Quick Answer
Gorillas are classified as herbivores, meaning they eat a plant-based diet. While gorillas in the wild occasionally consume small insects for added protein, their digestive systems are not adapted to handle large quantities of meat. Gorillas lack the sharp teeth and short digestive tracts of true omnivores and carnivores. However, in captivity, gorillas have been known to eat small amounts of meat, eggs, and dairy provided by caretakers without ill effects. Overall, the consumption of meat and other animal products is not part of the natural gorilla diet.
Gorilla Diet in the Wild
Gorillas are the largest living primates and reside in the forests and jungles of central sub-Saharan Africa. Wild gorillas are folivores, meaning the main part of their diet consists of leaves, stems, and stalks of plants. It is estimated that half to two-thirds of a wild gorilla’s diet is made up of foliage. Gorillas also feed on roots, vines, barks, flowers, fruits, and seeds depending on availability within their habitat.
The western lowland gorilla resides in tropical and subtropical forests spread across seven countries in western Africa. Their habitat provides them with a wide variety of vegetation including figs, celery, thistles, legumes, herbs, and various fruits. The mountain gorilla is found at high elevations in just two isolated mountain rainforests within central Africa. The cooler high altitude environment produces thick bamboo as their primary food source along with leaves, vines, and flowers. The eastern lowland or Grauer’s gorilla inhabits the dense tropical and subtropical rainforests on the eastern side of central Africa’s mountain range. Their main diet consists of juicy fruit abundant in the lowland forests along with pith and tree bark.
The diverse vegetarian diet of wild gorillas provides them with sufficient nutrients and energy to support their large body size and active lifestyles. Male gorillas can reach over 400 pounds while females are often half that size. Gorillas spend most of their day foraging and feeding on vegetation. The bulk fibrous nature of their herbivorous diet means gorillas must eat frequently throughout the day to take in adequate calories. Gorillas spend about half their day feeding, slowly and steadily making their way through the forest munching leaves, shoots, and fruits.
While classified as herbivores, wild gorillas will occasionally supplement their diet with protein-rich insects. Termites and ants contain essential amino acids absent in an exclusively herbivorous diet. When available, gorillas appear to seek out and consume termites and ants enthusiastically. However, these insect snacks make up a very small percentage of their total caloric intake.
Key Takeaways:
- Wild gorillas are primarily herbivores, feeding on leaves, stems, shoots, barks, roots, and fruits of available vegetation.
- The exact composition of gorilla diets varies by subspecies and geographic location.
- Gorillas may supplement their herbivorous diets with small amounts of insects like termites and ants for additional protein.
Do Wild Gorillas Eat Meat?
There are no verified reports of wild gorillas actively hunting for meat. As herbivores, gorillas do not have the instincts, digestive system, or teeth adapted for a carnivorous diet. However, there are anecdotal reports of gorillas possibly eating meat under very rare circumstances. Stories exist of mountain gorillas eating the discarded remains of antelope or other small prey hunted by leopards in their shared habitat. There are also reports from early European explorers in Africa witnessing gorillas feeding on dead elephants.
While intriguing, these reports lack scientific documentation and almost certainly describe aberrant singular incidents. No photographs or physical evidence exists of wild gorillas intentionally and regularly consuming meat or hunting prey. These sparse anecdotal accounts likely represent curious gorillas sampling meat opportunistically rather than any deliberate effort to hunt or eat flesh.
It is theorized that the high fiber gorilla diet may result in protein cravings that could motivate this sort of meat sampling behaviors on very rare occasions. However, without confirmation, it remains speculative whether wild gorillas actively seek out animal flesh to eat, even in miniscule amounts, absent extreme circumstances. Captive gorillas are known to enthusiastically eat eggs, cheese, yogurt and other animal proteins when available, supporting this protein craving theory.
Key Takeaways:
- There are no definitive recorded observations of gorillas actively hunting prey or eating flesh in the wild.
- Rare anecdotal accounts suggest gorillas may sample meat opportunistically in unique cases.
- Gorillas lack adaptations for digesting meat and hunting prey seen in true omnivores.
