As a solo circumnavigation it will never make the history books, but the circuit Ellen the pygmy hippo makes of her pool has got zoologists puzzled.

For most creatures of this endangered species prefer dry land. Which is why the keepers of Ellen at Edinburgh Zoo have named the hippo after Ellen MacArthur.

‘Ellen loves the water, just like her namesake, and spends a lot of time paddling about in the pool,’said Kathleen Standen, a senior keeper at the Scottish zoo.