They don’t look particularly aerodynamic.
But scientists have discovered that hippos are able to become airborne for significant periods of time.
When trotting fast, their feet leave the ground for up to 0.3 seconds at a time, a new study has found.
And we have the folk at Flamingo Land zoo, at Kirby Misperton, to thank for this discovery.
Research from the Royal Veterinary College (RVC) discovered that unlike most large land animals, hippos almost exclusively trot, with the fastest ones taking to the air.
Previous studies have suggested the animals often use a standard four-footed (quadrupedal) walk.
Before now, researchers have not identified whether hippos become airborne when they move quickly, as is the case with other mammals, such as horses, but less common among larger animals.
Prof John Hutchinson from the college, and former RVC undergraduate student Emily Pringle, collected video footage from Flamingo Land Resort in North Yorkshire, recording how two hippos moved in their paddock during the day.
They also sourced video footage from the internet of hippos moving, providing a broader range of behaviour and movements compared to those in captivity.
Analysing the data, they found that unusually for land animals, hippos almost exclusively trot – even when slowly walking or quickly running.
Prof Hutchinson, who’s professor of evolutionary biomechanics and lead author of the study, said: “It’s hard to work with hippos as they tend to stick to the water and very seldom are trained to be studied in zoo collections.
“They’re also very dangerous. That’s part of the reason why science knew little about how hippos move before our research.
“We’re thrilled to provide the first study purely focused on revealing how hippos walk and run.
“We were pleasantly surprised to see how hippos get airborne when they move quickly – it’s really impressive.”
Kieran Holliday, science and conservation officer at Flamingo Land Resort, said: “Understanding more about the species we work with will only help us to improve the care we can give them in the future.
“And the fact that this paper has uncovered possible new discoveries into hippo locomotion could have positive impacts to the wider zoo community in regards to husbandry and enclosure design.”