The pace of the pachyderms

Another excerpt from The Speed of Nearly Everything. My delightful commissioning editor said that it should be "suitable for reading on the john", and then said there was no need to explain that.

The classification of animals and plants always involves a bit of opinion, and that can sometimes cause confusion. Aristotle did not exactly see that whales and porpoises were mammals, but he knew they were not like fish. Linnaeus, who invented our classification system, listed whales and porpoises as fish in the first ten editions of his book, Systema Naturae.

Asian elephants, Minneriya, Sri Lanka, pachyderms to scholars of old.

In the same way, 19th century scientists grouped elephants, rhinos and hippos as pachyderms. These were big, had thick grey skins, and came from Africa, but the grouping logic made as much sense as linking worms and wombats because they burrow, or butterflies and birds because they fly.

Still, the pachyderms were big and they had a formidable approach to threats: they charged them down. The pachyderms were big and heavy enough not to fear anybody or anything. They still are.

A rhinoceros will charge for short distances at 40 to 50 km/hr (25 to 30 mph), as timed by chargees in motor vehicles. Black rhinos (think of them as dark grey) have poor vision, and often break off, or run into a tree, but they are also very good at changing direction, which takes all the fun out of being charged. They tend to be aggressive to each other, and may keep up their charging speed for some time when chasing other black rhinos.

Hippos can certainly outrun a human on land, though estimates of their speed vary between 30 and 50 km/hr (18 to 30 mph). The hippos are vegetarians, but that does not seem to stop them attacking and killing humans: they have a reputation for killing more people in Africa than lions, though the Cape buffalo is also a contestant there. The good news: hippos can’t jump, but you need to choose a thick tree, and hand go on!

Further reading for extreme taxonomists: look into the Whippomorpha.