Hundreds of ‘Cocaine Hippos’ Are Terrorizing Colombia. This Biologist Has Agreed to Help Track Them Down

Forrest Galante has bad luck with hippos. He was nearly killed twice by the animals while growing up as a kid in Zimbabwe. So it’s fair to say Galante was treading cautiously this winter as he explored a dense jungle island in the middle of Colombia’s Rio Magdalena, which is now home to a prolific and very problematic herd of hippopotamuses. 

Known the world over as “cocaine hippos,” these invasive giants are the descendants of Pablo Escobar’s pet hippo herd, which has grown from four to around 200 and spread well beyond Escobar’s estate in the time since the kingpin’s death in 1993. With no natural predators around and a massive river — the Magdalena — at their disposal, the amphibious mammals continue to thrive and expand in Colombia. (To be clear, these hippos are not addicted to cocaine. They’re called “cocaine hippos” because they were introduced there by the most famous cocaine dealer of all time.)

As an explorer, wildlife biologist, TV host, and conservationist, Galante has worked with dangerous animals all around the world. Over the past few years, he’s been coordinating with a Colombian government agency, Cornare, to try and solve the country’s cocaine hippo problem. He just returned from a months-long trip to Colombia, where he helped refine the government’s ongoing efforts to capture and sterilize the invasive critters. This is an urgent ecological problem, as the hippos are harming native species, wrecking waterways, and causing conflicts with people.

Although there are no published news reports available on the internet of hippos attacking humans in Colombia, it has certainly happened. Galante says he’s spoken with two people there who were attacked by hippos. One of them, a farmer, was getting water from the river when a hippo charged and trampled him, breaking his back and leaving him paralyzed. Scenarios like this one have played out countless times across sub-Saharan Africa, where hippos are considered the most dangerous large animal on the continent, killing roughly 500 people a year.

Hippos also degrade habitat by polluting and destroying waterways, and their presence in rivers and lakes threatens a number of native critters, including the critically endangered Magdalena turtle. And just like Florida’s Burmese pythons, there are more of them every year.

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“In the wild, hippo infant mortality rates are fifty to fifty nine percent … but according to one study, that goes down to fifteen percent in the second year, and four percent each year after,” Galante tells Outdoor Life. “So, if you compare that with a hundred percent survival rate, which is what we’re seeing in Colombia, this might sound melodramatic. But hippos will literally take over the country at some point. There is nothing to stop them.”

The most obvious solution, tracking and killing all the hippos, has proven controversial because locals have grown to love the big, “cute” animals they associate with Disney movies, Galante explains. The government-approved hunt for Pepe, one of Escobar’s original males, in 2009 was a PR nightmare. And although Galante says there are unconfirmed rumors that black-market hippo hunts are still taking place, the Colombian public will never support the regulated hunting or culling of the now world-famous hippos. 

So, in 2023, the Colombian government announced it was starting a highly ambitious (and costly) program to capture and sterilize Escobar’s hippos and their descendants. By late November, officials had caught and sterilized four of them — two adult females and two juvenile males — and set a goal for 40 sterilizations per year. As it turns out, though, castrating a full-grown hippopotamus is easier said than done.

“Like any large mammal, hippos learn pretty quickly and they’ll move to a new area,” Galante says of the various challenges Colombian wildlife managers now face. “These hippos are also spread out over [roughly] 500 square kilometers, and each water body has its own hippos, so you have to build new bomas [traps] in each location … and it gets expensive. This is a huge, multi-layered project.”

Another part of the government’s plan is to eventually relocate some of the hippos to a wildlife sanctuary in India — something Galante is helping coordinate as well. (Galante has also been filming part of the project for an upcoming television series on Discovery.) When he asked local experts where the majority of the problem hippos were, they ushered him to a densely vegetated island in the middle of the Rio Magdalena.

“We took a boat and went out there, and this was maybe the most dangerous situation I’ve ever been in with wildlife,” Galante says. “We were walking in this bush where you have less than 15 feet of visibility, it’s this tropical Amazonian jungle. So we came up along this game trail and, of course, we startled a hippo and it charged us.”

The hippo turned away at the last second, Galante says, and they had no further run-ins that day. But the one charge was enough to convince Galante that trapping the island’s hippos would require significantly more funding and manpower than they had at their disposal. The next best step, they figured, would be to focus on the lakes surrounding Hacienda Nápoles. (Escobar’s estate, where his exotic zoo was located, is now a theme park.)

After locating a few pods of hippos in the lakes, Galante and the Cornare team brought in a retrofitted corral that they baited with sugary foods like carrots, watermelons, and beets. He says it took about a week to catch the first baby hippos, which they sterilized with injections of GonaCon. Three weeks later, after keeping the corral-trap baited, they caught the mother hippo.

“When we caught that adult mother in our boma trap, she was with those same two babies, plus two other babies — one that was about a year old and one that was about two,” he explains. “So that’s four generations all in one boma.”

After treating the younger hippos with GonaCon, a veterinarian surgically sterilized the adult female. Unlike the male castrations, which are quick and straightforward  — “You just chop their nuts off and let them go,” Galante says — sterilizing females is much more complicated.

“He operated on her all night, and he uses this incredible methodology that I’ve never seen before. Instead of opening all their guts up, he makes these tiny incisions and does it all by feel … It’s incredible, and he needs to publish this methodology,” Galante explains. “He pulled out her ovaries, cauterized them, sewed her up, and let her go. Now, because it’s Colombia and it’s a billion degrees out, he had to start doing this at 10 p.m. and finish before the sun came up so she didn’t die of heat exhaustion.”

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Now that officials have seen some success, Galante says, the Colombian government will continue sterilizing as many hippos as they can safely catch. He says he doesn’t know the exact number of hippos that have been sterilized so far. But he knows he won’t be returning to that mid-river island anytime soon without reinforcements. 

“There’s no way you can deal with those hippos without bringing in a massive construction crew and clearcutting a large area. And then you’d need generators, and tractors, and flatbed boats, which could cost millions” Galante says. “We have not solved this problem, to be clear. What we did over the last few months is create a blueprint to solve the problem.”