by Wildlife South Africa

Latin Name: Hippopotamus Amphibius
Afrikaans: Seekoei
Distribution in South Africa
Hippotamus, plural Hippopotami or commonly named Hippos in South Africa are found mainly in protected areas, private game reserves and the Kruger National Park. They also occur outside of these areas especially in rivers in the northwestern, northern, northeastern as well as in the eastern parts (northern KwaZulu-Natal). 
Hippos need permanent open water like rivers, dams, or pools in rivers where they can submerge, with sandbanks where they can bask in the sun for periods of time. They also need enough grazing grass in the area.
Hippos are semi–aquatic and gregarious animals. They gather or form pods schools of up to 30 animals or more depending on the water level and time of season. Hippo pods consist mainly of cows and young hippos with a matriarch and a dominant (territorial) bull in control of the territory. Single bulls are also often found. Cows with very young calves often stay on their own for a few months before rejoining the pod.
Day or night
Hippos spend their days resting mainly in the water although in winter and on cool days might be resting on sandbanks and basking in the sun especially in winter months. They feed mainly at night.
Difference between male and female
Male (bull) and female (cow):
Bulls are larger than cows
Male: up to 2000 kg. (Average 1500 kg) 
Female: up to 1700 kg. (Average 1300 kg)
After mating which takes place mainly in the water (seldom on land), a single calf is born any time of the year mostly in a quiet place in the thick reeds next to the river and sometimes in shallow water. Calves also suckle on land and under water however they come up often to breathe.
Gestation period
7 to 8 months
Up to about 40 years
Diet / Food and water
Hippos are grazers of selected grass species as well as young shoots of reeds. Although they usually feed nearby or only a few kilometers away from water at night, in exceptional cases they can travel up to 30 kilometers away from water to feed before returning. The distance they will travel depend on the availability of food.
Lion, Crocodile (only a danger to young Hippos), Humans, loss of habitat.
Do not often occur outside National Parks, game reserves or protected areas. As river systems become more populated by humans, the numbers of Hippos decrease.
Interesting facts
Hippos can be very aggressive, especially territorial bulls and cows with calves.
The hippo’s extremely loud and noisy grunts, bellows, blows rumbling snorts, loud grunts and raucous cries; blowing noises when coming up for air, snorts and roars – can be quite disturbing to newcomers to the bush, however it is typical of the African bush near river systems.
An adult Hippo bull can eat up to 130 kg of grass per day.
Hippos have large canines that can inflict serious wounds – the bottom teeth are by far the largest - Bulls especially have very large lower canines up to nearly one and a half meters.
An adult Hippo can stay underwater for up to 6 minutes and more before coming up to breathe.
Hippos actually walk underneath the water on the bottom of the dam or riverbed.
In areas of cultivations and crop farming with vegetables, mealies, sugarcane, bananas and paw paws, hippos can destroy large chunks of the crop and are sometimes shot by farmers.
They can run at speed of about 30 kilometers per hour.
When hippos fight, bulls defending their territories, it can lead to serious injury and often death. It is said to be some of the most vicious fights in the animal world.
It is often said that of all animals, hippos are the greatest killers of humans in Africa, however while humans remains are always found after a hippo attack, Crocodiles never or hardly ever leave any remains behind when they kill humans. It would therefore be very difficult to ascertain which of crocodiles or hippos kill the most humans. In the rural areas when people go missing, the villagers attribute this to various reasons while in fact it may be largely due to crocodile attacks.
Camp fires at night often receive hostile attention from especially territorial bulls, which might come to investigate and perhaps even trample on the fire.