Do hippos really kill more people than lions?

You will hear it on your first game drive: "The hippo is Africa's most dangerous animal. It kills more people than lions, elephants and crocodiles combined, about five hundred a year." It is a good line. Is it true?

Where the number comes from

Nobody knows. The figure of 500 hippo deaths a year appears in countless articles, and none of them cite a source, because there is no central count of animal attacks across Africa. Deaths happen in rural areas, are recorded locally if at all, and are never added up. The 500 figure is best understood as an old estimate that has been repeated until it became a fact. The same is true of most of the numbers in "deadliest animal" lists, with the honourable exception of mosquitoes, where malaria deaths are properly counted.

What we do have are local studies. In Tanzania, Craig Packer and colleagues documented 563 people killed by lions between 1990 and 2005, around 35 a year in one country, with a sharp increase over the period. That alone makes "22 lion deaths a year" for the whole continent, another number that circulates without a source, obviously too low. Hippo attacks are reported regularly from Kenya, Tanzania, Zambia, Malawi and Mozambique, especially from fishing communities on lakes and rivers, and in some places they are clearly the leading cause of wildlife deaths. Whether the continental total is 500, or 200, or 1,000, nobody can honestly say.

What is true

Hippos are genuinely dangerous, and for understandable reasons. They are enormous, fast on land for short distances, territorial in the water, and they leave the river at night to graze, which puts them on the same paths that people use to fetch water or walk home after dark. A hippo surprised between you and the water is a serious problem. Most attacks involve small boats on rivers and lakes, or people walking at night near the water. Almost none involve tourists in vehicles.

Lions kill people too, in a pattern driven by where people and lions share land, mostly along the edges of parks and in areas where prey has been hunted out. Crocodiles probably kill more than either, and elephants, in places where crops meet herds, more than most people assume.

The honest version

"Hippos kill a lot of people every year, mostly fishermen and villagers near the water, and they deserve a wide berth. Nobody has a reliable total, and anyone who gives you one to the nearest hundred is guessing." Less snappy, but it has the advantage of being true. On safari, the practical point stands: do not walk near water at night, give hippos their path to the river, and listen to your guide.