The Hippopotamus, a semi-aquatic mammal
The common hippopotamus, or Hippopotamus amphibius for short, is a semi-aquatic mammal found in the sub-Saharan region of Africa. It can be distinguished from its counterpart Hexaprotodon liberiensis, commonly known as the dwarf hippopotamus, due to its smaller size.
The common hippopotamus, the more emblematic of the two, is one of the largest land mammals, alongside rhinoceroses and elephants. An adult male can measure between 3 and 5 metres and weigh up to 3,200 kilos. The name Hippopotamus, which translates as “river horse” in Greek, is a reminder of the special lifestyle this mammal has adopted. It spends most of its days lounging passively in the water, only coming ashore at nightfall to feed.
As it is unable to submerge completely, evolution has given the Hippopotamus a special morphology that enables it to keep its sense organs out of the water while the rest of its body is underwater. This particularity also enables it to remain on the alert for the various threats hanging over these wild lands. In addition, it secretes an oily substance that protects the parts of its body exposed to the sun. This reddish-pink protective oil has also contributed greatly to the animal’s popularity.
How does a Hippopotamus behave?
Although popular culture has given it a rather childlike and weary appearance, the Hippopotamus is in reality a ferocious and very territorial animal. This aspect, often forgotten by Westerners, generally leads to a difficult cohabitation between the Hippopotamus and the local people of Africa. Although highly gregarious during the day, the hippopotamus quickly becomes a solitary animal when night falls, making it much harder to keep an eye on, and the agricultural fields pay a high price. In fact, this enormous mammal is often the cause of a great deal of destruction during its nocturnal feeding bouts.
During the day, the animal settles down and forms groups of between 2 and 150 individuals. In society, male hippopotamuses do not try to attract females, or at least not directly. The two individuals are attracted through an intermediary, their territory.
The male, who is very dominant, takes care of finding a comfortable habitat and defending it from various predators. It is this same territory which, depending on its quality, will have an attractive effect on the females of the species.
The female looks after the young, accompanying them to feed at night when the herds separate. However, the young hippos can quickly become a threat to the adult males in the herd during the breeding season, when intra-herd clashes over leadership can occur.
Hippopotamus: an endangered species?
According to scientific studies, hippopotamus populations are declining in more than half the countries where the species occurs. The number of individuals is currently estimated at around 120,000. This sudden disappearance is closely linked to the large-scale poaching of the species. The ivory in its gigantic teeth and the animal’s meat are a rare commodity that fuels both the legal and illegal trade. In addition, the significant development of human activities in areas where the hippopotamus lives has led to an increase in encounters between humans and animals.
What solution is provided?
In response, many African countries have asked for the Hippopotamus to be added to the list of the world’s most endangered animals. This would give the species the highest level of protection under CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). But this protection would also make it possible to combat the illegal trade that threatens the species.
The Hippopotamus is already listed as an Appendix II species, which means that they are not in danger of extinction, but could become so in the next few years if their plight does not improve.
Finally, the IUCN (International Union for Conservation of Nature) has already classified the species as vulnerable on its red list.
What role do hippos play in dispersing seeds and regenerating aquatic plants?
Like many other African species, the hippopotamus contributes in its own way to the balance of the ecosystem around it. Through its faeces, the hippopotamus encourages the flow of silicon into lakes and rivers. This mineral is no less vital for certain terrestrial and aquatic organisms (algae, diatoms, water sponges) than it is for climate balance. Indirectly, through plants, silica controls part of the carbon cycle and therefore certain carbon sinks.
how does it happen?
This distribution of silicon by hippopotamuses is easily explained by their lifestyle. They feed at night on dry land before returning to the water during the day, where they excrete their faeces. According to research, their faeces modulate up to 76% of the total flow of silicon, thereby promoting the development of the food web and carbon fixation.
Their presence is therefore essential to the survival of many plants and microplankton in Africa.
How do hippos communicate?
Ethnological studies in recent years have revealed some interesting facts about how hippos communicate.
Hippos use voice recognition to manage their group relationships.
The sound frequencies they emit tell them whether the animal in front of them is a stranger or not.
The animal responds in various ways. An approach, a cry or even a jet of excrement can be emitted in response to an animal’s call.
Throwing excrement allows them to mark their territory, as many animals would do.
Although the Hippopotamus appears to be idle during the day, it is actually when it is lurking in the water that it pays the most attention to its environment and the individuals in it.
Even more surprisingly, voice recognition also enables hippos to distinguish between their fellow hippos and the groups to which they belong. In this way, it could determine whether a hippopotamus on the riverbank belonged to a rival clan or to its own group.
Where can I see hippos in Congo Brazzaville?
The great efforts made by certain African countries to protect the hippopotamus have led to the creation of numerous reserves where the animal can be observed.
The Lefini reserve in the Republic of Congo and the Nouabalé-Ndoki national park are natural sites protected by the government where Hippos can be observed in their natural state.
During the safari cruises offered by Expéditions Ducret, it is possible to observe hippos in many places along the Congo or Sangha rivers.
What place do hippopotamuses occupy in African culture?
Given its age-old presence on African soil, the hippopotamus has been given a place in the continent’s stories and myths. These traditions, which are largely passed down through stories and tales, have given the animal a divine place.
It is the female animal in particular that has been given this honorary title. In African mythology, she was known as Tawaret, the goddess of fertility and childbirth in ancient Egypt.
This legend dates back to ancient Egypt. Tawaret, or Taouret as it is pronounced, meaning “the great one”, is a hippopotamus goddess standing on her lion-like hind legs and holding a hieroglyphic sign meaning “protection” in her human hands.
This hybrid appearance, a cross between different animals and humans, is intended to symbolise several aspects, such as fertility, but also the ferocity of a mother defending her son.
The obsidian knife that accompanies it in some of these representations symbolises fertility. The obsidian knife was once used to cut the umbilical cord.
Finally, its reddish-brown skin colour is thought to represent women’s menstruation.