Hippos brought to Colombia as part of Escobar’s private zoo on his farm, Hacienda Napoles, have been reproduced so successfully that there are serious concerns about their environmental impact and human security, according to a new study by researchers from Mexican and Colombian universities .
Hippos have spread out from their original home, some 160 kilometers east of the city of Medellín, in the department of Antioquia, dispersing around the Magdalena River basin as their population continues to grow.
The study authors, published in the January issue of the journal Biological Conservation, recommend that hippos be euthanized to avoid long-term negative effects, but other scientists are calling for a castration program to control the hippo population, citing concerns about animals well-being and the attachment of some residents to their new neighbors.
In the 1980s, Escobar imported a hippopotamus and three female hippos to join his animal collection. After his death, other species of exotic animals were relocated, but the hippos were left because they were difficult to capture and transport, according to the study.
Hippos soon began to spread in the surrounding area, but government efforts to slaughter them were stopped after a public outcry.
Instead, a sterilization campaign was launched, but it did little to slow the hippos’ progress.
From 2011 to 2019, four males were spayed and two females were sterilized, but that “does not appear to have a major impact on reproduction,” according to the study.
Researchers say there are probably more than 80 hippos in the area today, up from 35 in 2012, and fear that hippos will continue to spread across Colombia if no action is taken.
The study also cites research that shows the negative effects of hippo waste on oxygen levels in water bodies, which can affect fish and, ultimately, humans, and raises concerns about the possible transmission of hippo diseases to humans.
Hippos also pose a threat to people’s livelihood and security in the affected areas, the study said, eating or damaging crops and engaging in aggressive interactions with humans.
The researchers cite incidents of hippos chasing people, as well as a hippo attack in May 2020 in which a 45-year-old man was seriously injured.
But while the study’s authors recommend killing, Enrique Zerda Ordóñez, a biologist at the National University of Colombia, believes that castration programs are the way to go.
Slaughtering hippos would be an “easy option,” said Zerda, but it could affect the survival of an endangered species in Africa.
Although sterilizing hippos is not an easy task, he said, he believes it is possible and necessary to do so now, before their number increases further, according to a university press release.
“At the moment, the authorities do not consider the species a problem,” said Zerda, “but in the future, when there are 400-500 hippos, this could pose a threat to the survival of other species that feed in the same areas. ”
David Echeverri Lopez, head of forests and biodiversity at the regional environmental agency CORNARE, told CNN that the situation is delicate.
“The option to kill them has always been on the table,” he said. “However, it is very difficult to imagine that this could happen at the moment.”
Although hippos are an invasive species capable of completely changing local ecosystems, people in the area have become accustomed to them, said Echeverri. They have become a tourist attraction for which people feel some affection, he added.
Some of the hippos will have to be killed, because it is “practically impossible” to locate and relocate or sterilize them.
“But there are some other animals that are located in certain areas, in lakes and places that allow the implementation of a birth control plan, as long as there are adequate resources,” said Echeverri, who works with the NGO Animal Balance to try to find solutions. alternatives.