Gorilla Digestive System
The gorilla digestive system provides further evidence for their herbivorous status. As hindgut fermenters, gorillas have an enlarged cecum adapted to a high-fiber, plant-based diet. Gorillas only have one stomach compartment compared to four-chambered stomachs in many grazing herbivores. Long intestines allow time and microbial action to break down and absorb the cellulose in leaves, stems, and shoots.
In contrast, carnivores and omnivores have shorter, less specialized digestive tracts to quickly process and eliminate chunks of meat before bacteria multiply. The highly acidic stomach acid in meat eaters is strong enough to kill bacteria as well as break down protein. Gorilla stomach acid has a pH between 5 and 7, significantly weaker than carnivore acid with a pH close to 1.
Gorilla teeth also reflect their herbivorous status. They have large molars well suited for grinding fibrous vegetation. Their pronounced incisors form a diamond shape on their lower jaw useful for stripping vegetation. In comparison, carnivores have dagger-like incisors and fangs adapted for killing prey along with teeth suited for cutting meat, absent in gorilla dentition.
Key Takeaways:
- Gorillas have an enlarged cecum and long intestinal tract to allow microbial fermentation of plant matter.
- In comparison, carnivores have much shorter digestive systems adapted for rapid meat digestion.
- Gorilla teeth contain flat molars for grinding fibrous plants and incisors for stripping vegetation.
Why Don’t Gorillas Eat More Meat?
Gorillas lack adaptations for finding, hunting, and digesting meat seen in true omnivores like bears or carnivores like big cats. Their diet and behaviors reflect their herbivorous nature shaped by millions of years of evolutionary pressures.
Firstly, gorillas do not possess the speed, natural weapons, or predatory instincts required to hunt large prey. Even if they could kill an animal, wild gorillas would lack the required intestinal adaptations to fully breakdown and assimilate meat, fat, and proteins. Their microbiome is calibrated for fermenting the complex carbohydrates found in abundant vegetation.
Switching to a protein-heavy carnivorous diet would upset the delicate balance of microorganisms gorillas rely on to digest plants and derive needed nutrients. Bacteria suited for digesting meat may overgrow in the gorilla gut causing illness. Dangerous food poisoning is a high risk as well from eating decaying flesh raw absent proper antimicrobial acid levels. Carrion quickly accumulates pathogens lethal to those lacking carnivore immune and digestive protections.
The high calorie but sparse meat resources in gorilla habitats acts as selective pressure favoring efficient herbivory. The year-round availability of lower calorie foliage offers a more reliable food source than scattered hunting opportunities. Plants can be consumed easily and continuously without high energy costs of pursuing and killing elusive prey. Evolution shaped the optimal gorilla design for exploiting ubiquitous vegetation, not chasing meat.
Key Takeaways:
- Gorillas lack adaptations for hunting prey including speed, natural weapons, and predatory instincts.
- Gorilla microbiome and intestinal design is specialized for digesting fibrous plants, not meat.
- Reliable vegetation in gorilla habitats provides selective pressure favoring herbivorous traits.
Examples of Gorilla Meat Eating
While not normal, there are some examples of captive gorillas ingesting animal protein under human care. Zoo gorillas are sometimes fed eggs, yogurt, cheese and other high-protein dairy products. These animal foods are offered as occasional treats and enrichment. Quantities must be restricted to limit digestive upset.
There are a few cases of zoo gorillas opportunistically eating meat. In 1986, a zoo gorilla was documented stealing and eating a roasted chicken thrown into its enclosure. Another captive gorilla learned to fish for hatchery trout using a stick, eating several dozen fish whole. While intriguing, these isolated events show curiosity and opportunism, not a deliberate nutritional desire for meat.
Wild gorillas starve themselves when preferred foods are unavailable, rather than expanding into less desirable nutritional options. Their picky eating suggests meat is not purposefully sought after to fulfill some nutritional requirement even in tough conditions. Protein cravings due to an imbalanced diet in human care may drive interest more than instinct. Gorillas seem physiologically and evolutionarily adapted to get all needed nutrients from an herbivorous diet when possible.
