The hippopotamus is one of Africa’s largest and most recognizable mammals, spending its days submerged in water across various habitats. It is primarily known for its herbivorous diet and aggressive territorial nature. While the common hippo is overwhelmingly a plant-eater, rare instances of meat consumption have been scientifically documented, which sometimes includes feeding on the remains of its own species.
The Hippo’s Primary Diet
The hippopotamus is classified as a megaherbivore, meaning its diet is composed almost entirely of plant matter. Specifically, their diet consists of short grasses, which they crop using their specialized, wide lips. Hippos prefer grasses found close to water sources, and they only rarely consume aquatic plants.
Their feeding routine is nocturnal, as they leave the water at dusk to graze on land for approximately five to six hours. During this nightly foraging, an adult hippo typically consumes between 80 to 110 pounds (40–50 kg) of grass. Their digestive system is adapted for this high-fiber diet, featuring a three-chambered stomach that functions as a foregut fermenter. This process allows microbes to break down the tough cellulose in the grass, ensuring they extract maximum nutrients.
Documented Instances of Meat Consumption
Despite being overwhelmingly herbivorous, hippos have occasionally been observed engaging in carnivorous behavior, though this is not a regular part of their diet. These instances usually involve scavenging on carrion (necrophagy). Hippos have been documented feeding on the carcasses of various animals, including impalas, wildebeest, and zebras.
Scientific theories suggest this deviation from their standard diet is often linked to environmental pressures like droughts, causing nutritional stress or protein deficiencies. In times of scarcity, meat can serve as an alternative source of energy and protein. Some researchers propose that meat-eating may be underreported, as hippos graze at night when human observation is difficult. The hippo’s digestive tract is not optimized for carnivory, but it does not prevent meat consumption.
The hippo’s size and aggressive, territorial nature may facilitate opportunistic meat consumption. Their powerful jaws, while primarily used for defense and display, can process meat. Instances of hippos killing and partially consuming other animals have been reported, although scavenging remains the more common form of this rare behavior.
Cannibalism in Hippos
True cannibalism—the consumption of a member of the same species—is a rare, but documented, phenomenon in hippos. The behavior is almost exclusively necrophagy, meaning the hippo feeds on the remains of an already deceased conspecific. Documented cases include hippos feeding on the carcasses of other adults and, in some instances, deceased young.
While many incidents of meat-eating are attributed to nutrient desperation during dry seasons, hippo cannibalism has also been observed during periods of adequate rainfall. This suggests that opportunism or other unknown factors may be involved alongside nutritional need. Consuming a decaying body, especially one from their own species, carries a significant biological risk.
This risk is particularly notable in the context of disease transmission, such as anthrax. When anthrax outbreaks occur, hippos that scavenge on the infected carcasses of other hippos can contract the bacteria, leading to further spread and mortality within the population. While the behavior provides a short-term nutrient gain, it can have severe consequences for herd health. Cannibalism is an anomalous, survival-driven action rather than a standard dietary component.