The hippopotamus (Hippopotamus amphibius) is one of the world’s largest land mammals, a massive African creature that spends the majority of its day submerged in water. Despite its semi-aquatic lifestyle, the hippo is classified as a megaherbivore, relying on plant matter for its sustenance. Its immense size might suggest a wide-ranging diet, but the feeding habits of this animal are remarkably focused and specialized.
The Primary Food Source
The diet of the common hippopotamus consists almost entirely of short, low-lying terrestrial grasses found along the banks of the rivers and lakes it inhabits. An adult hippo will graze on these grasses for several hours each night, consuming between 35 and 50 kilograms (80 to 110 pounds) of grass in a single night.
This quantity represents only about 1 to 1.5% of its total body weight daily, which is a relatively small intake compared to other large grazing mammals. The hippo’s sedentary, water-based existence allows it to conserve energy, meaning it requires less food proportionately than comparably sized land animals.
The animal’s specialized wide lips, which can measure up to 50 centimeters across in males, are the primary tool used for feeding. These tough, horny lips act like a scythe, grasping and cropping the short grasses close to the ground.
The hippo does not use its large, sharp incisors and canines for grazing, as these teeth are primarily weapons used for defense and combat. Once the vegetation is pulled up, it is passed to the rear molars, which grind the fibrous plant material. The hippo’s digestive system is adapted for this high-fiber diet, using a multi-chambered stomach to facilitate fermentation.
Nocturnal Grazing Habits
The hippo’s feeding activity is strictly behavioral, dictated by the need to protect its sensitive skin from the intense African sun. They spend the daylight hours resting, submerged in water or mud to keep cool and hydrated, only emerging to feed after sunset. This crepuscular and nocturnal routine minimizes exposure to the heat of the day.
Once dusk settles, the hippos leave the security of the water, often moving along well-worn paths to reach their preferred grazing lawns. A typical grazing session lasts for an average of five to six hours, during which they can travel a surprising distance to find the best food sources.
While some individuals may only venture a few kilometers, they are capable of traveling up to 10 kilometers (6 miles) inland in a single night if resources near the water are depleted. The hippos are usually solitary while grazing on land, a stark contrast to their tightly packed social groups in the water during the day.
They return to the water source before dawn to begin the cycle of daytime rest. This nightly journey shapes the entire ecosystem, as their constant trampling and grazing often create distinct, short-grass areas known as hippo lawns.
Addressing Dietary Exceptions
While the hippo is overwhelmingly a herbivore, feeding on terrestrial grasses, there are occasional documented instances of them consuming other items. They may opportunistically eat aquatic plants or fallen wild fruits, though these items constitute a minimal part of their diet.
More notably, researchers have documented rare instances of hippos scavenging on animal carcasses, sometimes even consuming the remains of other hippos. This carnivorous behavior is highly unusual and is not a regular part of the hippo’s feeding strategy. It is often attributed to extreme circumstances, such as severe nutritional deficiencies or periods of drought when their primary food source is scarce.
The hippo’s digestive anatomy is specifically adapted for fermenting plant material, meaning meat consumption is not ideal for their system and can potentially cause digestive issues. These exceptions highlight the animal’s adaptability in times of stress, but they do not change its fundamental biological classification as a grazing herbivore.