Chimpanzees are classified as omnivores, meaning their diet naturally includes both plant and animal matter. This classification is often surprising because the overwhelming majority of their nutritional intake comes from plant-based sources. Animal protein makes up a small percentage of their total diet but provides essential nutrients, such as certain amino acids and B vitamins, that are difficult to obtain from plants alone. Their foraging and hunting strategies reflect an adaptation to maximize the acquisition of both energy-rich plant foods and protein-dense animal resources.
The Foundation of the Chimpanzee Diet
The daily diet of a wild chimpanzee is predominantly composed of vegetation, often making up over 90% of their total food intake. This vast amount of plant material leads many to mistakenly believe chimpanzees are herbivores. Fruits are the preferred and most substantial component of this plant-based diet, especially ripe, sugary varieties that provide easily digestible energy and calories.
When ripe fruit is abundant, chimpanzees may spend significant time on just a few preferred species, such as figs, which contribute lipids and carbohydrates. They also consume an enormous variety of other plant parts, with some populations eating food items from hundreds of different plant species. This diversity includes young leaves, leaf buds, flowers, seeds, and pith (the soft, inner tissue of certain plant stems).
Chimpanzees rely on tougher plant matter as a fallback food when preferred fruits are scarce, particularly during dry seasons. They consume nuts, sometimes cracking them open using tools like stones, and they chew on bark. This ability to switch between energy-dense fruits and high-fiber vegetative parts ensures they can maintain their nutritional needs throughout seasonal fluctuations.
Essential Protein Sources: Insects and Opportunistic Prey
To supplement their largely plant-based diet, chimpanzees consistently seek out invertebrates, which provide a concentrated source of protein, fat, and micronutrients like Vitamin B12. Insects, particularly termites and ants, are a staple that is small in volume but significant in nutritional value. Termite fishing is a well-documented behavior where chimpanzees modify flexible tools, such as twigs or grass stems, to probe into termite mounds or nests.
The complexity of tool use varies, with some communities using a specialized “tool set” to harvest army ants. They select specific plant materials, like the shoots of Alchornea hirtella, for their suitability for “ant-dipping.” This technique allows them to safely collect a substantial meal of insects that might otherwise be too aggressive or difficult to handle individually.
Beyond insects, chimpanzees opportunistically consume small vertebrates and their products, which provide additional high-quality protein. This includes bird eggs and occasionally small reptiles or amphibians encountered during foraging. The search for these small animal foods is typically a solitary activity, distinct from the social behavior involved in hunting larger prey.
Coordinated Hunting and Meat Consumption
Chimpanzees engage in complex, coordinated hunting of medium-sized mammals, a behavior first observed by Jane Goodall. Although meat makes up a small fraction of their overall diet, often less than 2%, it is a highly valued and intensely sought-after resource. Their preferred prey are often other primates, such as red colobus monkeys, which they pursue through the forest canopy.
These hunts are highly social events, frequently involving male chimpanzees acting in concert to strategize and capture the agile prey. The cooperative effort is sophisticated, with different individuals taking on specialized roles. These roles include “drivers” who chase the monkey, “blockers” who cut off escape routes, and “captors” who make the final kill. Vocalizations, such as a specific “hunting bark,” are sometimes used to recruit more group members and increase the effectiveness of the chase.
Successful capture results in the sharing of meat, which is not only a nutritional exchange but also carries significant social weight within the community. Dominant males who participate in the hunt often control the distribution of the meat. The act of sharing can solidify social bonds and influence political standing. This cooperative predation, which requires communication and division of labor, demonstrates a level of dietary complexity far beyond that of a vegetarian species.