Hippopotamuses are large, semi-aquatic mammals primarily found in sub-Saharan Africa. They inhabit rivers, lakes, and swamps, spending much of their day submerged to stay cool and protect their sensitive skin from the sun. Despite their aquatic lifestyle, these creatures are herbivores. This article explores the feeding habits of hippos.
Primarily Grass Eaters
Hippos are predominantly grazers, with terrestrial grasses forming the vast majority of their diet. They primarily consume short, green grasses, which they crop with their powerful lips. An adult hippo can consume approximately 40 to 50 kilograms (88 to 110 pounds) of grass in a single night. This intake sustains their large body mass, which can range from 1,500 to 3,200 kilograms for males and around 1,300 to 2,240 kilograms for females.
Their digestive system is adapted for a diet rich in fibrous plant material, featuring a complex three-chambered stomach. This allows them to efficiently process the nutrients from the grasses they consume.
How Hippos Graze
Hippos are primarily nocturnal feeders, emerging from the water at dusk to graze on land. This behavior protects their skin from the intense African sun, as they lack sweat glands and are susceptible to sunburn. They travel 3 to 8 kilometers (1.9 to 5 miles) from their water bodies to preferred grazing areas.
Their method of grazing involves using their broad, horny lips to grasp and tear grass. Unlike many other herbivores, their large canines and incisors are primarily used for combat and defense, not for chewing food. Once torn, the grass is passed to their molars, which have complex enamel folds designed for grinding. This unique feeding adaptation allows them to efficiently harvest large quantities of short grasses.
Variations in Their Diet
While grasses are the primary food source for hippos, their diet can occasionally include other plant materials. If terrestrial grasses are scarce, such as during dry seasons, hippos may consume some aquatic vegetation, including reeds, shoots, and fruits. Aquatic plants make up a minimal portion of their overall diet despite their semi-aquatic nature.
In rare instances, hippos have been observed consuming carrion. This behavior is anomalous and not a typical part of their diet, often occurring during periods of nutritional stress or food scarcity. Their digestive system is not designed for processing meat, and such instances are attributed to unusual circumstances rather than a shift towards omnivory.
Hippo calves initially rely on their mother’s milk for nourishment. They begin to experiment with eating grass at around three weeks of age, though they continue to nurse for approximately a year. Serious grazing on grass starts around five months of age, as their digestive system develops to handle solid plant matter. The transition to a solid diet is gradual, ensuring their developing digestive system can adapt to fibrous foods.