.)
Other than humans, gorillas have no real predators, although leopards will occasionally take young apes. Hunting, poaching (a mountain gorilla is worth $150,000), and habitat loss are causing gorilla populations to decline. The shrinking forest refuge of these great apes is being progressively felled in order to accommodate the ever-expanding human population. Mountain gorillas are somewhat safeguarded in the Virunga Volcanoes National Park in Rwanda. Their protection is funded by strictly controlled small-group gorilla-viewing tourist experiences that exist alongside long-term field research programs. Recent population estimates are 10,000–35,000 (with 550 in captivity) western lowland gorillas, 4,000 (with 24 in captivity) eastern lowlands gorillas, and 620 mountain gorillas.
Resources
Books
Fossey, D. Gorillas in the Mist. Boston: Houghton Mifflin, 1983.
Schaller, G. B. The Mountain Gorilla: Ecology and Behavior. Chicago: University of Chicago Press, 1988. ———. The Year of the Gorilla. Chicago: University of Chicago Press, 1988.
Other
The Dian Fossey Gorilla Fund International. [cited May 2002]. <http://www.gorillafund.org/000_ core_frmset.html>.
Gorilla Aid. [cited May 2002]. <http://www.gorillaaid.org E;.
This is the complete article, containing 573 words
(approx. 2 pages at 300 words per page).
