“Gorillas share about 98 percent of their DNA with humans.”
Western gorillas move through Central African forests in social groups usually led by a mature silverback. They feed mainly on fruit, leaves, and stems, build fresh sleeping nests, and remain Critically Endangered as habitat loss, hunting, and disease reduce wild populations.
By An Nguyen · Published · Updated
Gorilla gorillaPrimatesHominidae
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Core article
A closer look at habitat, diet, behavior, reproduction, and conservation.
Gorillas are the largest living primates and inhabit tropical and swamp forests in equatorial Africa. This profile focuses mainly on the western lowland gorilla (Gorilla gorilla gorilla), which feeds on fruit, leaves, stems, and other plant material. Most live in groups led by a mature silverback, with daily activity centered on foraging, resting, travel, and care of young. Gorillas share approximately 98 percent of their DNA with humans, reflecting their place within the great-ape family.
Gorillas belong to the kingdom Animalia, phylum Chordata, class Mammalia, and order Primates. Their family is Hominidae, which also includes chimpanzees, orangutans, and humans. The genus Gorilla contains two recognized species: the western gorilla (Gorilla gorilla) and eastern gorilla (Gorilla beringei). The measurements and range on this page primarily describe the western lowland gorilla, a subspecies of the western gorilla.
Evolutionary estimates place the divergence of the gorilla lineage from the common ancestor shared with humans and chimpanzees about 7 to 9 million years ago, during the late Miocene. Climatic shifts altered African habitats during this period. The gorilla lineage developed robust cranial anatomy for processing tough vegetation and locomotor traits suited to terrestrial life in the forest.
Gorillas show marked sexual dimorphism. Adult males, called silverbacks after the gray-white hair that develops across the back and hips, are larger than females. A mature silverback typically stands 4.5 to 5.5 feet tall when upright, has a body length up to 6 feet, and weighs 300 to 440 pounds. Females generally weigh 150 to 250 pounds.
Gorillas can reach up to 25 mph in short ground bursts. Their usual form of locomotion is knuckle-walking, in which the upper body is supported on the dorsal surface of the middle finger bones. This leaves the opposable thumbs and fingers available for handling food and grooming.
Adult males have a prominent sagittal crest that anchors the temporalis muscles used to process coarse plant material. Broad, relatively flat molars grind leaves and stems. Their long arms, often spanning wider than their height, help with locomotion and breaking vegetation, while thick hair provides insulation in damp forest conditions.
Western gorillas occur in equatorial forests of Central and West Africa, including Gabon, the Republic of the Congo, Cameroon, the Central African Republic, Equatorial Guinea, Nigeria, and Angola. Western lowland gorillas use lowland tropical forest and swamp forest.
These forests receive high annual rainfall and support diverse plant communities. Swamp forests add aquatic and semi-aquatic vegetation to the seasonal diet. Gorillas spend most of their time on the ground, although females and juveniles climb more often to forage or play. Forest vegetation supplies food, nesting material, and cover.
West and Central African forests also support the mandrill, a smaller ground-foraging primate with a different social and feeding ecology.
Gorillas feed mainly on low-calorie, fibrous plant material. An adult silverback can consume dozens of pounds of vegetation in a day. The exact diet varies by season and location and can include hundreds of plant species, with leaves, pith, stems, and shoots forming much of the daily intake.
When fruit is available, gorillas may eat more of it. Their hands strip bark to reach cambium, while large molars and jaw muscles process bamboo shoots and fibrous stalks. Small insects and grubs may be swallowed with vegetation but form a minor part of the diet. Foraging occupies much of the day and is interspersed with rest and social activity.
Gorillas live in groups often called troops or bands. A typical group contains 5 to 30 individuals and is usually led by a mature silverback. The silverback mediates conflicts, influences travel and foraging routes, and defends the group from rival males and predators such as leopards.
Group members communicate through vocalizations, postures, and facial expressions. Chest beating, hooting, vegetation pulling, and short charges can signal status or deter a rival without direct contact.
Reciprocal grooming removes debris and helps maintain social bonds. When a new silverback replaces a resident male, he may kill dependent infants, after which females can return to estrus. Gorillas construct sleeping nests from branches and leaves, usually making a new nest each evening on the ground or in low branches.
Gorillas mature and reproduce slowly. Females reach sexual maturity around 10 to 12 years of age, while males mature later. After a gestation of approximately 8.5 months, a female usually gives birth to one infant; twins are rare.
A newborn weighs about 4 pounds and depends on its mother for food and transport. It first clings to her underside and later rides on her back. Nursing often lasts 3 to 4 years, during which the infant learns foraging and social behavior by observing other group members.
Female gorillas typically give birth once every 4 to 6 years. This interval limits how quickly a population can recover after losses. Wild gorillas commonly live 35 to 40 years, while individuals in human care can live 50 years or more.
(Population and conservation trend data sourced from the IUCN Red List of Threatened Species)
The western gorilla is classified as Critically Endangered by the International Union for Conservation of Nature (IUCN), with a decreasing population trend.
Logging, agriculture, and mining clear and fragment tropical forest habitat. Fragmentation separates groups, limits movement, and can reduce genetic exchange between populations.
Logging roads can also increase access for hunters involved in the illegal bushmeat trade. Gorillas are susceptible to diseases transmitted by humans and other primates, and Ebola outbreaks have caused large local declines. Conservation work includes anti-poaching patrols, habitat protection, health monitoring, and community-based tourism programs.
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Primates
Family
Hominidae
Genus
Gorilla
Species
G. gorilla
Gorillas share about 98 percent of their DNA with humans.
A dominant male gorilla is called a silverback because of the gray hair on his back.
Gorillas build a new leafy nest to sleep in almost every night.
Adult gorillas eat dozens of pounds of vegetation each day.
Gorillas usually beat their chests to warn rivals, not to start a fight.
Infants learn by watching mothers and other troop members.
Select a question to reveal the answer.
A gorilla is a large ape that lives in African forests. Gorillas are plant-eaters and live in family groups called troops.
Western lowland gorillas live in tropical forests and swampy lowlands in central and western Africa.
Gorillas are mostly herbivores. They eat leaves, stems, fruit, and other forest plants.
Gorillas are usually calm, but a silverback will defend his troop if he feels threatened. Wild gorillas should never be approached.
Yes. Western gorillas are listed as Critically Endangered because of habitat loss, disease, and hunting.
Gorillas live in troops led by one dominant silverback male, along with females and young gorillas.
Gorillas are great apes and are closely related to humans and chimpanzees.
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