In 1872, Leland Stanford, founder of Stanford University, enlisted the help of eccentric inventor Eadweard Muybridge to settle a debated question: did a trotting horse ever have all four feet off the ground at once? Muybridge, an accomplished photographer, captured blurry images of a horse in mid-trot, demonstrating that the naked eye can’t easily perceive rapid, subtle movements.
His work contributed to the development of cinematography and included photographing various animals in motion, though he did not capture hippos. Regarding hippos, Muybridge speculated that their fastest gait on land was likely an amble, possibly a trot, but with minimal or no time of having all feet off the ground.
Was Muybridge correct? As a scientist whose research focuses on how giant land animals like rhinos, elephants, and giraffes move and how gravity uniquely affects their athleticism on land, there has long been curiosity about how hippos move on land.
Most people likely think of hippos in terms of their activities in the water, where they spend much of their time. However, as amphibious animals, hippos also spend about one-third of their time on land. Given their massive size—typically around 1400 kg, similar to young elephants—it might be expected that hippos would be ponderous and slow on land, particularly since they are adapted for aquatic life and appear bulky.
What seems probable and what is true can differ, which is where science comes in to provide evidence-based answers. While it’s clear that hippos cannot fly due to their size and lack of wings, the real question is what they can achieve under the force of gravity.
In a recent study, it was demonstrated that hippos can trot and, at high speeds, can actually lift all four feet off the ground simultaneously. This finding is notable because it reveals that hippos, despite their large size and semi-aquatic lifestyle, are among the largest animals capable of becoming airborne at high speeds.
Basic experiment
Reviewing the existing literature on hippo locomotion revealed uncertainty about the range of gaits and footfall sequences used by hippos.
Some studies indicated that hippos used a “lateral sequence” walking pattern—a “four-beat” gait where the sequence of footfalls is left hind, left fore, right hind, and right fore.
Other studies suggested that hippos only employed a “trotting” pattern even at slower speeds. In this context, trotting refers to a “two-beat” gait where the diagonal limbs move almost simultaneously left hind and right front feet touch the ground, followed by right hind and left front feet, with a slight interval between the two pairs.
Few scientific studies had investigated hippos’ movement at high speeds on land. Observations indicated that hippos might trot at moderate speeds.
To explore this, a straightforward experiment was designed, similar to Muybridge’s approach but using modern technology: recording digital videos of hippos moving at various speeds.
Undergraduate veterinary student Emily Pringle was sent to Flamingo Land Resort in North Yorkshire, UK, equipped with basic GoPro cameras to capture footage of the two adult hippos.
Over two days of intermittent filming, she observed that the hippos were moving slowly, primarily walking. This was expected, as the hippos spent little time on land and could not be encouraged to move quickly—they lived a secure life.
As a secondary approach, internet searches for wildlife videos were conducted to find additional footage of hippos moving at different speeds. This broader data set provided context for the videos from the zoo, and some footage of hippos moving quickly under more natural conditions was successfully located.
Evidence from video
A total of 169 strides were collected from 46 video clips featuring 32 hippos. Although most footage showed slow walking, all walking strides displayed trotting patterns, indicating that hippos prefer trotting over a four-beat lateral sequence pattern, even at slower speeds.
The most notable finding came from videos of wild African hippos and a few from zoos. About 14 of the 46 videos showed brief instances of “non-support,” where hippos were airborne with all four feet off the ground.
The fastest sequences showed hippos becoming airborne for approximately 0.3 seconds. Although this may seem very brief, it exceeds the time a single foot might be on the ground (as short as 0.2 seconds). Additionally, because a large animal like a hippo has a delayed nervous system response to stumbles, these airborne moments could be risky.
These findings highlight the unique nature of hippos’ land locomotion. Unlike most other mammals, especially larger ones, hippos maintain a trotting gait across various speeds. While exact speeds were not measured, it is hypothesized that hippos are likely not much faster than elephants, which have been shown to move at up to 25 kph with a lateral sequence “amble,” without becoming airborne.
Hippos’ ability to become briefly airborne indicates they are relatively more athletic than elephants. However, they are less agile than white rhinos, which can also be as large as hippos but can gallop and achieve airborne movement, likely at higher speeds. This range of locomotor abilities, observed in other large animals such as giraffes and even extinct dinosaurs, reveals two key patterns.
First, even at sizes exceeding 1,000 kg, there is still a range of athletic capabilities, such as moving faster than a slow walk or becoming airborne.
Second, as size increases, there is an inevitable decline in maximum speed. Larger animals must sacrifice some athletic abilities, like becoming airborne, in exchange for the advantages of their greater size.
