The diet of gorillas depends on both the environment and season they live in. For example, lowland gorillas consume an abundance of fruit while mountain gorillas may eat more green plants including shoots, stems and leaves. The gorilla’s strong teeth and massive chewing muscles allow for more effective chewing.
Gorillas are herbivorous mammals whereby they are able to survive on vegetation such as leaves, stems, roots, vines, herbs, trees, and grasses but such vegetation has relatively low nutritional quality. Therefore, they must consume a larger quantity, but it is available year-round. An adult male gorilla may consume more than 18 kg of vegetation per day. Gorillas don’t always drink water simply because they consume vegetation that has a lot of water as well as morning dew. Mountain gorillas are herbivores, feeding on plants like wild celery, thistle, and nettles about 150 various plants. Special trees are bamboo and bracket fungus. Their food plants grow profusely in the cool, moist mountain climate of their range in Rwanda, Congo and Uganda. During the rainy season because the bamboos are tender and green, the bamboo shoots contain 84% of water with an extra of trocatea, flowers, stems, roots, soft bamboo leaves as well as the dry season black berries that act as a delicacy for the mountain gorillas.
The composition of the gorilla’s diet varies by subspecies and seasonality. The Western gorilla type of subspecies can consume 97 plant species. 67% of their diet is fruit, 17% is leaves, seeds and stems and 3% is termites and caterpillars. The Eastern lowland gorilla type of subspecies consumes at least 104 plant species. Mountain gorilla type consumes at least 142 plant species and only 3 types of fruit. About 86% of their diet is leaves, shoots, and stems, 7% is roots, 3% is flowers, 2% is fruit, and 2% ants, snails, and grubs. Cross River gorilla type is not as well studied as the other subspecies. However their diet has been studied through their fecal matter and is known to include fruit, leaves, stems, piths, and some invertebrates. Western lowland gorillas eat a variety of vegetation.
While collecting their food, Gorillas use incredible strength to break vegetation. They have a choice in the food stuffs they feed on meaning that they usually eat some parts of vegetation. For example they may eat only the leaves, pith, stalk or roots of a particular plant. They use their agile lips and hand dexterity to manipulate the vegetation for the particular portion they want to consume. Gorillas do not overexploit an area for food. They crop the vegetation in a manner that allows for quick replenishment to occur.