Gorillas are among the largest great apes, known for their complex social structures and overwhelmingly herbivorous diet. Their feeding habits often lead to questions about less common behaviors, such as the consumption of their own fecal matter, a practice known as coprophagia. Understanding this behavior requires looking at the biological and environmental pressures influencing a gorilla’s nutritional strategy.
Does This Behavior Occur in Gorillas?
Yes, gorillas have been observed engaging in coprophagia, though it is not a routine part of their daily life in the wild. Observational evidence suggests the behavior is rare in free-ranging populations, typically occurring incidentally as they forage. Wild western gorillas, for example, have been noted to re-ingest undigested, nutrient-rich seeds, such as those from the Dialium species, found in their feces.
The practice is seen more frequently in captive settings, highlighting the influence of environment and diet. In zoo environments, coprophagia may be linked to factors like boredom or a diet lacking the volume and fiber of their natural forage. When a captive gorilla’s diet is adjusted to more closely resemble high-fiber, lower-density wild forage, a reduction in the incidence of coprophagia has been documented.
Nutritional Purpose of Recycled Waste
When coprophagia occurs, it primarily serves a physiological purpose, allowing the animal a second chance to extract nutrients not fully absorbed during the initial digestive pass. The gorilla digestive system is adapted for processing large volumes of plant matter but is not perfectly efficient, especially with tough fibers. Fecal matter contains partially broken-down plant material, which yields additional energy upon re-ingestion.
This practice is a form of nutrient recycling common among herbivores whose digestive processes break down food late in the gut. A primary benefit is the recovery of B vitamins, which are synthesized by gut bacteria in the lower intestinal tract. By consuming their own feces, gorillas access these vitamins, especially Vitamin B12, which would otherwise be lost. Ingestion of feces also helps maintain a healthy balance of gut microbiota, which are essential for proper digestion.
The Standard Gorilla Diet
The feeding behavior discussed above contrasts sharply with the gorilla’s primary, day-to-day diet. Gorillas are predominantly herbivores, sustaining their massive body size almost entirely on plant life. Their diet is characterized by high volume and fibrous content, requiring them to spend nearly half their waking hours foraging and eating.
An adult male mountain gorilla, for instance, may consume up to 34 kilograms (75 pounds) of vegetation daily to meet caloric demands. The bulk of this intake consists of leaves, stems, pith, and shoots. Mountain gorillas rely heavily on foliage due to their high-altitude habitat, while lowland gorillas consume a more diverse diet that often includes a greater proportion of seasonal fruits.
Their digestive tracts are designed to process this large quantity of low-quality forage, which is why their intestines are proportionally longer than those of humans. The sheer volume of plant matter they consume provides sufficient moisture, meaning wild gorillas rarely need to seek out water sources for drinking.