Total length: 3.4-4.2m
Shoulder Height: 1.5m
Tail length: 30-50cm
Weight (mass): 1,000-2,000 kg (males), 1,000-1,700kg (females)
IUCN Red List Status: Vulnerable
Population Trend: Stable
Population numbers: estimated at 115,000 – 130,000 individuals
Hippos are semi-aquatic mammals, spending most of their day in water. They are large animals, with smooth, hairless skin, short legs and a very large head. The mouth contains huge tusk-like canines, although these teeth play no part in eating activities, but are used for attracting mates and showing strength to competing males in dominance battles.
Hippos are now only found to the northern and eastern parts of southern Africa, only extending as far south as the KwaZulu-Natal at present, however they were previously found in Cape Town, along the southern coastal belt and along the entirety of the Orange River until colonial settlers hunted them out of those areas. The distribution of hippos is patchy across the rest of sub-Saharan Africa, but they are widespread.
The type of habitat required by hippos is a sufficient water supply so that they are able to submerge themselves. They show a preference of permanent waters containing a sandy substrate. They can be found in rivers, dams and lakes. They feed on grass, and so the surrounding areas from the water must have a suitable supply.
Hippos, as I’ve previously said, spend a lot of time in water, however, in winter, they spend a significant amount of time lying up on sandy or muddy banks, mostly to be in the sun. Most often, hippos will be found in pods containing 10-15 individuals, however larger groups and lone bulls are not uncommon.
The pods are usually made up of cows and their calves of varying ages with a dominant bull in charge of the group overall. The territories of hippos tend to be narrow in the water, but broaden out on the grazing grounds. Dominant bulls scatter their dung to mark their territory. The scattering is done by flicking the tail from side to side, very fast and vigorously, they will spread their dung onto rocks, bushes and other objects, as well as in the water.
Adult hippos are able to stay under water for around 6 minutes. They are able to close their nostrils and ears to stop water getting in.
The skin glands on hippos secrete a reddish fluid, which is often mistaken for blood, however it is most likely used as a skin lubricant and moisturiser. Hippos have very sensitive skin which can easily burn if exposed to the sun for too long, which is why they tend to come out of the water to feed at night-time.
Hippos are very vocal creatures, and you will often hear their grunts and snorts. The only way to describe their grunts is that they sound like very large frogs or toads, or an evil old man laughing slowly and cunningly.
If hippos are provoked, they become extremely dangerous to be near. The ones to be particularly careful of are solitary bulls, or cows with young calves. They are estimated to kill around 500 people a year in Africa, giving it the reputation of the world’s deadliest large land mammal. Make sure you give these magnificent creatures enough space so that they don’t feel threatened by your presence and they won’t harm you at all.
Hippos mate in water, due to their size I imagine this is easier on the females. They have a gestation period of 225-257 days, where they will then give birth to a single calf weighing 25-55kg (usually around 30kg). The cows give birth on land in dense cover where they will then remain separated from the pod for about 2 weeks. They aren’t known to have a breeding season as calves are seen to be produced at any time of year, however there does appear to be a large increase and a seasonal peak in October to March.