The Colombian government is trying to figure out whether the animals of the former drug lord are a problem or a resource
The hippos that belonged to Pablo Escobar are today at the centre of a heated debate between scientists and environmentalists in Colombia. In fact, when the drug lord was killed, in 1993, the Colombian government took possession of his princely estate, in the north-west of the country, which included also a zoo: most of the animals present were relocated elsewhere, but not four hippopotamuses, which were left to move freely in the area. Now it is estimated that their number has reached a few dozen and it is debated whether they represent a potential risk to the ecosystem, or an advantage.
Over the years, the four hippos have moved along the banks of the Magdalena River, Colombia’s main waterway, and have reproduced. To calculate the exact number is impossible, but experts estimate that the population includes between 80 and 100 specimens, that it is growing exponentially and that “within a couple of decades, it could reach the thousand” (words of Jonathan Shurin, of the University of San Diego).
Why they are a problem
The hippopotamus is an African herbivorous mammal, so its presence in Colombia is not natural. This is what is worrying the Colombian authorities, because Escobar’s animals directly threaten endemic species such as otters and manatees, they modify the chemical composition of the river (they feed on the grass they find on the shore, but defecate in the water) and finally they alter the conformation of the wetlands creating water flow channels simply by moving their heavy bodies. Not to mention the potential risk to humans: hippos are very territorial and attack intruders with great violence.
What to do?
The solution to the problem is not easy: the killing of hippos is not seen favourably by environmentalists, who would prefer to resort to sterilization or relocation to new zoos. But these two hypotheses clash with the fact that the animals are very dangerous, precisely because they are territorial, aggressive and surprisingly quick, despite their size. Approaching them to sedate and castrate them is a dangerous, difficult and expensive activity. Adjectives that also apply to movement in zoos: net of the risks, it is estimated that about 4 thousand euros are needed for the relocation of each specimen.
But what if nothing is done?
Scientists are wondering what the real impact of hippos on the local ecosystem is. Their presence undoubtedly has consequences, nobody is arguing about that, but the question is how significant they are. A study, recently published in Ecology, shows that they are not at all dramatic.
Just taking advantage of these data, there are those who hypothesize that the presence of hippopotamuses can be positive. The nerve centre of the discussion is that these animals could replace the great herbivores that have become extinct in Colombia over the centuries.
So, yes, the chemical composition of the water changes, some fish could pay the price and so could otters and manatees. But all this could be accompanied by the creation of different river habitats (those inhabited by hippos and those that are not), with a consequent increase in biodiversity. Precisely for these reasons the Colombian Environmental Agency is monitoring the situation closely, using experts, in order to understand how to move in the medium-long term.