In and around the warm, tropical waters of the Rio Magdalena River, Colombia, an estimated 100 feral hippopotamuses can be found: swimming, grazing, and thriving. Fondly nicknamed the ‘Cocaine Hippos’, these gigantic mammals are perhaps one of the strangest aspects of Pablo Escobar’s legacy.
And much like Escobar himself, these creatures have grown to be quite well-known.
A recent Biological Conservation study, which has highlighted an urgent need to minimize the hippos’ population, has reignited a decades-long, ethically driven debate around the killing of the animals. This family began as a small group of 4 living in a private zoo on Escobar’s estate, Hacienda Nápoles, in the late 1980s. After the drug lord was killed in 1993, his estate – and all the exotic wildlife that resided there – was seized by the Colombian government.
The hippos, however, were deemed much too dangerous and difficult to move.
Left to their own devices and thousands of miles from their native home in Africa, this invasive species reproduced at a swift rate, quickly spreading out across the Magdalena River and making themselves at home. Nowadays, their numbers are estimated to lie somewhere between 70 and 110, a far-cry from the small group imported there almost forty years ago.
Contention has surrounded the issue of dealing with the hippos and their increasing numbers ever since they began reproducing. Scientists involved with this recent study have warned that a culling of a proportion must take place if the numbers are to be brought down effectively. As expected, they’ve received an extremely mixed response.
The reason for this response is easy to understand. On the one hand, the hippos’ destructive and potentially harmful nature, alongside the suspected risk they pose to the environment, suggests that their numbers must be controlled. However, this has mostly proven to be an unpopular recommendation in the past. As hippo numbers continue to decline elsewhere, animal activists have fought against any attempts to cull the Colombian bunch, ultimately arguing there isn’t enough evidence of a negative impact on the environment. Equally, members of the Colombian public have challenged any killing of the hippos. Not only are they for their touristic appeal, but there seems to be a genuine emotional attachment to the mammals across the country. In fact, culling attempts have often led to a public outcry. For example, when a male hippo (named ‘Pepe’) was found to be attacking humans and killing cattle in 2009, the local authorities arranged for it to be killed. Yet when a photo of Pepe’s dead body became public, controversy ensued, and the Colombian government was forced to cease all further plans of culling the animals. This, among other examples of public outrage, meant that the strategy for controlling the hippos has since centered solely on castration and relocation.
Furthermore, the science that surrounds the hippos is arguably more complicated than one might assume for an ‘invasive’ species. A study published last year (which questioned the supposedly ‘harmful’ nature of invasive species) concluded that animals such as the introduced hippos could potentially even help their new environments. A group of researchers – hailing from eight different universities and research centers worldwide – showed how the hippos similarities with extinct species found in Colombia thousands of years ago could mean they’d be able to restore ecological functions not seen since the Late Pleistocene era. Lead author of the study and PhD student at the University of Technology Sydney, Erick Lundgren, said the study was a ‘culmination of a decade of questioning invasion biology’s premise.’
Despite all of this, the authors of the Biological Conservation study are certain that action must be taken. And it must be taken soon.
For one thing, they’ve highlighted that castration and relocation strategies have proven to be ineffective in stopping the hippos’ population growth, warning that it could expand to a whopping 1400 by 2034. Co-author Jorge Moreno-Bernal explained that the study has indicated, first and foremost, that these strategies alone “will not be enough to eradicate the introduced hippo population.” At their current rate of reproduction, at least 30 individual hippos would need to be removed each year, which is “more than any castration/relocation strategies have achieved during the last 11 years.”
Unlike the sub-Saharan deserts upon which they usually roam, the hippos have no natural predators in Colombia, meaning they’re free to graze as they please. Furthermore, thanks to the gentler environmental conditions in the Magdalena River basin, the collection of hippos there have a higher reproductive rate and decreased mortality. Unless stopped, their family will continue to grow.
Therefore, the study has made it evident that more must be done if Colombia wishes to curb the hippos’ numbers. Whilst there are no suggestions to wipe out the entire population, it has been highlighted that culling must be incorporated into the control strategy if the hippos’ numbers are to be brought down effectively.
How soon must this be done, though? Are the hippos truly causing that much of a problem?
Moreno-Bernal warns that their impact can already be seen, with the hippos showing “evidence of a negative effect on ciénaga’s water quality, invertebrates and microorganisms” alongside a long history of them “causing damages to rural livelihoods.” The threat they pose to their human neighbors isn’t negligent, either. The first serious attack was documented in May 2020, when a rural worker was bitten, leading to several severe injuries. Finally, the cost of maintaining their current numbers would be far greater than any of the conservation efforts of Colombia’s native species – species such as the capybara and manatee, whom the hippos are successfully competing with for food.
It remains a nuanced debate, and it’s clear to see why it’s been difficult for the Colombian government to balance both scientific and ethical discourse with the public’s attachment to the animals. Ultimately, it appears that whilst a decision must be made soon, whichever option is chosen will be subject to criticism. For the time being, the hippos will continue to prosper.
For Times Media Mexico
Erin Sharrocks in London
