The Colombian government has begun sterilizing dozens of hippos originally introduced to Colombia by notorious cartel kingpin Pablo Escobar.
Colombia’s Regional Autonomous Corporation of the Negro and Nare Rivers (Cornare), an environmental agency, announced the sterilizations of 24 of the more than 80 hippos residing in the rivers near Escobar’s former Hacienda Napoles compound last week. Three decades ago, Escobar, then the leader of the infamous Medellin cartel, illegally imported the hippos for his private zoo, along with lions, giraffes, and a number of other exotic animals and birds
The move comes as the country’s hippo population continues to explode, with some estimating that there could be more than 1,400 hippos by 2039. Over the past year, researchers have argued that without intervention the invasive hippos pose a significant threat to the surrounding ecosystem.
In a widely publicized paper, a group of biologists called for the hippos to be culled, pointing out that the hippos “have significant effects on geomorphology, hydrology, and connectivity by wallowing, scouring, and compressing the bottom of water bodies [...] which can be critical for migratory species.”
“For me what is necessary here is to protect and preserve the integrity of our ecosystem over an exotic species,” Nataly Castelblanco-Martínez, one of the co-authors of the study, told VICE News in June, “even if this exotic species is super charismatic and super cute.”
Cornare said the sterilizations came with the help of the United States government, which donated 55 doses of GonaCon, an immunocontraceptive vaccine used in wildlife management.
“During a week, the professionals were in the town of Puerto Triunfo (Antioquia) to carry out what is expected to be a worldwide referent for the control of invading hippos’ population, which is a unique case in the whole world,” Cornare wrote in their press release. “Two strategies were implemented to medicate hippos. On the one hand, the medications are applied via darts to individuals that are fed and captured every day in a specially designed corral; and on the other hand, directly in the lakes, using dart rifles.”
While sterilizing the hippos is a far more palatable solution than culling them, Cornare conceded that it is not a “definite solution” but would “help to keep the population stable.” Yet, if successful, it said that the case could become a model for similar efforts to deal with invasive species elsewhere in the world.
Cornare did not immediately respond to Motherboard’s request for comment.