You’re low to the water, in a flat-bottom canoe called a mekoro. Three metres away, a bow wave is moving toward the boat. It’s the only visible sign that an enormous bull hippo is running underwater, along the narrow river bed towards you. He’s bent on protecting the four females that make up his pod– three minutes ago, when your boat edged into this particular elbow of the river, he lifted his whole body of the water in a breach, a spectacular, unmissable warning. Just before he went under the water, he opened his massive jaws wide and roared, a sound that reminds you not just a little bit of Jurassic Park. You’ve entered his territory and he wants you out.

Photo by @shahselbe

This will end in one of two ways: the hippo will come up under the boat, jaws open, and will crush the thin fiberglass hull below you like paper. You and every piece of gear will be in the water, with an angry hippo and unknown number of Nile crocodiles and things will very likely end with a medivac. Or, this could be a very convincing bluff.

You’ve been on the river for thirteen straight days, sometimes drifting through dreamlike stands of emerald papyrus, sometimes pulling fully-laden boats through knee deep, leech-infested mud. The sweet smell of decomposing vegetation, of elephant dung and water lilies. It’s true that you started the expedition with a vaguely Disney-related fondness for the hippo, but things have changed. The stated purpose of your expedition is to assess biodiversity in the Delta. In reality this trip has been an exercise in hippo management.

Hippos are without a doubt the most dangerous animal in Africa, doubly so when you are on the water with them. A male can be twelve feet long and weigh more than three and a half tons — think of an angry minivan. The hippo has evolved to be perhaps the meanest grass-eater on the planet: their ferocity comes from a perfect combination of territoriality and teeth. Hippos use their gums to pull up the 88 pounds of grass they eat each night, so those teeth are there only to defend; against other hippos, and against anything else that might be stupid enough to encroach on their domain. You can recognize older hippos by the deep scarring on their backs from countless violent battles.

Hippopotamus amphibeus is often described in literature as mostly herbivorous. Mostly. This is the word that is ringing in your head as that wave approaches.