The Colombian government has announced a raft of measures to control its growing population of invasive hippos—descendants of animals introduced to the country by the notorious drug lord Pablo Escobar. Hippos are native to Africa, but in the 1980s, Escobar smuggled four of the animals into Colombia, keeping them at his luxurious country estate, Hacienda Nápoles, in the municipality of Puerto Triunfo—located east of Medellin—which featured a private zoo. As well as the hippos, the zoo housed numerous exotic creatures, including elephants, ostriches, rhinos, giraffes and zebras. Following the death of Escobar, who was killed by Colombian police during a...