Last year Stan took us through the Big Five – elephant, lion, leopard, buffalo, and rhino. I’ve been in the bush for the past few weeks and lucky enough to have wonderful sightings of all of these. But I do feel one animal has been very short-changed and it’s an animal very close to our hearts (i.e. Stan’s heart and my heart). That is the hippo. I’m sure readers of this blog know that kubu is the Setswana word for hippo, and that our detective has that as his nickname. I think the hippo has every right to be included in the top rank with those other five. Not only are the animals very large – the males weigh in over 4,000 lbs, coming in third to elephants and rhinos in terms of size, but they are also fierce and can be quite aggressive in some circumstances – they account for more human deaths in Africa than any other mammal. And they are fascinating creatures and interesting to watch, edging out the rhino for second place of the three ultra-large herbivores in my opinion. No river in Africa is complete without their cheerful grunting carrying across the water.
From a physiological point of view, the hippo is amazing. How about an animal that spends its days in the water, but is too dense to float? That can hold its breath for up to five minutes. (Don’t try that one at home!) That has nostrils designed to close under water, and a reflex that allows it to sleep under the water and rise for breathing without waking up. That has built in goggles (transparent membranes that close over the eyes under water). And that has built in sunscreen (the hippo secretes an oily brownish substance which protects its bare skin from the sun). Pretty impressive design, I’d say. And no rude comments about it being porcine. (Kubu would be particularly offended.) The hippo’s closest relations are the dolphins and whales; it separated off from them about fifty million years ago.
Most of the day they spend fully submerged or comfortably beached on a sandbar warming in the sun (having applied sunscreen, of course.) In the evenings they come out of the water and spend the nights browsing and grazing along the river banks or quite far inland if the feeding conditions are poor as they tend to be in the winter. At this time they are busy with the important issue of building up that 4,000 lbs of bulk, and you really don’t want to interfere with them. In particular, you don’t want to give them the idea that you are trying to cut them off from the haven of the river. That usually leads to aggressive behavior and possibly one of those human deaths.
I’ve had my own close encounter, mostly my own fault. It was my first time in a canoe on the Zambesi river in Zimbabwe. I was with a friend who was a bit more expert as a canoeist than I was, but not much. He was at the back. At a certain point the guide who was ahead of us in another canoe signaled us to move out into the center of the river; he’d spotted a pod of hippos near the shore. What he didn’t know was that the hippos had spotted him, and submerged and politely moved to the center of the river to let us pass. My friend and I paddled out into the river, proud of our calm expertise. Moments later a huge jaw opened a short distance in front of us; we had not reciprocated the hippos polite behavior. We immediately put the canoe into what we thought was reverse. Unfortunately our expertise did not run to reverse against the current. What we did do was cause the canoe to rotate as the current took us towards that enormous mouth. At the crucial moment the hippo sank under the water and we passed over it. I think I know why it didn’t convert our canoe into splinters and us into mincemeat. It was laughing too much.
Hippo behavior is complex. The males have water territories, but will tolerate other bulls as long as they behave in a submissive way. Last week we saw an interesting example at one of the dams at the game reserve where we were staying. The dam is large and a family of five hippos, one male and two females with youngsters, has taken up residence. They’re a charming group, and most days we would pop in to see how they were getting on. As I mentioned last time, on one occasion they had a stand-off with nine lions and eventually the hippos got right of way. On our last evening, we arrived at the dam to discover that it now contained six hippos. Apparently another male had decided the dam was a nice spot to spend the day. The altercation between the males seemed to involve bursts of rivalry where they would rise from the water bellowing and threatening each other by matching their enormous mouths. Then all would go quiet for a while and one would rest its head on the other’s back. Maybe that’s submissive behavior? Unfortunately it became too dark and rainy to see what happened in the end, but I’d guess that all six went off feeding and that the interloper would have found a more peaceful dam or river stretch for his day nap.
So from all points of view, I believe that the hippopotamus fully deserve a place up there with the other big five. I propose that in future we have the Big Six.
Michael – Thursday.