They can weigh as much as three and a half tons and their ‘hide’ (skin) can weigh up to half a ton alone. It can measure up to 13 feet long (twice as long as a very tall human being) and 5 feet tall.
Believe it or not, these large, docile looking animals are actually very aggressive. Despite their size, hippos can out-run a human and can reach speeds of 30 miles per hour.
Hippos have developed some well known rituals to show aggression – the large ‘yawn’ does not mean hippo is tired, it is one of their most aggressive forms and shows confrontation in the water. Basically, being unpredictable, anything that gets in their way will be bitten or trampled.
They are amazingly agile animals and good climbers for their size. At night they will climb steep banks to graze on grass. They can get through around 100 pounds of grass in one night. This grazing goes on for most of the night, then, before sunrise, they head back into the waters and swamps to digest their food and for another day of lazing beneath the waters surface.
Male hippos are about 7 years old and females about 9 years old when they become ready to mate. Hippo mating usually happens within the dry seasons when most of the hippos have congregated around water sources. Mating usually takes place under the water.
The female hippo will carry her baby for about 240 days. When the time comes to give birth, she will separate from the herd and isolate herself.