After it was swept away

'After it was swept away and lost its mother, the hippo was traumatized.

It had to look for something to be a surrogate mother.

Fortunately , it landed on the tortoise and established a strong bond.

They swim, eat and sleep together,' the ecologist added.

'The hippo follows the tortoise exactly the way it followed its mother.

If somebody approaches the tortoise, the hippo becomes aggressive,

as if protecting its biological mother,' Kahumbu added.