At AllThingsNature, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What Is a Hippopotamus?

Jennifer Long
Jennifer Long

There are two species of hippos, semi-aquatic mammals of the Hippopotamide family. Its Greek name, Hippopotamus amphibious, means river horse. Hippos are tied with the rhinoceros for the spot as the third-largest living land mammal.

A river, or common, hippopotamus is native to the sub-Saharan section of Africa. They remain in nearby lakes and rivers during day hours and graze on land during the evening hours when it is cooler. One hippo can eat 100 pounds (45.36 kg) of food in one day.

Close-up of hippopotamus head and eye.
Close-up of hippopotamus head and eye.

The common hippopotamus species tends to remain in large groups of 15 or more. Females are in greater number than males. A female can weigh about one and a half tons (1360.78 kg), while males can weigh an average of three tons (2721.55 kg). They have thin gray skin that closely resembles elephant skin. It secretes a pink oil substance to protect the hippo from sunburn and keep the skin from drying out.

Hippos are considered the third-largest living land mammal.
Hippos are considered the third-largest living land mammal.

A pygmy hippopotamus is smaller than the common species. It will only weigh about one quarter of the weight and half the height of the larger species. Their skin is similarly thin but is more brown or black in color. The pigmy hippo differs from the river hippo by its thinner bones and sloping spine. Although the pigmy species is also semi-aquatic, their habitat differs because they prefer the swampy forest regions of western African.

Hippopotamuses, regardless of the species, reproduce and give birth in the water. Calves are born after an eight month gestation period, and also nurse underwater. Females in the herd share babysitting and protection duties.

Male, and sometime female, hippos are aggressive and territorial. Although the hippopotamus will anger easily in the water with the herd, grazing is often done alone. While on land, the hippo does not act so aggressively.

Both male and female hippos are aggressive and territorial.
Both male and female hippos are aggressive and territorial.

A hippo will open its mouth very wide to expose its large teeth. Researchers believe this is an intimidation tactic the hippopotamus does try to scare off rivals or predators. Once engaged in a battle, the hippos ram into each other with their mouths wide open. They throw water with their lower jaws and head butt each other as well.

General populations of both species of the hippopotamus are in danger. The pigmy species has a significantly lower population count, but both are suffering. These animals are being hunted for their meat and their ivory teeth.

Frequently Asked Questions

What is a hippopotamus?

The common hippopotamus is native to the sub-Saharan section of Africa.
The common hippopotamus is native to the sub-Saharan section of Africa.

A hippopotamus, or hippo, is a large, mostly herbivorous mammal native to sub-Saharan Africa. It's recognized by its barrel-shaped torso, enormous mouth and teeth, nearly hairless body, stubby legs, and tremendous size. Hippos are the third-largest living land mammals, after elephants and white rhinos, and spend much of their time in rivers and lakes to keep their massive bodies cool under the hot African sun.

How do hippos adapt to their aquatic environment?

Hippos are well-adapted to their aquatic habitats with several unique features. Their eyes, ears, and nostrils are located high on their heads, allowing them to see and breathe while mostly submerged. Their dense bodies, which make them less buoyant, enable them to walk or run along the riverbed. Additionally, a clear membrane covers and protects their eyes while underwater.

What do hippos eat and how much?

Hippos are primarily herbivores, grazing on grasses as their main source of food. They can consume up to 35 kilograms (about 80 pounds) of grass in a single night, according to the African Wildlife Foundation. Despite their large size, hippos eat relatively little for their weight because they lead sedentary lives, conserving energy by lounging in the water during the day.

Are hippos social animals?

Yes, hippos are social creatures and tend to live in groups called pods, bloats, or schools, which typically consist of 10 to 30 individuals, but can swell to hundreds depending on the habitat. These groups are usually dominated by one large male, with the rest being females, their young, and a few subordinate males.

How do hippos communicate with each other?

Hippos communicate through a series of grunts, wheezes, and deep bellows. One of the most distinctive sounds they make is a loud, laughing-like call that can be heard over long distances. This vocalization plays a crucial role in maintaining the social structure within groups and can also signal distress or warn off intruders.

What are the main threats to hippopotamus populations?

The primary threats to hippopotamus populations are habitat loss and illegal hunting. Their natural habitats are being reduced due to agricultural expansion and human settlement. Poaching for their ivory canines, meat, and hide is also a significant threat. The International Union for Conservation of Nature (IUCN) has classified the common hippo as vulnerable due to these pressures.

Discussion Comments


@bear78-- Why are hippos shown so friendly and cute in toys and storybooks?

I too had a hippo toy when I was young. It was purple and very adorable. When I first saw a picture of a real hippo in school, I was very surprised. These animals are very large and not so cute in real life. I would definitely be intimidated if I was around one.

But I guess the trend of making cute toys for not so cute or friendly animals has been around for a while. Like Barnie the dinosaur and Pooh the bear!


@bear78-- That's a great point. People often talk about how aggressive hippootamuses are and how many people they attack and kill annually. But few people talk about how people attack these animals, and hunt them for their meat and teeth. It's very natural for them to be aggressive in these circumstances. They are just trying to protect themselves and their young.


I had several hippo toys as a child and I always loved saying their name. Hippos are one of my favorite animals and I've always found the toys adorable. I must admit though, in the pics where they've opened their mouths, they look very frightening. I'm sad that they are under the risk of being endangered though. The fact that they are being hunted explains why they are aggressive. People just need to leave them alone.

Post your comments
Forgot password?
    • Close-up of hippopotamus head and eye.
      By: photo 5000
      Close-up of hippopotamus head and eye.
    • Hippos are considered the third-largest living land mammal.
      By: sattapapan tratong
      Hippos are considered the third-largest living land mammal.
    • Both male and female hippos are aggressive and territorial.
      By: Uryadnikov Sergey
      Both male and female hippos are aggressive and territorial.
    • The common hippopotamus is native to the sub-Saharan section of Africa.
      By: Ruslan Olinchuk
      The common hippopotamus is native to the sub-Saharan section of Africa.