When Gina Paola Serna studied to become a biologist and veterinarian in Colombia, she never expected to one day be tasked with neutering an invasive herd of hippos that once belonged to Pablo Escobar.
When they were smuggled into the drug lord’s private zoo in the 1980s, there were just four hippos. But in the 26 years since Escobar’s death, their numbers have steadily grown : the herd now includes about 80 animals – threatening to disrupt ecosystems in Colombia. So now, Serna spends her days tracking and sterilizing the hulking riverine mammals.
“The first time I worked with a hippo I was terrified – these are animals way bigger than we are used to working with in Colombia,” Serna said, before another day in the field. “These are massive and territorial animals, so everything is complicated when it comes to working with them.”
The so called “cocaine hippos” were illegally brought to Colombia and kept in a zoo Escobar built on his vast Hacienda Nápoles estate, along the River Magdalena. He brought rhinos, giraffes and zebras to his menagerie. Oral history suggests his associates were wowed by his collection of spectacular beasts of the wild, which included about 200 animals.
But after El Patrón was shot dead by police on a rooftop in his hometown of Medellín, Colombian authorities seized his estate and the animals on it. Most were shipped off to zoos, though the logistics of moving the four hippos – each weighing well over a metric ton – proved insurmountable, and they were left to wander the Andes.
As many as 24 hippos have been sterilized so far, using Gonacon, an immunocontraceptive vaccine, which works temporarily but can cause permanent infertility. Originally, there were calls to cull Colombia’s hippo population, but in the end, sterilization was thought to be the more humane option.
“Obviously you can’t let these hippos keep reproducing, which is what they’ll keep doing because they are in paradise,” said Enrique Zerda Ordóñez, a professor of biology at the National University of Colombia in Bogotá, adding: “They’ll always have water, all the plants they could ever want to eat, and they can pop out of the river and eat grass with the cows.”
Rural farmers have grown fond of the wandering herd, charging tourists for a glance at the hippos that bathe on their lands, though one villager was injured last year after getting too close. Animal rights activists and conservationists have also sought to protect the hippos, vehemently protesting any initiatives to cull the animals.
“This is only a pilot project, but something had to be done,” said Robin Poches, a biologist and businessman who helped the Colombian government secure a donation of 70 doses of Gonacon from the United States Department of Agriculture. “Otherwise it’s only a matter of time before someone gets seriously injured or killed.”
The decision to medically sterilize the animals, rather than castrate them, will save money and time-consuming work.
Castrating a hippo is no small feat, and costs about $7,000 for each animal. Hippos spend most of their time submerged in rivers, grazing on underwater flora, and only emerge at night, so the surgery would have to be performed after dark. A hippo’s reproductive organs are internal, so veterinarians have to carry out invasive procedures in order to neuter the animals.
“The surgery itself isn’t the most complicated part – the tricky thing is anaesthetising them,” said Serna, who has castrated six hippos from the herd, knocking them out with tranquilizer darts that pierce 5cm (2in)-thick skin. “It requires a whole team of people and as we don’t have those drugs for such enormous creatures available in Colombia, it is very expensive.”
The hippos are one of many enduring holdovers of Escobar’s reign of terror, which spanned from the late 70s until his death in 1993 and brought widespread murders and kidnappings. But for Serna, the animals should not be associated with the kingpin.
“The hippos are not Escobar’s legacy, they are simply animals that escaped and bred and made a home in an environment that is not their own,” Serna said. “So to me, they don’t have anything to do with Escobar.”