A 2009 study researched how hippos move underwater. By analyzing underwater video footage, the researchers discovered that hippos do not swim like most aquatic mammals. Instead, they push off the riverbed using their legs in a motion similar to galloping or bounding. Their natural buoyancy reduces the effective force of gravity, allowing these massive animals to move in ways that would be inefficient or impossible on land.

Hippos spend much of their daily activity in water, and as temperatures rise, they spend even more time in pools. In 2020, a study examined how hippos use water to regulate their body temperature. The researchers observed three hippos in their zoo enclosures over six months, recording hourly water and air temperatures and correlating these with the animals’ locations and activities. The study found that water temperature influenced pool use far more than changes to the pool size itself. These findings also aligned with broader observations of hippo behavior in previous research.

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