Story by insider@insider.com (Crystal Raypole)
- Authorities plan to relocate 70 of the hippos living wild in Colombia, but it's not an easy task.
- Since hippos are large, aggressive, and have very tough skin, sedation requires a team effort.
- Hippos that can't be moved will likely be sterilized or culled, since they threaten the ecosystem.
After the drug cartel leader died in 1993, most of the animals in his private menagerie were moved to new homes in zoos. But his four hippopotami — three females and one male — escaped to make their homes in Colombia's Magdalena River. There, they thrived and started to breed.
Today, roughly 140 hippos live in the area. Some scientists estimate their numbers could reach 1,500 by 2030 if no action is taken.
As hippos pose a major threat to both humans and the Colombian environment, this is a serious concern.
Before the hippos can be moved to new homes, they need to be trapped and anesthetized, for the safety of everyone involved. This task may sound terrifying, especially when you consider that hippos kill about 500 people in Africa each year — in fact, they're one of the deadliest land animals in the world.
So, how do you safely trap, sedate, and transport at least 70 of them?
Very carefully, according to David Echeverri López, head of Biodiversity Management, Protected Areas, and Ecosystem Services at Cornare in Colombia. Cornare is the government agency handling the hippo relocation.
"We hope to relocate some number of hippos this year," López, whose answers were translated from Spanish, told Insider. He emphasized, though, that not all of the hippos will move to new homes.
"At the moment we only have interested zoos in Mexico and India," he said. So, authorities will continue pursuing other options, from sterilization to searching for other zoos and sanctuaries willing to take hippos.
As for the relocation itself, Cornare plans to use their previously established capture protocol, which involves trapping the hippos in a corral.
López said they put food inside the corral, lock the hippos in, and a team of professionals anesthetizes them. From there, the hippos are put into a crate, driven to the airport in trucks, and flown to India or Mexico.
But this isn't an easy process. López said it requires the combined efforts of not just the Cornare team, but also the help of the zoo staff who will receive the hippos.
"Everything with hippos is risky, as well as complex, costly, and time-consuming," López said.
That's because it's incredibly difficult to catch, much less anesthetize, even one hippo.
Colombian veterinarian Gina Paola Serna told The Guardian in 2021 that anesthetizing hippos is very tricky, as it requires tranquilizer darts able to pierce their skin, which is 2 inches thick.
Serna also said the drugs required to anesthetize such large animals are incredibly expensive. Knocking out 70 hippos, then, may pose some financial difficulties for Colombian authorities in charge of the process, but López could not say exactly how much Cornare anticipates spending.
The thickness of a hippo's skin, and the density of their subcutaneous tissue, also makes it challenging to deliver enough anesthesia to keep them asleep for the right amount of time.
Hippos are native to Africa, where their natural predators include lions, hyenas, and crocodiles.
In Colombia, hippos have no predators, and the wet climate is more favorable for reproduction — so much so, in fact, that hippos begin reproducing at a younger age than they would in Africa, where regular droughts help keep the population in check.
Colombia ruled hippos a toxic invasive species in 2022, in part because they disrupt aquatic ecosystems and diminish the quality of the water. They also displace native wildlife and increase the pressure for resources, López said. For instance, they threaten river turtles, caymans, and the endangered Antillean manatee.
Not only do hippos take over river habitats; their waste also changes the quality of the water. Lakes with hippos contain more organic matter, which promotes the growth of bacteria and toxic algae that kill fish — a potentially disastrous consequence for the people and animals who eat those fish to survive.
And of course, hippos are huge, aggressive, and very strong.
"As a highly territorial species with wild and unpredictable behavior, they pose a danger to local communities, including traditional fisherman and others living near rivers, who may be killed by hippo attacks," López said.
To date, one person in Colombia has been seriously injured by a hippo, though none have died.
Environmental authorities have made efforts to medically sterilize some of the hippos with Gonacon, an immunocontraceptive vaccine.
Cornare has sterilized 13 hippos, López said, and relocated seven to zoos in Colombia.
Yet these solutions haven't done much to halt population growth. With few other options, the plan to relocate the animals came about as an alternative to killing them. The country will have to pursue other options for the hippos that remain after this proposed relocation.
Some biologists believe culling — killing a certain number of hippos each year — is the only real solution.
But after one hippo was killed in 2009, the resulting public protest led to legal protection for the remaining hippos — despite the fact they aren't native to Colombia and Escobar illegally imported the original four hippos in the first place.
López said culling hippos is the last possible option, but it can't be discarded, either.
"In the case that the animals cannot be captured, sterilized, or relocated, they cannot remain in freedom and reproduce, since the problem would have no end," he said.
