CNN — Colombia plans to fly dozens of its “cocaine hippos” – the descendents of drug trafficker Pablo Escobar’s private menagerie – to new homes in India and Mexico in a bid to control their booming population, according to the local governor. There are now between 130 and 160 of the hippos, according to the Colombian government, and they have spread out far beyond Escobar’s former ranch of Hacienda Napoles, where they began as a population of just one male and three females. The original hippos were part of a collection of exotic animals Escobar had amassed in the 1980s at his ranch about 250 kilometers (155 miles) from Medellín. After his death in 1993, authorities relocated most of the other animals, but not the hippos – because they were too difficult to transport. But the have since begun to reproduce rapidly, extending their reach along the Magdalena River basin, and they now pose an environmental challenge and are concerned nearby residents, authorities say. urnal Nature warned their numbers could balloon to 1,500 within two decades. Previously, authorities have tried to control their population using castrations and “shots” of contraceptive darts. But the contraceptive drives have had limited success. Now there’s a plan to 70 hippos to natural sanctuaries in India and Mexico, the governor of Antioquia province, where Hacienda Napoles is located, said in a Tweet. A total of 70 hippos, a mix of males and females, are expected to be moved – with 60 going to India and 10 to Mexico. The technical term for this operation is “translocating,” governor Aníbal Gaviria explained in an interview with the Colombian outlet Blu Radio, as it would involve moving the hippos from one country that was not their native habitat to another that was also not their natural habitat. The goal was “to take them to countries where these institutions have the capacity to receive them, and to (home) them properly and to control their reproduction,” Gav iria said. Sending the hippos back to their native land of Africa was “not allowed,” Gaviria said. Sending the hippos back to Africa risked doing more harm than good, for both the hippos themselves and the local ecosystem, María Ángela Echeverry, professor of Biology at the Javeriana University, previously explained to CNN. “Every time we move animals or plants from one place to the other, we also move their pathogens, their bacteria and their viruses. And we could be bringing new diseases to Africa, not just for the hippos that are out there in the wild, but new diseases for the entire African ecosystem that hasn’t evolved with that type of disease,” Echeverry said. Aside from reducing the number of hippos in Colombia, authorities are hoping to learn how to manage the remaining population, which are recognized as a potential tourist attraction. The hippos will be flown in purpose-built boxes, Gaviria said in the radio interview, and will not be sedated at first. But “emergency sedatio n” is possible if one of the animals is overcome by nerves during the flight, he added. The translocation could be completed by the first half of this year if necessary permits are expedited, especially from the Colombian Agricultural Institute, Gaviria said. Hippos are seen by some as an invasive species that can pose a danger to local ecosystems and sometimes even to humans. Research has highlighted the negative effects hippo waste can have on oxygen levels in bodies of water, which can affect fish and ultimately humans. Nature magazine cited a 2019 paper that found lakes where hippos were present had more cyanobacteria, which are associated with toxic algae. These blooms can reduce water quality and cause mass fish deaths, affecting local fishing communities. Hippos can also pose a threat to sa agriculture and , according to a Biological Conservation study published in 2021. Hippos can eat or damage crops and engage in aggressive interactions with humans. “Hippos live in herds, they are quite aggressive. They are very territorial and are plant eaters in general,” said Professor Echeverry. While the “cocaine hippos” are not native to Colombia, the local terrain is thought to be favorable for their reproduction, since it has shallow water sources and a large concentration of food. Until now, Colombia has not been able to solve a problem that – in the words of Gaviria to Blu Radio – “got out of control.” Whether the latest efforts will succeed where birth control efforts failed remains to be seen.