gorilla(redirected from silverback)
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any primate of the superfamily Hominoidea, which includes humans; this article, however, focuses on the nonhuman apes. The small apes, the gibbons and the siamang, and the orangutans, which belong to the great apes, are found in SE Asia.
..... Click the link for more information. , genus Gorilla, native to the lowland and mountain forests of western and central equatorial Africa. The two gorilla species are the western, comprising the western lowland (G. gorilla gorilla) and Cross River (G. gorilla diehli) gorillas, and the eastern, comprising the eastern lowland, or Grauer's, gorilla (G. beringei graueri) and the mountain gorilla (G. beringei beringei). The Cross River gorilla of the Nigeria-Cameroon border region and the mountain gorilla of Rwanda, Congo (Kinshasa), and Uganda each number in the hundreds and are closest to extinction, but the eastern lowland gorilla and the much more numerous western lowland gorilla, with perhaps 350,000 individuals, are also considered critically endangered.
Gorillas are the largest of the apes, the males reaching a height of 5 to 6 ft (150–190 cm) with a 9-ft (144–cm) arm spread. Males weigh about 450 lb (200 kg) in the wild; in zoos they become obese and may reach 600 lb (270 kg) or more. Male gorillas have prominent sagittal crests and brow ridges and large canine teeth; these features are less developed in females. Females are smaller than males, weigh about half as much, and do not develop the gray hair on the back characteristic of the sexually mature male. Females bear one infant about every four years; the child is carried in the mother's arms and then on her back. Females mature in 8 or 9 years, males in 11 or 12; gorillas may live more than 40 years.
Dominant older males, called silverbacks, usually lead stable harem societies of 2 to 30 females and juvenile males in a daily search for food. The animals normally walk on all fours, resting their upper body on their knuckles. They are vegetarians, living on a variety of vines, leaves, fruit, roots, and bark. Mountain gorillas eat wild celery, bamboo shoots, nettles, thistles, and sometimes certain soils or a rare form of fungus. Adolescents and small females may climb trees in search of food and to build arboreal nests for sleeping. Adults of both sexes build ground nests daily.
Quiet and retiring in temperament when compared to the excitable chimpanzeechimpanzee,
an ape, genus Pan, of the equatorial forests of central and W Africa. Smaller populations are also found in the savannas of the same regions. The common chimpanzee, Pan troglodytes, lives N of the Congo River.
..... Click the link for more information. , gorillas have been known to attack humans in defense of their family group. Gorillas normally rely on bluffs, roaring and beating their chests to frighten intruders. Their main enemies are human poachers; in the lowlands, leopards may sometimes eat the young. Disease and deforestation are also serious threats.
Gorillas are classified in the phylum ChordataChordata
, phylum of animals having a notochord, or dorsal stiffening rod, as the chief internal skeletal support at some stage of their development. Most chordates are vertebrates (animals with backbones), but the phylum also includes some small marine invertebrate animals.
..... Click the link for more information. , subphylum Vertebrata, class Mammalia, order Primates, family Hominidae.
See D. Fossey, Gorillas in the Mist (1983); J. Shreeve, Nature: The Other Earthlings (1987).
(Gorilla gorilla), the largest ape, a member of the family Pongidae of the order Primates.
The adult male grows to a height of 175 cm, with an arm spread of up to 260 cm, a chest girth of up to 152 cm. and a weight of from 135 to 180 kg (in captivity, up to 300 kg). The females are much smaller, weighing 75–110 kg (up to 126 kg in captivity). The hair is black and on the top of the head, chestnut-colored; with age it turns gray along the back. The head is large, with a markedly protruding forehead. The trunk is massive, and the upper limbs are longer than the lower ones. Similarities in body construction to that of humans are partially explained by the gorilla’s terrestrial way of life. The volume of the cranium is 500–600 cu cm (up to 752 cu cm), and the brain is similar in construction to that of a human. There are 48 chromosomes.
Gorillas are found in Equatorial Africa. There are three subspecies: the western lowland gorilla, the eastern mountain gorilla, and the eastern lowland gorilla, the last two being larger than the first. They live in tropical or mountain forests and in small herds (of five to 30 individuals) led by powerful males. On the ground they move on all fours. Sometimes they climb trees. They are herbivorous, eating fruits, berries, and nuts. At night they live in nests built on the ground or in trees. The gestation period is from 250 to 290 days: the newborn gorilla weighs about 2 kg. Longevity in the wild is 25–30 years. As a result of sport hunting, their numbers have been greatly reduced, and they are now protected. They do not thrive in captivity and rarely reproduce.
REFERENCESSchaller. G. B. God pod znakom gorilly. Moscow, 1968. (Translated from English.)
Napier, J. R., and P. H. Napier. A Handbook of Living Primates. London-New York, 1967.
M. F. NESTURKH