Image: Shurin Lab / UC San Diego

While many of us have probably read about Pablo Escobar’s hippos that escaped his zoo, it’s been unclear to biologists what sort of impact the hippos have had on Colombian ecosystems. There are currently 80-100 animals in the Magdalena River and researchers estimate that in 20-40 years there could be thousands.

As NatGeo explained, for over a decade the Colombian government has been pondering how to best curb the growing population, a strategy largely supported by conservation experts. But not everyone is on board. Without direct evidence that the animals are doing harm, some ecologists argue that there’s no reason to cull or relocate them. 

However now, UC San Diego biologist Jonathan Shurin who has been working with the Universidad Pedagógica y Tecnológica de Colombia has been measuring the hippos’ impact on their new realm and has some new insights to report. Mainly, that it’s complicated!

What’s The Plan: As the LA Times noted, at present, though, there is no strategy to keep this population in check. Colombian officials told Shurin there was no money to fund a sterilization campaign, and the locals are opposed to culling the herd.

Why This Matters: Smaller invasive species are generally viewed as disruptive (or even disastrous) to local ecosystems, but we’re still learning about the impacts that larger invasive species have on their new homes. In the case of Australia’s camels, their herds have been slated for culling by the government, but it’s hard to assess this decision as the Australian government has overestimated kangaroo populations to justify cruel “roo culls.” Humans have altered the distribution of nature so profoundly that it’s difficult to know what’s what. The best we can do is use data and science to help manage nature in a good-faith way.