Escobar's hippos sterilised

To curb their uncontrolled breeding, animal welfare organisations have sterilised 24 hippos.

GonaCon instead of killing

The authorities in Colombia have sterilised 24 hippos on the former farm of the late drug baron Pablo Escobar.

The Wild animals had bred uncontrollably, the environmental organisation Cornare explained. Escobar had kept two hippos along with other exotic animals such as giraffes, zebras and kangaroos on the farm. After his death, all the animals were sold – except for the hippos. They multiplied into a herd of 80 animals.

Cornare further reported that 24 hippos had been given a drug called GonaCon by means of darts. This is a contraceptive that works in both males and females. A further eleven hippos were sterilised in the conventional way.

Escobar's farm is now a tourist attraction

The probably largest hippo herd outside Africa had increasingly caused problems. «The presence of these animals in an ecosystem that is not their own has consequences such as the displacement of the local fauna.» The animals had also attacked fishermen on several occasions, explained Cornare employee David Echeverri.

After Escobar's death in 1993, there was a dispute over the ownership of his farm, located 400 kilometres north-west of the capital Bogotá. The private zoo «Hacienda Nápoles» was eventually opened as a tourist attraction.

Update 2026: From contraception to a kill plan

The sterilisations of 2021 did not stop the herd's growth. In 2022, the Colombian Ministry of the Environment placed the hippopotamus on the list of invasive species. Studies from 2022 and 2023 estimated around 170 to 215 animals; without intervention, there could be more than 1,000 by 2035. In early September 2024, the administrative court of Cundinamarca ruled in the first instance that the Ministry of the Environment must take measures within three months to eliminate the population in the Magdalena Medio, for example through sterilisation, fencing or killing.

On 13 April 2026, the Ministry of the Environment under Minister Irene Vélez approved a protocol under which around 80 animals were to be killed within the current year. The planned cost was 7.2 billion pesos, around 2 million dollars. The hippos were to be anaesthetised first and then put down; if that failed, they were to be shot. Implementation was delegated to the regional environmental authorities Cornare, Corantioquia, Corpoboyacá and CAS. The minister ruled out repatriation to Africa. Animal welfare organisations protested, and Senator Andrea Padilla called the decision 'cruel'. At the end of April 2026, Anant Ambani, son of the Indian billionaire Mukesh Ambani, offered to take in the 80 animals at his animal centre Vantara in Jamnagar. No response from the government is known.

The change of government in August 2026 brought a U-turn. In September 2026, the new Minister of the Environment, Fabio Arjona, presented an action plan that provides for private funders, further authorities and an app for sightings. He makes no mention of killings. Arjona had previously stated that lethal control was 'not a solution' in his view. According to the newspaper 'El Colombiano', the approved funds never reached Cornare. Reports of killings already carried out could not be found by mid-October 2026.

The case shows what contraception can and cannot achieve: it only works if it is deployed early and consistently. Those who wait for decades end up facing the question of mass killings. More on the beginnings of the programme in the article 'Pablo Escobar's hippos are to receive contraceptives', on non-lethal alternatives in a fact check, on the topic of deterring wild animals and on how the pet trade endangers biodiversity. Further articles in the category Wild animals.