Key Takeaways:
- Captive gorillas sometimes receive small amounts of dairy products to enrich their standard vegetable diet.
- Isolated cases show zoo gorillas opportunistically eating meat and fish when available.
- Picky eating habits suggest gorillas are not naturally motivated to eat meat or expand their diets.
Risks of Feeding Gorillas Meat
While gorillas may sample meat and dairy given the opportunity, offering animal products routinely could be hazardous. Sudden shifts away from an herbivorous diet carries significant digestive risks for gorillas.
Meat and other high-protein foods can disrupt the sensitive balance of microorganisms gorillas need to digest plants and absorb nutrients. Just like humans, abrupt diet changes in gorillas may cause gastrointestinal issues like intestinal cramping, diarrhea, and vomiting. High protein diets also make gorilla urine more acidic which can possibly lead to painful kidney stones over time.
There are also disease risks from eating meat. Raw or spoiled flesh may expose gorillas to harmful bacteria, parasites, or dangerous viruses absent in vegetation. Cooked meat reduces this risk but cooking denatures proteins making digestion even more difficult. Cross-contamination of raw meat from processing and storage often occurs as well, even in human kitchens. Overall the risks seem to outweigh any minor benefits of offering gorillas animal-based proteins as anything beyond an occasional treat.
Key Takeaways:
- sudden increases in meat or dairy may disrupt healthy gorilla gut bacteria adapted to digesting fiber
- high protein diets can cause gastrointestinal issues like diarrhea and vomiting in gorillas
- raw or spoiled meat elevates the risk of transmitting harmful pathogens compared to vegetation
Conclusion
In conclusion, gorillas do not normally eat meat. Their physiology and natural behaviors reflect a true herbivore specifically adapted for a fibrous, plant-based diet. Wild gorillas may opportunistically sample insects for extra protein and very rarely taste meat or fish in exceptional situations. However, deliberate meat eating goes strongly against gorilla digestive anatomy, physiology, and evolutionary origins.
While gorillas can ingest small amounts of meat, dairy, and eggs in captivity without apparent harm, it poses a risky deviation from their natural diet. Any nutritional benefits appear minimal and possibly offset by disruptions to their microbiome and gut health. When possible, gorillas are best maintained on a wholly herbivorous diet to mimic their preferred natural feeding habits and physiology.
References
- Popovich, D. G., Jenkins, D. J., Kendall, C. W., Dierenfeld, E. S., Carroll, R. W., Tariq, N., & Vidgen, E. (1997). The western lowland gorilla diet has implications for the health of humans and other hominoids. The Journal of nutrition, 127(10), 2000-2005.
- McGrew, W. C. (2014). Is meat eating by apes an evolutionary step up from herbivory?. Meat eating and human evolution, 179-194.
- Milton, K. (1999). A hypothesis to explain the role of meat-eating in human evolution. Evolutionary anthropology: Issues, news, and reviews: Issues, news, and reviews, 8(1), 11-21.
- Rogers, M. E., Abernethy, K., Bermejo, M., Cipolletta, C., Doran, D., McFarland, K., … & Tutin, C. E. (2004). Western gorilla diet: a synthesis from six sites. American Journal of Primatology: Official Journal of the American Society of Primatologists, 64(2), 173-192.
- Schaller, G. B. (1963). The mountain gorilla: Ecology and behavior. University of Chicago Press.
- Klailova, M., Hodgkinson, C., & Lee, P. C. (2010). Behavioral responses of one western lowland gorilla (Gorilla gorilla gorilla) group at Bai Hokou, Central African Republic, to tourists, researchers and trackers. American journal of primatology, 72(10), 897-906.
- McGrew, W. C. (1974). Tool use by wild chimpanzees in feeding upon driver ants. Journal of Human Evolution, 3(5), 501-508.
- Popovich, D. G., Jenkins, D. J., Kendall, C. W., Dierenfeld, E. S., Carroll, R. W., Tariq, N., & Vidgen, E. (1997). The western lowland gorilla diet has implications for the health of humans and other hominoids. The Journal of nutrition, 127(10), 2000-2005.