The Omnivorous Nature of Some Monkeys
The popular image of monkeys often involves them happily munching on bananas, suggesting a strictly plant-based diet. This common perception, however, does not fully capture the diverse eating habits of these primates. While many monkey species primarily consume plant matter like fruits, leaves, nuts, and seeds, a significant number also supplement their diet with animal protein, making them omnivores.
Omnivory in primates allows them to adapt to various environments and access a broader range of nutrients. Meat eating is often an opportunistic behavior, meaning monkeys will consume animal protein when the chance arises, rather than relying on it as a primary food source for most species. A review of over 400 studies found that 12 out of 16 monkey families, encompassing 89 species, engage in meat eating. This shows it’s a widespread, though often secondary, dietary strategy among monkeys.
Specific Species and Their Prey
While many primates consume insects, which are a form of animal protein, some species actively hunt and eat larger prey. Chimpanzees, though apes, are well-known for their meat-eating habits and often associated with monkeys by the public. They are skilled hunters, preying on a diverse array of animals, including red colobus monkeys, infant baboons, bush babies, and even small antelopes. Male chimpanzees frequently cooperate in hunting expeditions, and successful hunters often share their catch with other group members.
Baboons are another prominent example of omnivorous primates that consume meat. These adaptable monkeys prey on more than 21 different mammal species, including fish, eggs, snakes, hares, and young antelopes or sheep. Their opportunistic nature means they will also consume birds and rodents. Capuchin monkeys, found in the Americas, exhibit a varied diet that includes raiding nests for bird eggs and preying on small mammals like squirrels and coatis, as well as frogs and lizards.
Smaller monkey species, such as marmosets and tamarins, also incorporate animal protein into their diets. These callitrichids, native to South America, primarily consume insects but will also hunt and eat snails, spiders, frogs, and small lizards. Other Old World monkeys like vervet monkeys, macaques, and mandrills also include reptiles and amphibians in their diet. This wide range of prey highlights the diverse ways different monkey species acquire animal protein.
Drivers of Meat Consumption
The inclusion of meat in the diet of many monkey species is driven by several factors, primarily nutritional benefits. Meat provides a concentrated source of protein and fat, offering essential nutrients that are often scarce in plant-based foods. This high energy and nutrient density can be particularly valuable for activities requiring significant energy, such as brain development and reproductive success. Animal tissues also contain specific micronutrients like vitamin B12, which are rarely found in wild plants.
If an easy opportunity arises, such as finding eggs or a vulnerable small animal, they will take advantage of it. While some species, like chimpanzees, engage in coordinated hunting, for many others, meat is a supplemental food item rather than a consistently hunted resource.
Environmental factors also influence dietary choices. The availability of resources in different habitats can dictate what food sources are accessible to monkeys. When preferred plant foods are scarce, animal protein can serve as an alternative.