What Do Gorillas Eat? Gorilla Diet in the Wild

A mostly plant-based diet

Both gorilla species, the western gorilla and the eastern gorilla, are often described as herbivores, or plant-eaters. Their food falls into a few main groups:

• Leaves and shoots of herbs, shrubs and vines, the staple food of most gorillas.
• Stems and pith, the soft, juicy core of plants such as wild celery, thistles, bamboo and gingers.
• Fruit from dozens of forest trees, eaten whenever it is available.
• Bark, roots and wood, chewed or scraped especially when better food is scarce.
• Flowers, fungi and seeds in smaller amounts.

Gorillas are picky about which parts they eat. They often strip off tough outer layers to reach the tender inside of a stem, or choose young leaves over old ones, because these parts contain more protein and less fiber.

What do western lowland gorillas eat?

Western lowland gorillas, the gorillas seen in zoos, live in lowland rainforest in Central Africa and eat far more fruit than their eastern relatives. They feed on the fleshy fruits of close to a hundred seasonally fruiting tree species. When fruit is plentiful it can make up most of what they eat, and groups travel farther each day to visit fruiting trees.

When fruit runs short in the dry season, they switch to more fibrous foods: leaves, pith and stems of herbs from the arrowroot and ginger families, plus bark. In swampy areas and forest clearings called bais, they wade into water to pull up and eat aquatic plants, which are rich in minerals.

What do mountain gorillas eat?

Mountain gorillas, a subspecies of the eastern gorilla, live in cool cloud forests on the Virunga volcanoes and in Bwindi Impenetrable National Park, where fruit is scarce. In the Virunga Mountains, leaves, shoots, stems and pith make up the great majority of their diet, while fruit makes up only around 2 percent. Favorite foods include wild celery, thistles, nettles, bedstraw and bamboo shoots, which are eaten in large amounts when they sprout.

Because these plants grow almost everywhere, mountain gorillas do not have to travel far; a group often moves less than 1 km (0.6 mi) in a day. Mountain gorillas in Bwindi, at lower altitude, eat noticeably more fruit than those in the Virungas.

Grauer’s gorillas, the other eastern subspecies, eat a mix of the two patterns. Leaves and pith are staples, but fruit can make up as much as a quarter of their diet in some seasons.

Do gorillas eat insects or meat?

Gorillas do not hunt animals the way chimpanzees do. Their only regular animal food is insects. Western gorillas break open termite mounds and eat ants, and eastern gorillas also eat ants. Caterpillars and grubs are eaten occasionally, often swallowed along with leaves. These insects are a small but useful source of protein.

Gorillas also sometimes eat soil, a habit seen in many plant-eating animals. Clay may supply minerals such as sodium and help with digestion.

How much does a gorilla eat each day?

Because leaves and stems contain little energy, gorillas must eat large amounts. In a year-long study in Bwindi, adult male mountain gorillas ate an average of about 18.8 kg (41 lb) of food a day and adult females about 14.9 kg (33 lb). The Smithsonian’s National Zoo gives a similar figure of about 20 kg (45 lb) a day for adult male western lowland gorillas.

Feeding takes up much of a gorilla’s day. Gorillas typically feed for several hours in the morning, rest and digest around midday, and feed again in the afternoon before building their night nests. Their large gut, with a long colon full of microbes, helps them break down the tough plant fiber.

How do gorillas get water?

Gorillas rarely drink. Juicy plants are made up largely of water, and gorillas also lick dew from leaves, so most of their water comes from their food. They have occasionally been seen drinking from streams and pools, and western gorillas take in plenty of water when they eat aquatic plants in swampy clearings.

Why gorillas matter for the forest

By eating fruit and passing the seeds, often in a nest site where the ground is open and fertilized, western gorillas help spread the seeds of many rainforest trees. Their feeding on leaves and stems also opens up dense patches of vegetation, which lets new plants grow. Losing gorillas from a forest can therefore change which trees and plants grow there in the long term.

For a comparison with another great ape, see What do chimpanzees eat?