After elephants and white rhinos, the hippopotamus is the third largest living mammal on land and their hides alone can weigh up to half a ton. In ancient Egypt, hippos were considered a female deity of pregnancy and they were regarded as sacred animals, but in recent times they were wiped out in this region due to conflicts with humans and their interference with agricultural activities. However, hippos continue to thrive in other parts of Africa.
Hippos are amphibious creatures, evenly agile in water and on land. Their feet have four webbed toes which are splayed out evenly for even weight distribution and therefore adequately support their movement on land and in water. They are quite fast runners on land and although they have short, strong, and stubby legs, they can reach 40kmph, much faster than humans.
They have grey, thick skins with virtually no hair on their bodies. They also don’t have any sweat or sebaceous glands and therefore have to rely on water and mud to keep their cool. They do, however, secrete a viscous red fluid that acts as natural sun protection and may possibly also be a healing agent. Hippos use their flat, paddle-like tails to spread their excrement, which marks their territories and indicates the social status in the herd.
There are two hippo species found in Africa. The large hippo (Hippopotamus Amphibius), found in East Africa, occurs south of the Sahara. This is the most common species and they are social group-living mammals. In some areas, their numbers are so vast that “culling” is used to control populations that have become larger than the habitat can sustain.
The other, much smaller (440 to 605 pounds) species of hippo is the pygmy hippopotamus (Choeropsis Liberiensis). This species is very rare and is limited to restricted areas in West Africa where they are shy, solitary forest dwellers.
Hippos have a flexible social system defined by hierarchy and by food and water conditions. Usually, they are found in mixed groups of about 15 individuals held by a territorial bull, but in periods of drought large numbers are forced to congregate near limited pools of water. This overcrowding disrupts the hierarchical system, resulting in even higher levels of aggression, with the oldest and strongest males most dominant. Old scars and fresh, deep wounds are signs of daily fights that are accompanied by many vocalizations.
A single young is born either on land or in shallow water. In water, the mother helps the newborn to the surface, later teaching it to swim. Newly born hippos are relatively small, weighing from 55 to 120 pounds, and are protected by their mothers, not only from crocodiles and lions but from male hippos that, oddly enough, do not bother them on land but attack them in water.
Young hippos can only stay underwater for about half a minute, but adults can stay submerged for up to six minutes. Young hippos can suckle underwater by taking a deep breath, closing their nostrils and ears, and wrapping their tongue tightly around the teat to suck. This procedure must be instinctive, cause newborns suckle the same way on land. A young hippo begins to eat grass at 3 weeks, but its mother continues to suckle it for about a year. Newborns often climb on their mothers’ backs to rest.