When drug kingpin Pablo Escobar died in 1993 having built a billion dollar cocaine empire, he left behind a zoo. While his rhinos, giraffes, elephants and kangaroos were re-housed, the hippos were left in Escobar’s abandoned ranch in the Colombian countryside.

In 2007 they started turning up 100 kilometres away, frightening fishermen. Vet Carlos Valderrama was called in to tackle the problem. He describes to Josephine McDermott his experience of the first ever castration of a hippo in the wild.

(Photo: Carlos Valderrama castrating the hippo. Credit: Carlos Valderrama)