The four recognized gorilla subspecies—Mountain, Cross River, Western Lowland, and Eastern Lowland gorillas—are the largest primates on Earth. Their immense size often leads to the misconception that they are fierce predators capable of taking down large prey. This raises the common question of whether these powerful animals hunt smaller monkeys that share their forest habitats. Understanding the gorilla’s true nature requires examining their specialized diet, which is dictated by their massive physical requirements and ecological niche.
The Definitive Answer: Gorilla Predation
Gorillas are characterized as herbivores, meaning their diet is almost entirely plant-based. Active, strategic hunting of complex prey like monkeys is not a characteristic behavior of any gorilla subspecies. Their digestive systems and social behaviors are not adapted for pursuing and consuming large animal protein.
Reports of gorillas consuming mammal meat are exceptionally rare and fall under opportunistic feeding rather than true predation. While DNA from monkeys and small forest antelopes (duikers) has been detected in gorilla feces, researchers suggest this is likely due to indirect ingestion. Gorillas may consume insects, such as ants, that have scavenged on mammal carcasses, leading to the presence of mammal DNA in their digestive tract.
A Diet Rooted in Plants
The gorilla’s enormous body mass is sustained by a high-volume diet of vegetation, accounting for the vast majority of their caloric intake. An adult male gorilla can consume over 18 kilograms (40 pounds) of plant matter daily to meet its energy needs. The specific types of plants eaten vary based on the subspecies and its habitat.
Mountain Gorillas, who live in high-altitude forests, are primarily folivores, or leaf-eaters. Their diet consists mainly of tough, fibrous material like leaves, stems, pith, and shoots, including bamboo and wild celery. They consume a very small percentage of fruit, which is scarce in their environment.
Western Lowland Gorillas, which inhabit swampy and lowland forests, are more frugivorous. Their diet incorporates a greater amount of seasonal fruit, though leaves and other plant parts remain a substantial component. Both subspecies are selective foragers, often eating only specific parts of a plant, such as a tender pith or root.
The Importance of Insect Protein
The closest a gorilla comes to consuming meat is through entomophagy, or insect eating. This minor, non-plant consumption provides a valuable supplemental source of protein, vitamins, and minerals difficult to acquire solely from vegetation. Western Lowland Gorillas, in particular, commonly forage for ants and termites.
They use specialized techniques to acquire these insects, such as stripping bark to find larvae or accessing termite mounds. Gorillas are selective about the insects they consume, sometimes choosing termite species high in iron and ash content. This insect intake is a consistent part of the diet and represents the only documented animal matter regularly eaten in the wild.
Hunting Behavior Compared to Chimpanzees
When examining predatory behavior among great apes, gorillas stand in stark contrast to chimpanzees. Chimpanzees are opportunistic omnivores who actively organize coordinated hunts for prey, including various species of monkeys. This difference is rooted in the distinct behavioral ecology and physical adaptations of the two species.
Gorillas are built for strength and stability, spending most of their time grazing on bulk vegetation on the forest floor. Their social structure is typically peaceful and focused on foraging. Chimpanzees are smaller, more agile, and possess a social structure that supports complex group coordination for hunting. They rely on speed and teamwork, a tactic for which the gorilla’s physique is not suited.