The hippopotamus (Hippopotamus amphibius) is one of Africa’s most easily recognized and imposing megafauna. Weighing up to 5,000 kilograms, this massive mammal is primarily defined by its semi-aquatic existence. Hippos spend the majority of the day submerged in water to protect their sensitive skin from the intense African sun, only emerging under the cover of darkness to feed. The geographic locations where these animals can successfully inhabit are strictly dictated by the availability of both water and nearby grazing land.
The General Sub-Saharan Distribution
The Common Hippopotamus is found exclusively within Sub-Saharan Africa. It was extirpated from its historical range in North Africa, which once extended to the Nile Delta in Egypt. The current distribution spans a vast area, extending from major river systems in West Africa (Senegal and Gambia) eastward toward the Horn of Africa (Ethiopia and Somalia). The range continues south through the continent to parts of South Africa and Swaziland.
Despite this extensive geographical spread, the hippo population is highly concentrated and fragmented. The vast majority (over 77%) of the continent’s approximately 115,000 to 130,000 individuals reside in Eastern Africa. Zambia and Tanzania support the largest numbers, hosting tens of thousands of hippos within their extensive river and lake systems. The species is generally absent from the extreme arid regions, such as the Sahara Desert and the driest parts of the Horn of Africa, as well as areas where they have been locally hunted to extinction.
Essential Aquatic and Terrestrial Habitat Needs
The presence of the Common Hippopotamus depends entirely on the continuous availability of two distinct habitat types. For daytime refuge, they require deep, permanent water sources, such as major rivers, freshwater lakes, and extensive swamps. This water acts as a thermal regulator, preventing their skin from overheating and dehydrating under the tropical sun.
The ideal aquatic habitat is generally still water with gently sloping shores, allowing easy entry and exit, and a preferred depth of about two meters for full submersion. This water environment is also where mating and the birthing of their calves occur.
The second habitat requirement is accessible, short-grass grazing land, often referred to as “hippo lawns,” located close to their daytime water sanctuary. Hippos are strict herbivores and leave the water only after dusk to graze. They typically travel between three and five kilometers from the water’s edge each night to consume up to 40 kilograms of grass. The balance between a secure water refuge and a nearby, rich food supply is the primary ecological factor limiting their distribution.
Range Differences Between Species
Africa is also home to the Pygmy Hippopotamus (Choeropsis liberiensis), a much smaller species with a drastically different and restricted range. The Pygmy Hippo is confined almost entirely to the dense, lowland tropical forests and swamps of West Africa. Its distribution is fragmented across only four countries: primarily Liberia, with smaller, isolated populations in Sierra Leone, Guinea, and Côte d’Ivoire.
Unlike the Common Hippopotamus, which favors open river systems and savanna grasslands, the Pygmy Hippo is a shy, solitary, nocturnal forest dweller. It uses streams and wallows mainly as a hiding place and to keep its skin moist, spending significantly more time foraging on land. This species’ highly specialized habitat requirement of dense forest cover means its range does not overlap with the more widespread Common Hippo.