When Gina Serna set out to control Pablo Escobar’s wild hippos, she didn’t count on the flood of tears.
“I was crying a lot,” said Serna, a Colombian veterinarian who is spearheading an ambitious campaign to sterilize the dozens of hippos that are roaming Colombia and causing devastating environmental damage.
“I am a strong woman, but it was a lot of stress because I love these animals and I want to protect them.”
The crying began almost as soon as Serna began filming “The Hunt for Escobar’s Hippos,” which premieres on the Smithsonian Channel on Wednesday at 8 p.m.
Her emotions may have had as much to do with the tense surgery she performed on a young hippo in the wild as it did with memories of her father, who was killed by the notorious drug lord in 1991.
It was Serna’s cattle rancher father who first took Serna, 43, to see the giant mammals, submerged in muddy waters in an artificial lake on Escobar’s sprawling estate.
As a little girl growing up near Medellin in the 1980s, Serna and her family would visit them at Hacienda Nápoles, where the notorious cocaine kingpin held lavish parties and bullfights. He also maintained a zoo full of exotic beasts.
“I was obsessed with those animals, and so my parents took me a few times,” said Serna in a Zoom interview from her home in Medellin last week. “The hippos were my favorite.”
They were also loved by Escobar, who eagerly showed them off. He got two of his hippos from the San Diego Zoo in the early 1980s and another two from the Ochoas, fellow members of the Medellin cartel who tried to compete with Escobar in their acquisition of exotic creatures, but gave them up when they couldn’t care for the animals.
Admission to Hacienda Nápoles was free to local residents, who came in droves, amazed by the sight of elephants, giraffes, zebras, kangaroos, rhinos and hippos, many of them smuggled into the country by the leader of the Medellin cartel.
“We knew he was a narcotrafficker, but that was normal in Colombia in those years,” said Serna, who grew up on her family’s cattle ranch nearby.
But after Escobar was gunned down by the Colombian military on a Medellin rooftop in December 1993, his property was seized by local authorities and most of the animals either died or were taken to zoos.
The hippos proved too cumbersome and costly to move — about $40,000, at a time when almost half the population of Colombia was living below the poverty line.
Nearly 30 years later, the hippos, which are found in the wild only in Africa, have multiplied in Colombia. “They have no natural predators in Colombia and they are breeding every year,” said Serna.
There are now 60 hippos roaming the region, and they are displacing local species of fish, turtles and manatees. They’ve also attacked ranchers and fishermen who live along the banks of the Rio Magdalena, the country’s biggest river at nearly 1,000 miles.
Serna, whose specialty is the conservation of cougars and jaguars, said she’s become a local expert on hippos — and can tell the males from the females, though their reproductive organs are inside their bodies. The biggest challenge is getting them to stay put, she said.
“They don’t stay in the lake at Hacienda Nápoles,” Serna said. “We have tracked groups that have traveled nine hours down the river from the hacienda.”
Serna describes the hippos as “mega herbivores” that spend up to 16 hours a day submerged in water, where their waste accumulates and saps the river’s oxygen, killing fish and other species.
The endangered Magdalena river turtle and manatees have been displaced from the region because of the hippos, who also erode grasslands where they forage.
“Because they are so heavy their weight compacts the earth and destroys plants,” said Serna. An adult male can weigh up to 9,000 pounds while an average female is 3,000 pounds.
And they can be dangerous to humans.
Two months ago, a hippo attacked a local farmer who accidentally hit it on the head with a bucket he’d dipped into the Magdalena, Serna said. The hippo chased the farmer and trampled him, breaking his arm.
The documentary captures a surgery Serna performed on a young female hippo her team christened Imbuvu. The team tracked her and her mother then lured the two into a fenced-off pen by sprinkling carrots — “our secret weapon” — on the ground, then shot them with tranquilizers.
Serna begins the surgery in the wild — a delicate and painstaking procedure that lasts for seven hours. One hippo requires more than $3,000 worth of anesthetic. “We don’t work with such big animals in Colombia and we have to import what we need from Africa,” she said.
It’s a Herculean effort, and so far she has managed to sterilize just four hippos. But culling the wandering herd in other ways is impossible; a Colombian court ruled that killing hippos is a criminal offense.
The ruling came after “Pepe,” a male hippo who escaped from Hacienda Nápoles in 2009 and terrorized local fishermen, was killed by the Colombian military, aided by two experienced big game hunters.
After photos emerged of the soldiers and hunters in camouflage standing behind Pepe’s remains, activists took to the streets wearing hippo masks to pressure the government to ban hippo hunts.
Serna knows what it’s like to be victimized by violence.
In February, 1991, members of the Medellin cartel set off a car bomb at the La Macarena bull fighting ring in Medellin just as her parents were leaving the venue. The target was a carload of National Police intelligence officers who were parked next to the building.
Twenty-two people died in the explosion, including nine police officers and Serna’s father.
Her story and her mission have prompted offers to help, though few have come forward to donate money or volunteer.
“I really wanted to show the world the problem of managing these hippos,” she told The Post. “I hope that people can see that what we are trying to do here is not very easy.”