(CNN) — Hippos can take off when moving at high speed over land, according to a new study.

This is the first time that the animals, which can weigh more than 2,000 kilograms (2.2 tonnes) and spend much of their time in the water, have lifted all four limbs off the ground during rapid movements, according to a statement from the Royal Veterinary College (RVC) in the UK.

After analyzing videos showing 169 movement cycles of 32 hippos, researchers found that the fastest-running animals spend about 15% of each step above the ground.

John Hutchinson, lead author of the study and professor of evolutionary biomechanics at RVC, told CNN that very little is known about how hippos move on land.

“Hippopotamuses were a big missing piece of the puzzle,” he said. “They're really hard to study.”

Not only do they spend a lot of time in the water, they are also “very aggressive and dangerous” and more active at night, Hutchinson said.

In the videos the researchers examined, hippos tended to move quickly when they were motivated to do so, such as when chasing a rival hippo or being chased by lions or rhinos, he said.

The team also found that regardless of their speed, hippos almost exclusively walk at a trot – with two diagonal limbs moving simultaneously in the same direction, followed by the other two diagonal limbs. Other mammals, such as horses, however, change from walking to trotting and then to galloping depending on their speed.

“Hippos are one of the very few animals that simply trot,” said Hutchinson. “It was a pretty interesting find.”

The findings could help improve the treatment of hippos in captivity and detect and monitor whether hippos develop physical problems, Huntchinson said.

A sample video showing a baby pygmy hippo galloping served as a starting point for future research for Hutchinson, he said. He wants to investigate whether small hippos, such as baby hippos and baby pygmy hippos, can gallop but lose the ability as they get older.

The study was published on Wednesday in the journal PeerJ.