Hippos are incredibly cuddly. They are also famously violent. They spend their days laying on top each other in riverbeds but if you disturb them they will roar and kill you.
Left to their own devices, hippos live in Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, the Central African Republic, Chad, the Republic of the Congo, the Democratic Republic of the Congo, Côte d’Ivoire, Equatorial Guinea, Eswatini, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Kenya, Malawi, Mali, Mozambique, Namibia, Niger, Nigeria, Rwanda, Senegal, Sierra Leone, Somalia, South Africa, South Sudan, Sudan, Tanzania, Togo, Uganda, Zambia, and Zimbabwe—thirty-eight countries, all of them in Africa, because the hippopotamus is not cosmopolitan.
Places they do not, by nature, live: America. Canada. Mexico. Europe. All of Russia. All of Asia. Any islands.
They only live in Africa.
In 1981, Pablo Escobar looked at this situation and decided that it was not something he liked. He imported one male and three female hippos to his private zoo in Colombia—which, keen readers may recall, is not in the list of countries and is not in Africa. Four decades later, these original four have become roughly two hundred.
After Escobar was killed in 1993, officials dismantled the zoo and relocated the animals they could relocate. The hippos presented a difficulty, given they are giant and do not like being approached.
They were left behind. As one biologist put it, “It was logistically difficult to move them around, so the authorities just left them there, probably thinking the animals would die.”
The animals did not die.
From a hippo’s perspective, Colombia is alright. Kind of like Africa but with fewer hippos, food everywhere, warm water year-round, no punishing droughts, and no crowded pools to fight over.
The original four became roughly twenty-eight by 2009; by 2021–22, a census estimated between 181 and 215, 37 percent of them juveniles. The Environment Ministry now says the population has passed two hundred and, left alone, could reach five hundred by 2030 and one thousand by 2035.
“These hippos are a true nightmare,” a fisherman said after one lunged at his boat. On euthanasia as a potential solution, one restaurant owner says, “We don’t want to see a dead hippopotamus. They aren’t African anymore; they are Colombian, born and bred here for over 30 years.”
The hippos are a problem because every night they leave the water, eat enormous quantities of vegetation, return to the water, and shit. African rivers developed with this as part of the ecosystem; Colombian rivers did not. Lakes containing hippos now show altered oxygen cycles, additional terrestrial carbon, and phytoplankton communities more heavily dominated by cyanobacteria. The animals also erode riverbanks and compete for habitat with manatees, otters, capybaras, and river turtles.
Colombia has spent years attempting to solve the problem without killing the hippos. Fences did not work, neither did contraceptive darts since the hippos are too big and needed repeat doses. “Fixing” the hippos with surgical castration is more difficult than it sounds (and it already sounds difficult) because a male hippo’s testicles can retract forty centimeters into its body.
In one castration attempt, a military helicopter carrying an anesthetized hippo nearly overheated under its weight.
Officials tried finding foreign zoos willing to take them, but anyone equipped to own a hippo tends to already have the desired number of hippos. “Most zoos that want a hippo have one already,” an ecologist told Smithsonian. No transfer of hippos to zoos has actually happened.
As for killing them, that also created a different huge problem:
By 2008, the population had reached about two dozen, and Colombia’s ministry of the environment decided it was time to act. Echeverri López, who had recently graduated from the University of Antioquia in Medellín with a botany degree, was hired to help search for solutions. One of his first initiatives was to seek advice from wildlife experts in South Africa, who visited Doradal to investigate. “They told me: ‘You have a problem,’” Echeverri López said, as we sat in a restaurant in Doradal, a lively tourist town four hours east of Medellín. “They said: ‘The only solution is to kill them.’”
The next year, the government hired a hunter to begin culling the hippos, but when a photograph circulated in the media showing the corpse of a male called Pepe, who had wandered 60 miles from Escobar’s hacienda, pro-hippo protests erupted across Colombia. Echeverri López found himself puzzled by the response. “I was saying to myself: ‘Think about how many people are murdered in Colombia every day.’” This was a time when the ongoing civil war was still claiming the lives of more than 1,000 civilians a year. “And then there’s this outpouring of sentiment to protect the hippo. I couldn’t explain it.” In the face of public outrage, the minister of the environment resigned, and hippo killings were put on hold.
And so the hippos are sort of just there now.