Colombia's 'cocaine hippo' population is even bigger than scientists thought [View all]

02 June 2023

The most comprehensive census yet reveals that there could be twice as many of the invasive animals than previous estimates indicated.



Wild descendants of the hippo population introduced in Colombia by Pablo Escobar.Credit: Raul Arboleda/AFP via Getty

Colombia’s invasive hippo population is even larger than researchers had thought, according to the most thorough census of the animals conducted yet. Scientists were already concerned about the hippos — considered the largest invasive animal in the world — threatening native plants and animals in the country, and had been calling for drastic measures to reduce the population. The census results have only heightened that fear.

A few years ago, researchers estimated how fast the animals were reproducing, to project that about 98 hippos were living along the country’s Magdalena River and its tributaries in 20201. But the new study, for which a research team counted the animals in person, by drone and using other tracking methods, estimates that there are 181–215 of them residing in Colombia.

“Before, one argument against dealing with the hippos was that our information was limited and our arguments theoretical,” says ecologist Rafael Moreno, who participated in the study while at the Alexander von Humboldt Biological Resources Research Institute in Bogotá. “But we have put that argument to bed now. This study shows that this is a real issue, and that the state must act urgently.”

By drone and on foot
Colombia’s ‘cocaine hippos’ are all descendants of three females and one male illegally imported by drug-cartel leader Pablo Escobar. After he died in the 1993, the hippos (Hippopotamus amphibius) escaped from his estate and established themselves in the Magdalena River. Without the natural predators or droughts of their native Africa to keep them in check, the giant herbivores have bred rapidly to form the largest population of the animals outside that continent.

More:
https://www.nature.com/articles/d41586-023-01818-z