More than two decades after the death of Pablo Escobar, Colombians are still seeing the ripples of his criminal empire. But it’s probably not what you think—it’s hippos. The notorious drug lord’s sprawling estate, Hacienda Nápoles, in the town Puerto Triunfo had in its heyday its own menagerie of exotic animals. Most were relocated to zoos after Escobar’s death, but a few hippos were left behind. Over the years, the hippo colony has grown to as many as 60. That’s 60 very large, territorial, dangerous animals with no natural predators that are making their homes around the various lakes in the community. They’ve also become a tourist attraction.

“I’ve observed that Colombians are very casual about them and seem relatively unafraid,” says UC San Diego Division of Biological Sciences Professor Jonathan Shurin, who has been studying Colombia’s hippos for the past two years. “People in Africa are terrified of hippos. They won’t go near a lake or river that has them. Colombian people seem very nonchalant about them.”

Shurin is working together with postdoctoral researcher Natalie Jones and Associate Professor Nelson Aranguren-Riaño of La Universidad Pedagógica y Tecnológica de Colombia to determine how the hippos are affecting ecosystems in local lakes and the Magdalena River. “This was a great opportunity to study something that had never been studied before,” Shurin says. “Evaluating the ecosystem impacts of the world’s largest animal living outside its native range is something you don’t often get to do.”