Colombian Environment Minister Susana Muhamad has raised concerns among researchers that she is protecting rather than reducing a growing population of invasive hippos that threaten the country’s natural ecosystems and biodiversity. Although she didn’t directly mention hippos – a controversial issue in Colombia – Muhamad said during a speech in late January that his department would create policies that put animal welfare first, including the creation of a new Animal Welfare Division.
The hippos escaped from the property of drug cartel boss Pablo Escobar after his death in 1993. Left alone, the male and three females that Escobar had illegally imported from a US zoo settled in the Magdalena river in Colombia and some small nearby lakes – part of the country. main watershed. After years of breeding, the “cocaine-addicted hippos” have multiplied to about 150 individuals, scientists estimate.
Since hippos (hippopotamus amphibius) — considered the largest invasive animal in the world — have no natural predators in Colombia and mate at a steady rate, their population could reach 1,500 in 16 years, according to a modeling study published in 2021.” I don’t understand what the government is waiting for to act,” says Nataly Castelblanco Martínez, a Colombian conservation biologist at the Autonomous University of Quintana Roo in Chetumal, Mexico, and co-author of the study. “If we do nothing, in 20 years the problem will not have a solution.”
The researchers called for a strict management plan that would eventually reduce the wild population to zero, by combining the culling of some animals and the capture of others, then relocating them to facilities such as zoos. But the topic of what to do with hippos has polarized the country, with some seduced by the animals’ charisma and value as a tourist attraction and others concerned about the threat they pose to the environment and people. local fishing communities.
“A little surreal”
Several studies and observations suggest how destructive it could be to allow the Colombian hippo population to explode. A 2019 paper, for example, showed that compared to lakes without hippos, those where the animals have taken up residence contain more nutrients and organic matter that support the growth of cyanobacteria – aquatic microbes associated with blooms of toxic algae. These blooms can reduce water quality and cause mass fish kills, affecting local fishing communities.
other scientists predicted that hippos could displace endangered species native to the Magdalena River, such as the West Indian manatee (Trichechus manatus manatus), surpassing them for food and space. They warn that traffic accidents and attacks on people caused by hippos will become more frequent. And they warn that wildlife traffickers are already taking advantage of the situation illegally selling baby hippos – a trend that could intensify.
“It’s a bit surreal,” says Jorge Moreno Bernal, a vertebrate paleontologist at the University of the North in Barranquilla, Colombia. “This is just a taste of what could happen.”
When authorities in Colombia first recognized the rate at which the hippo population was growing, in the 2000s, they acted to reduce their numbers. But in 2009, when photos emerged online after soldiers shot and killed Escobar’s runaway male hippo, Pepe, outcry from animal rights activists and others plunged the Department of the Environment into an “institutional paralysis”, explains Sebastián Restrepo Calle, ecologist at the Javeriana University of Bogota.
Researchers say hippos don’t belong in Colombia – they’re native to sub-Saharan Africa. Simulations carried out by Castelblanco Martínez and his colleagues suggest that to reduce the population to zero by 2033, around 30 hippos would have to be removed from the wild population each year. No other course of action, including sterilization or castration, would eradicate them, according to the modeling of various management scenarios, explains Castelblanco Martínez.
The cost of inaction
The concern now is that instead of basing its decisions on evidence and conservation expertise, the government is listening to popular opinion, says Restrepo Calle. Neither Muhamad nor representatives of the environment ministry responded to Nature‘s requests for comments.
“Why prioritize a species over our own ecosystems? — especially a species that isn’t native, asks Alejandra Echeverri, a Colombian conservation scientist at Stanford University in California. Along with his colleagues, Echeverri published a study last month showing that Colombia has few policies governing invasive species compared to its total number of biodiversity policies.
Animal rights activists, meanwhile, say they are not ignoring environmental concerns. Luis Domingo Gómez Maldonado, animal rights activist and animal rights specialist at Saint Thomas University in Bogotá, says, “It’s not about saving hippos on a whim,” but rather solving the problem while doing justice to the hippos. “My unquestionable position is: let’s save as many people as possible, let’s do it in an ethical way.”
Researchers, too, say they have the best interests of the animals at heart. “Even if [advocates] don’t see it, we care about hippos,” says Castelblanco Martínez. “The more time passes, the more hippos will have to be killed, castrated or captured.”
The question is whether environmental authorities will move quickly to develop and enforce a management plan that is both ethical and effective. If they dwell on the issue for too long, Castelblanco Martínez warns, rural communities most affected by hippos could take matters into their own hands.
If the government doesn’t eliminate them, she says, people will use shotguns to do it.
This article is reproduced with permission and has been first post on March 2, 2023.