The silverback gorilla is the mature adult male of the species, distinguished by a saddle of silvery-gray hair extending across his back and hips, a sign of full maturity. These powerful primates, which can weigh up to 430 pounds, lead family groups in the tropical and subtropical forests of Central Africa. Their massive size requires a tremendous amount of energy, sustained by an overwhelmingly herbivorous diet. While the specific components vary between Mountain, Western, and Eastern Lowland Gorillas, their nutritional strategy revolves around consuming vast quantities of forest vegetation.
Primary Food Sources
The majority of a silverback’s diet consists of fibrous, green plant matter, necessary for sustaining their large body mass. Leaves, stems, pith, and shoots form the backbone of their daily caloric intake, though the specific percentage varies by subspecies and habitat. Mountain Gorillas, residing in high-altitude forests where fruit is scarce, rely most heavily on this vegetative diet. For them, leaves and stems can make up over 90% of their food, including plants like wild celery, nettles, and thistles.
Gorillas prefer young, tender leaves and the pith—the soft, inner core—of plant stems, which are often richer in protein and moisture than mature foliage. Their large digestive tract efficiently breaks down the tough cellulose found in this vegetation. While Western Lowland Gorillas inhabit forests with more fruit trees, green plant material remains the largest portion of their diet. Consuming this diverse array of tough plants ensures the silverback has a stable food supply year-round.
Secondary and Supplemental Foods
Silverbacks consume a range of foods opportunistically or seasonally to supplement their nutritional needs. Fruit consumption is the most significant differentiator between subspecies, providing a quick energy boost from natural sugars. Western and Eastern Lowland Gorillas incorporate more fruit, such as figs and African breadfruit, into their diet when available, sometimes reaching up to 25%. Mountain Gorillas consume fruit far less frequently due to its scarcity in their high-altitude environment.
Tree bark and roots are sought out, especially when preferred foods are less abundant. Bark provides essential minerals like calcium and sodium, while roots and tubers offer micronutrients and starches. Small invertebrates, including termites, ants, and larvae, serve as a minor source of protein and fat. These are often consumed accidentally or deliberately while foraging and constitute a very small percentage of the overall diet, typically less than 3%.
Feeding Behavior and Water Intake
A silverback must eat an immense quantity of food daily, consuming between 40 and 60 pounds of vegetation. As the group leader, the silverback guides the troop to optimal foraging areas, often spending nearly half the daylight hours eating. They are highly selective foragers, using dexterity to choose only the most nutritious parts of a plant.
For example, they may strip leaves from a stem or use their strength to shred the outer layer of a plant to reach the soft, nutrient-rich pith inside. Silverbacks rarely need to drink freestanding water. They obtain sufficient hydration from the high moisture content of their diet, as their preferred succulent plants are often comprised of nearly 50% water. This moisture, supplemented by morning dew, means they seldom visit streams or water bodies.