Right / left / up / down arrows They are massive aquatic animals with a barrel-shaped body. The common hippopotamus is much larger as it measures 1.50 m at the withers, females are 3 to 4 m long and weigh 1 to 2 tons, and males are 4-5 m in length and weigh 2.5 to 3.5 tons (up to 4.5 tons for the biggest), while the dwarf hippopotamus measures only one meter at the withers for 1.50 to 1.75 m in length and a weight From 170 to 275 kg. Their legs form pillars. The legs of the dwarf hippopotamus are more detached and clearly more suitable for walking - the four fingers are free, not connected by a membrane, and the nails are pointed. This allows it to adhere well to the soil, even if it is uneven, in its habitat consisting of marigots and damp undergrowth. They have a massive head with a wide mouth that can open up to 180 degrees, with impressive tusks that can measure more than 60 cm in amphibious male hippos. Their eyes, ears and nostrils are placed at the top of the head. Their nostrils may close by contraction when they dive, which proves very practical in their amphibious lifestyle since they can thus avoid the entry of water into their lungs. In the same way, their auditory ducts become clogged when they move under water. The two species differ in particular from the shape of the ears, the arch ridges are much more pronounced in the amphibious hippopotamus.
The observed behaviors differed in both species. The common or amphibious hippopotamus lives in large groups dominated by a polygamous and irascible male, while the dwarf hippos live in pairs or very small groups. The amphibious hippopotamuses spend the day in the water to protect themselves from the sun, while the dwarf hippos spend the day hidden in the forest, in the marshes or even in burrows. Some hippos are accompanied by birds that come to eat their ticks, but so they also remove some flesh. Some hippos may remain marked. Although they are herbivorous, they are among the most dangerous animals in Africa. They fiercely protect their territory, causing most of the attacks on humans - they make about 300 deadly victims a year. This is the main reason for the fact that they have never been domesticated by man.