
Hippo on the run (Photo Jozef020, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons)
Dear Readers, just because I am pretty much immobile (apart from the challenge of getting to the toilet on crutches) doesn’t mean that I’m not intrigued with animal locomotion. And so it was that yesterday I read this interesting piece about the hippopotamus. It seems to imply that at some point, when sufficiently motivated, a hippo can get airborne – i.e., all four of its legs are off the ground at the same time. This is quite a feat for such a heavy animal, and something that elephants aren’t able to do, though rhinos are apparently more gymnastic than hippos – maybe they have longer legs? At any rate, this all got me thinking about the things that we take for granted, and how animals are a constant source of wonder.
Back in the day, people used to think that horses got airborne, but got it completely wrong as to when.

Horse Race (Public Domain)
It took the photographs of Eadward Muybridge to capture the moment when a horse is actually airborne – at this point, all four legs are bent, rather than straight out like a rocking horse. You can see this clearly in the two central photos of the top row.

Scientists at the Royal Veterinary College in Hertfordshire studied captive hippos at Flamingo Land in North Yorkshire – a student was dispatched to video the hippos moving out of their night quarters and chasing one another around their paddock. When it was analysed, the film showed that the hippos really only have two gaits, the walk and the trot, but that they could get airborne at a fast trot, which happened up to 15% of the time.
Why study hippo locomotion, though? For one thing, it could give us insights into how those other giant land animals, the dinosaurs, moved. For another, understanding the biomechanics of movement can help with the medical needs of captive animals, and animals in sanctuaries. Furthermore, these are difficult animals to study – hippos are responsible for more deaths in Africa than any other large mammal, they are most active at night, and they spend the majority of their daytime hours in the water. Which brings us to another point. Hippos may seem ungainly on land, but in the water they are as graceful as a ballerina, even though they can’t actually ‘swim’ – their bodies are too dense for them to float, and so they either run along the bottom of a lake or river, or jump upwards to breathe. If you have six minutes to spare, I recommend this short BBC film on the hippos of the Okavango Delta. You won’t be disappointed!
And finally, a quick medical update – still in some pain, still taking my painkillers, still sleeping downstairs, but things are definitely improving all the same. This won’t be a quick fix, so I’ll have to be patient, but everything is moving in the right direction!



















