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Critter Guide
Mammals: Hippopotamus


The Common or River Hippopotamus, long depicted as a slow, gentle creature, will often behave violently when provoked. Extremely agile in the water and rapid runners on land (up to 18mph, or 30kph), hippos breathe air but sleep underwater. Their ears fold over and their nostril flaps close as they submerge. Hippos remain asleep as their bodies automatically resurface and submerge over and over again during the night. "Hippopotamus" comes from a Greek phrase meaning "river horse," but hippos are actually related to dolphins!

Where do they live?:

Hippos feed on the grasslands in and swim in the rivers and lakes of West and East Central Africa. Mainly located in large populations in protected areas, hippos need plenty of water and grazing material. As such, they rarely live in mountains, but can make do if the water temperature is high enough to keep them healthy.

What do they eat?:

A hippo can weigh anywhere from 3,000 to 8,000 lbs., giving them a large appetite. Hippos travel 2 to 6 miles to reach their food. They spend up to five hours a night grazing. During the day, hippos rest, socialize, and digest in the water.

Critter Fact:

Hippos live in large herds led by one dominating male who controls the territory. Occasionally he will allow other males to mate with the numerous females of the herd, but often fights will ensue if an outsider attempts to usurp this male's place. Hippos have long sharp tusks that can do a lot of damage to the tough hides of crocodiles. The calves of the herd avoid crocodiles and other dangers by spending all of their time in together. In fact, adult females have been known to "baby-sit" the young of other mothers!

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Did You Know?

A hippo's skin secretes a pinkish oil -- that early scientists mistook for blood -- that protects it from the elements. This thick pink mucus is thought to soothe a hippo's skin, which takes a beating from years of exposure to the sun and the teeth of other hippos.