As our small boat wended its way up the Wami River in Saadani National Park, Tanzania, we passed a crocodile basking on the bank. Nothing unusual about that, but this croc only had three legs. I asked if one leg had been chopped off by a boat's propeller? "No," said our guide, Eliona Sabaya, "It was bitten off by a hippo."
Here was dramatic, amputee-reptilian evidence to illustrate a well-known factlet about Africa: that hippos are the most dangerous (non-human) animals on the continent, responsible for the deaths of more people than lions. Actually, let's say that hippos are the most dangerous mammals: Malaria-spreading mosquitoes cause many more deaths in Africa than hippos.
That observation was, however, of little comfort as we encountered a family of hippos wallowing in the center of the shallow river.