The hippopotamus (Hippopotamus amphibius) is one of the largest land mammals in Africa, spending its days in a semi-aquatic existence and emerging at night to feed. The sheer size of this animal necessitates a substantial food intake to maintain its massive body weight. Despite its common presence in rivers and lakes, the hippo’s diet is overwhelmingly terrestrial.
Primary Food Source
The diet of the common hippopotamus is composed almost entirely of grass, making it a dedicated grazer. Hippos prefer short, tender, green grasses found along riverbanks and in the surrounding savanna. They seek out low-lying, short-bladed species that are easily accessible.
Despite spending a majority of their time submerged, aquatic vegetation forms a surprisingly small fraction of their overall food intake. Their digestive system is specifically adapted to efficiently process large volumes of fibrous terrestrial grasses.
How Hippos Graze
Hippos are primarily nocturnal feeders, leaving the water at dusk and returning before dawn to avoid the heat and protect their sensitive skin. A single adult hippo can travel several kilometers, often up to 8 kilometers (5 miles) from its water source, to find suitable grazing patches. They follow established paths, which they maintain and deepen over time, leading them to their preferred feeding areas.
The animal’s unique anatomy dictates how it consumes its food, using its tough, broad lips to pluck or shear the grass close to the root. Hippos do not use their sharp incisors or massive tusks for eating, reserving those teeth for defense and display. An adult hippo consumes an average of 40 kilograms (88 pounds) of grass in a single night of grazing, amounting to only about 1 to 1.5% of its total body weight daily.
Supplementary and Opportunistic Foods
While grass forms the foundation of the hippo’s diet, they occasionally supplement this with other plant materials, particularly during the dry season when preferred grasses are scarce. Supplements include reeds, shoots, and fallen wild fruits, though they do not replace the bulk consumption of grass.
In rare and documented instances, common hippos have been observed engaging in opportunistic carnivory, consuming meat or carrion. Observations include feeding on the carcasses of wildebeest, zebra, and even other hippos. This unusual behavior is not a dietary preference, as their digestive system is poorly suited for processing meat. Scientists hypothesize that these rare acts of scavenging are driven by severe nutritional stress or mineral deficiencies, especially during drought conditions.
The Pygmy Hippo Diet
The pygmy hippopotamus (Choeropsis liberiensis) is a much smaller and more reclusive species. Unlike the common hippo, the pygmy hippo is a browser, preferring to eat a variety of non-grass plants found on the forest floor. They inhabit the dense forests and swamps of West Africa, where short grasses are not a prevalent food source.
Their diet consists mainly of ferns, broad-leaved plants, herbaceous shoots, roots, and tubers. Fallen fruit also makes up a significant part of their foraging, providing a higher quality of nutrition than the fibrous grass consumed by the common hippo. Pygmy hippos spend approximately six hours foraging each night, relying on their solitary nature to find food among the dense undergrowth.