Gorillas, the largest living primates, primarily consume plant-based foods in their natural habitats. Understanding their diet offers insights into their biology and the ecosystems they inhabit across central and eastern Africa. These powerful herbivores adapt their eating habits to the diverse vegetation available. Their specific foods vary based on location and seasonal availability, but plant material consistently forms the vast majority of their daily intake.
The Primary Plant-Based Diet
A gorilla’s diet consists predominantly of various plant parts. They consume large quantities of leaves, stems, pith, bark, and roots. This fibrous vegetation provides the bulk of their nutrition, forming over 85% of their diet for some species. For instance, mountain gorillas rely heavily on herbaceous plants like thistles, nettles, wild celery, and bamboo shoots.
Gorillas are selective foragers, often choosing specific parts of a plant. They use their strength to break apart vegetation, such as shredding a banana tree to access its tender inner pith. An adult male gorilla can consume 18 to 30 kilograms (40 to 66 pounds) daily. This high volume of plant intake also provides most of the water gorillas need, meaning they rarely drink directly from water sources.
Fruits and Other Occasional Foods
Fruits serve as a highly desired, though seasonal, part of the gorilla diet. When available, fruits like berries, bananas, guavas, figs, papayas, plums, and cherries are consumed. Fruit availability fluctuates, leading gorillas to adjust their diet to more readily available fibrous plants during leaner periods.
Gorillas also supplement their plant-based diet with small amounts of other items. Insects, such as ants, termites, grubs, and larvae, make up less than 1-2% of their total food intake. These small animal protein sources are obtained opportunistically; for example, Western lowland gorillas break open termite nests to consume the larvae. Occasionally, gorillas ingest soil or mineral licks, which may provide essential minerals or help neutralize potential toxins.
Dietary Differences by Gorilla Species
The specific composition of a gorilla’s diet varies considerably among different species, influenced by habitat and food availability. Western gorillas, including Western lowland and Cross River gorillas, consume more fruit when it is abundant in their lowland forest environments. For Western lowland gorillas, fruit can constitute a significant portion, sometimes up to 67%, of their diet. These gorillas also have a broader range of plant species, consuming around 97 to 200 different plant types.
Eastern gorillas, which include mountain gorillas and Eastern lowland (Grauer’s) gorillas, rely more heavily on fibrous vegetation. Mountain gorillas, living at higher altitudes where fruit is scarce, have a diet composed primarily of leaves, shoots, and stems, accounting for about 86% of their intake. Fruit makes up only about 2% of their diet due to limited availability. Their food range is also more restricted, often consuming between 38 and 142 different plant species.