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River horses are one of Africa’s most magnificent sights. Except they’re not horses, they are hippos.

They are funny fellows however you call them. Barreling around like prehistoric giants, river horses don’t always live in rivers and they are not very good at show jumping.

However, these surprising giants are one of the world’s most evolved creatures. They weigh 1800 kg despite living off grass. And they can run faster than you!

But why river horse? What’s with the silly name? Read on, as we debunk river horse and other popular hippo myths.

Why is a Hippo Called a River Horse?

Hippo pod in the Luangwa river, South Luangwa

Let’s look at some local names.

In Zulu, the hippo goes by the name imvubu.

Go on a safari in East Africa and you can use their Swahili name – kiboko.

Hippopotamuses get their common name from the ancient Greeks. And guess what? Hippopotamus literally translates into English as river horse.

It’s unsurprising that the Greeks came up with such a name. Historians named hippos based on drawings, so an African animal received a European name from people who had never been to Africa!

Hippos came before horses as well. Fossil remains show that an early hippo called a Kenyapotamus (really, who comes up with these names?!), lived in Africa 16 million years ago. Hippos have been around for 8 million years, whereas the equus species (horses) for just 5 million years.

Instead of river horse, why not a lake pig? Or a sea cow? It sounds bizarre, but the Afrikaans word for hippo is seekoei, which literally means sea cow!

Similarities Between Horses and River Horses

Hippo with grass mouthful, Botswana

So a hippo is not a horse but surely the Greeks based on their theory on some similarities.

They’re both mammals. They are both herbivores living off a predominantly grass-based diet. And they can both run.

Don’t believe us? A hippo can run at 30 km/h and will charge over anything that gets in its way. Never stand between a hippo and the water because you will be trampled. If a hippo does run for you, the best way of escape is to run uphill.

When they advance they look like running horses in slow motion. Or perhaps weird astronauts on the moon. 🙂

Horses catch a lot of sleep while standing up, just like giraffe. River horses don’t need to lie down to sleep either. Instead they sleep underwater! How incredible is that!

Hippos can hold their breath for over five minutes. When in sleeping mode they drift off underwater and surface automatically for a breath of fresh air, all without opening their eyes or waking up.

Want more similarities? Hippos and horses can both live to around 40 years of age and have long gestation periods of 8 and 11 months respectively.

Differences Between River Horses and Horses

Horse vs river horse

The differences stare us all in the face. A horse looks like a horse. And a river horse looks like a hippo! How did the Greeks get so confused about this?

One remarkable difference is the fact that river horses cannot actually swim. They are simply too heavy to swim. Just imagine those squat legs and round feet propelling 1800 kg of body mass through the water.

But why swim when you can hold your breath for five minutes? River horses sink to the bottom of the water and walk on the river bed.

It’s fascinating how they can choose to float or sink so effortlessly. It’s incredible, especially when you consider how much they weigh and how inefficient their bodies appear to be.

Another key difference is their farting abilities. Horses can let off some snortingly loud and smelly farts. In comparison, hippo farts are virtually silent. A single YouTube video suggests hippo have the loudest farts of them all, but it’s just a kid adding sound effects to some footage from a zoo.

Hippos do not fart from their mouths either.

The biggest difference between river horses and everyday horses is where they live. Not just that hippos only live in Africa, but that most hippos are wild animals, whereas most horses are captive and selectively bred.

If River Horses Are Not Horses, What Are They Close To?

Hippo head close-up, underwater

It was only 100 years ago that naturalists believed hippos to be most closely related to pigs. This is the obvious guess, especially for anyone who has witnessed a West African pygmy hippo.

Hippos and pygmy hippos are the only two living species in the Hippopotamidae genus. And they share a common ancestor with a rather unexpected animal – the whale.

Yep, it’s strange but true that hippos and whales have the same ancestor. 60 million years ago they were the same thing, a semi-aquatic giant that lived on land and water, known colloquially as a walking whale.

Whales and hippos share some incredibly unique characteristics, and they certainly have more in common than river horses and horses.

They are both mammals that can suckle milk underwater. They give birth in water. River hoses and whales have the same multi-chambered stomaches and an innate ability to communicate when under water.

Think about their bodies as well. Put a hippo in the water and it looks more like a whale than a horse. They both have a thick fatty layer to keep them safe and cool.

Both species have these magnificent lungs that can expand and instantly take in air. That’s how river horses and whales can spend two seconds on the surface then five minutes (or up to 90+ minutes for whales) submerged on a single breath.

Where to See Hippos in the Wild

Hippo pod in the wild

So perhaps the Greeks did get something right after all. They recognised that these astonishing animals were creatures of the water, not the land, so they prefixed the name with river.

It’s a shame about horse. But ancient Greeks weren’t the only ones to rename things from Africa without even setting foot on the continent.

Still, hippo or river horse, these are magnificent animals to see on an African safari. And the great news is that hippos live all across sub-Saharan Africa. They’re one of the continent’s most common safari sights.

Just look out for rivers, lakes and large bodies of water. Hippos will be grunting and bellowing in the water during the day. Then after dark they come out to graze on surrounding grasslands.

Just remember, hippos, like horses, can be very dangerous animals when they’re not given distance and respect.