Hippopotamus

Hippopotamus at a glance

Need to know

• Hippopotamuses are the third-largest land mammals on Earth, after elephants and rhinoceroses.
• Despite their bulky appearance, common hippos can run up to 30 km/h (19 mph) on land.
• Hippos are highly territorial in water but more solitary on land.
• Pygmy hippos are nocturnal, secretive, and less aquatic than their larger relatives.
• Hippos produce a unique reddish “sweat” that acts as a natural sunscreen and antiseptic.
• Hippos are responsible for more human fatalities in Africa than most other large animals.

About the Hippopotamus

Hippopotamuses are large, semi-aquatic mammals native to Africa. The family Hippopotamidae contains two living species: the imposing and social common hippopotamus (Hippopotamus amphibius), which thrives in rivers and lakes across sub-Saharan Africa, and the much smaller, elusive pygmy hippopotamus (Choeropsis liberiensis), which hides in the forests of West Africa. Both species share a love of waterways but differ vastly in their size, social behavior, and habitat preferences.

Common hippos are famed for their enormous mouths, barrel-shaped bodies, and surprising speed both in water and on land. Despite a seemingly docile appearance, hippos are considered highly dangerous due to their unpredictable temperament and powerful jaws. Pygmy hippos, by contrast, are understated forest dwellers, spending much of their lives alone and becoming active mainly at night. These unique mammals are crucial for maintaining aquatic and riparian ecosystems, but face ongoing threats from habitat loss and hunting.

Physical characteristics

Size: Common hippo: 3.3–5.2 m long; Pygmy hippo: 1.5–1.75 m long. Weight: Common hippo: 1,200–2,000 kg (males up to 4,000 kg); Pygmy hippo: 180–275 kg. Lifespan: Average 40 years, up to 55 years (in captivity/exceptional cases).

• Large, nearly hairless barrel-shaped body
• Large head with wide mouth and massive tusks
• Thick, mostly grayish-pink skin secreting reddish 'blood sweat'
• Small ears and eyes placed high on the head
• Short, stumpy tail

Notable species

• Common Hippopotamus (Hippopotamus amphibius) — Vulnerable. Permanent rivers, lakes, and wetlands in sub-Saharan Africa Regions: East Africa, West Africa, Central Africa, Southern Africa, Nile River Basin, Lakes and rivers of Zambia, Lakes and rivers of Tanzania.
• Pygmy Hippopotamus (Choeropsis liberiensis) — Endangered. Dense forests, swamps, and riverine areas in West Africa Regions: Liberia, Sierra Leone, Guinea, Ivory Coast, West African Upper Guinea forests.

Habitat and range

Original range: Widespread across Africa; the common hippopotamus evolved in sub-Saharan and North African wetlands; pygmy hippo in West African forests.

Current distribution: Common hippo now found throughout sub-Saharan Africa in major river systems; Pygmy hippo restricted to West African forests.

Preferred environments: Permanent rivers, Lakes and wetlands, Floodplains, Swampy forests (pygmy hippo)

Regions: East Africa, Central Africa, South Africa, West Africa, Nile River Basin, Zambezi River, Upper Guinea forests

Where to see Hippopotamus

• Serengeti National Park, Tanzania — June to October (dry season). Look for hippos gathering in large pods in rivers and pools.
• Okavango Delta, Botswana — May to September. Hippos are common in the region's vast wetlands—boat safaris offer the best viewing.
• Niger River, Mali — November to February. View hippos in the inland delta during morning or evening boat rides.
• Sapo National Park, Liberia (Pygmy hippo) — Year-round, but dry season (October to May) for better access. Spotting pygmy hippos is difficult—they are shy and mostly nocturnal, best seen with experienced local trackers.

Behavior and diet

Diet: Mainly grasses and, occasionally, fallen fruit (for common hippo). Pygmy hippos feed on ferns, broad-leaved plants, grasses, and some fruits.

Social structure: Common hippos are highly social, living in groups (pods) of 10 to 30 individuals; pygmy hippos are solitary or found in pairs.

Communication: Hippos communicate through grunts, roars, wheezes, honks, and underwater 'clicks'. They use vocalizations, body postures, and territorial marking.

• Mark territory by spraying dung with their tails.
• Submerge up to their eyes and nostrils to stay cool and breathe.
• Yawn as a threat display to show off their huge canine teeth.
• Can sleep underwater, automatically surfacing to breathe without waking.

Interactions with other animals

• Nile crocodile (competitive): Hippos and crocodiles share river habitats; hippos dominate in the water and can be aggressive toward crocodiles.
• African lions (predator): Lions very rarely attack young or sick hippos, but adults are generally avoided due to their size and aggression.
• Humans (competitive): Hippos clash with people over access to water and crops, leading to frequent conflicts and making hippos one of Africa's most deadly animals for humans.

Conservation

IUCN Red List status: Vulnerable

Threats

• Illegal hunting for meat and ivory (canine teeth)
• Habitat loss from agriculture, settlement, and damming
• Conflict with humans (crop raiding, accidental encounters)
• Water scarcity and river ecosystem changes

Conservation efforts

• Creation of protected reserves and sanctuaries
• Anti-poaching enforcement and community outreach
• International trade regulations for hippo ivory
• Habitat restoration and ecosystem management

How to help

• Support reputable wildlife conservation organizations active in Africa
• Practice responsible tourism and respect hippo habitats
• Raise awareness about the threats facing hippos
• Avoid purchasing hippo ivory or illegal wildlife products

Hippopotamus facts for kids

Hippos are huge animals that live in Africa and love spending time in rivers and lakes. They spend their days in the water to keep cool, and at night they go on land to eat grass. Hippos look friendly but can be very dangerous if they feel threatened.

• Hippos can open their mouths extra wide—almost 180 degrees!
• A baby hippo is called a calf and can weigh as much as an adult human when born.
• Despite their size, hippos can swim and even walk underwater.
• Their skin makes a special pink goo that works like sunscreen!
• Pygmy hippos are much smaller and love to hide in forest streams.

Did you know? Did you know a hippo can hold its breath underwater for up to five minutes, and some can even sleep underwater without waking up?

Watch & learn

• Hippos: Africa's River Giants — BBC Earth. This documentary delves into the fascinating lives of Hippopotamidae, revealing their unique social structure, daily routines, and survival challenges along African rivers. Stunning cinematography and insightful narration provide a comprehensive overview of these massive mammals.
• Unexpected Behavior of Hippos in the Wild — National Geographic Wild. Explore the surprising and sometimes dangerous behavior of hippos in their natural habitat, with dramatic footage and expert commentary that shed light on why these seemingly docile giants are among Africa's most dangerous mammals.
• Hippos: Guardians of the River — Smithsonian Channel. Learn about the ecological role of hippos in river systems and their interactions with other species. This documentary features close-up footage and expert perspectives on Hippopotamidae family dynamics and conservation struggles.
• Nature's Great Gatherings: Hippos of the Mara River — PBS Nature. Follow a family of hippos through the seasons along Kenya's Mara River, observing their complex relationships, parenting rituals, and how they coexist and compete with crocodiles and other river inhabitants.
• Hippo Battles: The Most Dangerous Mammal — BBC Earth. Watch as BBC explores intense territorial fights and dramatic confrontations among hippos, unveiling the power, aggression, and surprising vulnerability of these mammalian giants in the wild.