The River Horse!- Article by Gareth Jones

The River Horse: Hippos In Nairobi!

Some years ago, it was getting late on a cloudy day and almost becoming evening, and being tired after a long day, I rode slowly but purposefully through the park, not really putting extra effort into looking. Then suddenly a huge shape appeared from behind a bush on my right, it was a hippo feasting on the lush green grass that had grown after the recent rains. Clearly, the Hippo was not amused that “dinner” had been interrupted, and made short hippo grunts while running in half circles and then turning towards me, as if to say “come on, move away and leave me in peace!” Well, I did listen to the hippo’s “body language” message and left the massive beast to feast into the night.

On another occasion, early one morning I drove through the Langata Forest, on a chilly dull overcast day. Suddenly a huge shape appeared in an open area on my left, it was a hippo lying down resting, no doubt after a night of feasting on the lush green forest grasses due to the recent good rains. The hippo lay still for a few minutes but then stood up as another vehicle passed next to me, looking at me with an almost smiley bemused expression, the huge hulk of a hippo slowly turned and retreated into the thicker bush. Wow! what a great and unusual sighting to see such a “surprise guest” in the forest. I thought for a moment, how ironic it was that the hippo appeared to be “smiling” as a “hippo on the go”, while in fact, it is a very dangerous animal. A humorous thought came to my mind, “when considering that hippos are so very large and fat and all they feed on is vegetation, then Hippos are a living proof that the salads are fattening “Ha ha Ha”. The word Hippopotamus comes from the Greek and it means River (potamos) Horse (hippos). In some languages, the name has been translated to “river horse”.  In ancient times the hippopotamus was known to the Greeks and Romans as the “Beast of the Nile”.

The Hippo needs to resurface every 3 – 5 minutes to breathe. The process of surfacing and breathing is automatic, and even when sleeping underwater a hippo will emerge and breathe without waking. Hippo bulls can weigh well over 1,500 kg, they are the third biggest animal in Africa behind the elephant and rhino, and can run on land at speeds of up to 30 km per hour. Combine this with their aggressive nature, agility in and out of the water, and sharp, close to 500mm long teeth in enormous jaws and you can understand why hippos can make for such a fearsome creature to encounter.

Friday 18th of June 2010 was an interesting day, 3 lions had been eating on a buffalo carcass at the water’s edge of the Eland Valley Dam. When I arrived at the dam, the lions were sitting quietly on top of a mound, and the hippos were deep in the water, with the buffalo carcass visible on the opposite bank of the dam. I sat and watched them for some time, eventually, the Hippos began to move towards the buffalo carcass. The hippos came out of the water and stood over the carcass, from a distance it was difficult to see exactly what they were doing, but they appeared to be licking/muzzling the carcass on quite a few occasions. I then moved closer to the buffalo carcass by taking the backtrack past the dam wall, as I stopped the hippo retreated into the water, so I sat quietly and waited. After some time, the lions began to move towards the Buffalo carcass (a lioness with 2 sub-adult cubs), they each ate briefly on the carcass, and I could see they were all very full from the feasting. Then the hippos began to advance while the lions were at the buffalo carcass, they boldly came out of the water, and the lions immediately timidly retreated. The Hippos then repeated the cycle of licking & muzzling the buffalo carcass.

It was again difficult to see from where I was parked because the carcass was on the water’s edge and partly hidden by the bank, but I observed the hippos’ tongues licking the carcass. A truly fascinating event to witness, however, this did get me thinking. Firstly, how did the buffalo die on the edge of the dam? Was it alone at the time? Was it weakened so that a single lioness with 2 half-grown cubs could kill it? Did it die of another cause at the water’s edge? It’s hard to tell, then also the actions of the Hippos were really amazing and very rare to observe. Perhaps they were trying the get mineral nutrients like body salts etc from the buffalo carcass? Hippos are not known to eat meat. What is also particularly amazing is the location of this natural event in the Nairobi National Park, which was at the Eland Valley Dam is less than 1km from the park boundary, next to the Nairobi megacity.

Nairobi National Park has hippos in various dams and in the Mbagathi River. If people sometimes sit quietly at a dam where hippos are present, they often start to perform as they cavort in the water. Sometimes, small babies can also be seen. Even though hippos can look somewhat comical at times with green vegetation material on their heads, and we sing funny songs like “Mud, mud glorious mud, nothing quite like it for cooling the blood”, in reality, Hippos have a nasty reputation in Africa. This is mostly because of their aggressive nature when they are out of the water feeding, while people are collecting water in the early morning or late afternoons. The situation has become particularly tense in some parts of Africa where human populations have increased and water resources have decreased. With so many dangerous animals in Africa, many people often overlook the fact that hippopotamuses as a species are actually the biggest killers of humans out of all the large African animals. Although hippos are herbivores, these highly territorial animals are estimated to kill well over 500 people each year in Africa. Hippo bulls fiercely defend their territories, which include the banks of rivers and lakes, while females hippos can get extremely aggressive if they sense anything getting in between them and their babies, who stay in the water while they feed on the shore. The ‘yawning’ that Hippos often display is actually meant to be a threat.

Sometimes you will see a reddish tint from the skin of the Hippo. This is the body’s way of producing a type of natural sunscreen for protection from the heat. When it is coming off the body it is often mistaken for blood or for sweat but it isn’t either of them. Neither blood nor sweat, this secretion is a natural sunscreen that protects the hippo’s naked skin from the harsh African sun. Blood sweat is made up of two secretions: one red (hipposudoric acid) and one orange (norhipposudoric acid). The secretions serve two purposes, these highly acidic compounds inhibit bacteria (reducing disease) and absorb ultraviolet light (helping prevent sunburn and sun damage).

The average lifespan of a hippopotamus is between 40 and 50 years. Hippos are social and usually hang out together in groups of 10 to 30 individuals, but some groups may include up to 200 members. No matter how small or large a group, all hippo herds are led by a single, dominant bull. Many of these herds contain females, but bachelor hippos are allowed inside the community as long as they know to respect the bull hippo and not flirt with any of the females. Would you believe a hippopotamus cannot swim? You would think that an animal that spends a majority of its time in the water could swim, but hippos cannot. However, they can move underwater at a speed of 15 mph (8 km/h). So, you won’t be able to outswim them!

A visit to the Hippo pools in the park is a worthwhile and rewarding experience, there is much to see there including birds, monkeys, and other species, but please do not venture alone, hippos are dangerous creatures, armed rangers will escort you. Yes indeed! the hippo is another amazing creation, indeed the “river horse” has a fearsome reputation throughout Africa.