Gorilla
Gorilla gorilla gorilla
Gorilla: Congo Basin's Knuckle-Walking Silverback
Wilder's Gorilla card is the western lowland gorilla (Gorilla gorilla gorilla), the most widespread gorilla subspecies. These Critically Endangered great apes live in Central African lowland and swamp forest in family groups led by a silverback.
- Habitat
- Lowland tropical and swamp forest
- Size
- Males ~136 kg, up to ~1.8 m; females smaller
- Diet
- Fruit, leaves, stems, bark; some insects
- Range
- Congo Basin: Cameroon to Angola/Cabinda
- Conservation
- Critically Endangered (IUCN)
- Family
- Hominidae (great apes), with chimpanzees
Habitat & range
This card covers the western lowland gorilla (Gorilla gorilla gorilla), the usual zoo and media form and the most widespread gorilla subspecies. It lives in lowland tropical rainforest, swamp forest and forest clearings across Cameroon, the Central African Republic, Equatorial Guinea, Gabon, the Republic of Congo and Angola (Cabinda), mostly below about 800 m (IUCN Red List; Smithsonian National Zoo). Home ranges are often measured at roughly 9 to 14 square miles (about 15 to 23 km2). Groups usually travel less than 1.6 km (1 mile) a day, farther when fruit is abundant. Because of their size, adults spend most of their time on the ground (Smithsonian National Zoo).
Size & appearance
Gorillas are the largest living primates. Western lowland gorillas are the smallest gorilla subspecies, but adult males still average about 136 kg (300 lb) and can stand about 1.8 m (6 ft) tall, with an arm span around 2.4 m (8 ft). Females average much smaller, roughly 70 to 90 kg and about 1.4 m tall (Smithsonian National Zoo). The coat is dark brown-black to black; the face, ears, hands and feet are bare jet-black skin. Mature males, called silverbacks, grow a silver-grey saddle across the lower back that in westerns often extends onto the rump and thighs, plus a tall bony sagittal crest that makes the head look conical (Smithsonian National Zoo; Columbus Zoo). They knuckle-walk: weight rests on the curled knuckles of the long arms.
Diet & social life
Western lowland gorillas are mainly herbivores. They eat leaves, stems, pith, bark and especially fruit from many seasonal tree species, plus small invertebrates found on plants. An adult male can eat about 20 kg (45 lb) of food a day (Smithsonian National Zoo; IFAW). They live in family groups led by a dominant silverback. Western groups often split up during the day to forage and come back together at night to build fresh nests from vegetation (Gorilla Organization). Infants have a small white rump tuft that fades by about four years of age (Smithsonian National Zoo).
Conservation
The IUCN lists the western lowland gorilla as Critically Endangered (criteria A4bcde, assessed 2016). Numbers have fallen by more than 60 percent over about 20 to 25 years because of commercial bushmeat hunting, Ebola outbreaks and logging that opens forest to hunters (IUCN Red List; Smithsonian National Zoo). They still occupy a huge forest footprint, on the order of 700,000 km2, but the downward trend is steep. Cross River gorillas (Gorilla gorilla diehli), the other western subspecies, are even rarer and more fragmented (IUCN Red List).
Fun facts about Gorilla
- Each gorilla has a unique nose print, like a fingerprint (Smithsonian National Zoo).
- Adult males turn silver around 12 to 13 years old but do not reach full size until about 15 (Columbus Zoo).
- Western lowland gorillas eat more fruit than eastern gorilla subspecies when it is available (Gorilla Organization).
- Arms are longer than legs, so knuckle-walking is their main way of getting around on the ground (Smithsonian National Zoo).
- They share Central African forests with chimpanzees in places, but serious fighting between the two apes has not been recorded at study sites (Wisconsin National Primate Research Center factsheet).
Gorilla vs Grizzly Bear
The grizzly wins on size and claws; they never meet in nature.
These two would never meet in the wild: western lowland gorillas live in Central African forests (IUCN Red List; Smithsonian National Zoo), while grizzly bears (Ursus arctos) live in North America and parts of Eurasia (Animal Diversity Web). The matchup is a fun who-would-win pairing, not a real encounter. In that made-up clash, the silverback brings huge arm strength, a powerful bite and a chest-beat threat display. The grizzly brings greater mass, long claws and a predatory lifestyle. Our verdict: the bear's size and weapons win on the ground.
Read more about Grizzly Bear.
Common questions about Gorilla
Why is a male gorilla called a silverback?
Mature males grow a silver-grey saddle of hair across the lower back (often onto the rump and thighs in western lowland gorillas). That colour pattern is why older males are called silverbacks (Smithsonian National Zoo; Columbus Zoo).
Are western lowland gorillas endangered?
Yes. The IUCN lists them as Critically Endangered. Their numbers fell by more than 60% over about 20–25 years from bushmeat hunting, Ebola and logging (IUCN Red List; Smithsonian National Zoo).
How big is a western lowland gorilla?
Adult males average about 136 kg (300 lb) and can stand about 1.8 m (6 ft) tall, with an arm span around 2.4 m. Females are much smaller, roughly 70–90 kg and about 1.4 m tall (Smithsonian National Zoo).
What is the difference between western lowland and mountain gorillas?
Western lowland gorillas (Gorilla gorilla gorilla) live in Central African lowland and swamp forest; mountain gorillas (Gorilla beringei beringei) are an eastern species of cooler highland forests, with longer hair. Western lowlanders are the smallest and most widespread gorilla subspecies (IUCN Red List; Smithsonian National Zoo).
Do gorillas eat meat?
Almost never as hunters. Western lowland gorillas are mainly herbivores—fruit, leaves, stems and bark—plus small invertebrates found on plants. An adult male can eat about 20 kg (45 lb) of food a day (Smithsonian National Zoo). Compare the chimpanzee, which eats more animal prey.
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