Colombia has begun a new campaign to sterilize its invasive hippos, showing signs that it is taking seriously the threat the animals pose to the country’s biodiversity and local communities. The plan is to initially capture, anesthetize and sterilize 20 hippos by the end of 2023 as part of a three-pronged approach the government is taking to reduce the rapidly growing population that has established itself along the country’s Magdalena River.
The other aspects involve sending hippos abroad to sanctuaries and zoos and, more controversially, euthanizing some of the animals. Colombia’s Environment Minister Susana Muhamad announced the plan at a press conference on November 2.
At the beginning of this year, Investigators feared that Muhamad would not take necessary action. to curb the hippo population after he met with animal rights groups, created a new animal protection division within the ministry and delayed the publication of a government-commissioned study on hippos. Although some still have concerns, they are glad the ministry is taking action.
“There are questions about how all of this will be carried out, particularly euthanasia, but it seems that the government in general is going in the right direction,” says Jorge Moreno-Bernal, a biologist at the Universidad del Norte in Barranquilla, Colombia. .
“We are in a race against time in terms of permanent impacts on the environment and ecosystem,” Muhamad said at the press conference.
Survive and prosper
Colombia’s hippos, considered the world’s largest invasive animals, thrived in the countryside after escaping from the farm of drug kingpin Pablo Escobar. Escobar illegally imported four hippos (hippopotamus amphibian) in the 1980s. Left alone after his death in 1993, the male and three females bred rapidly thanks to a lack of drought and predators, factors that normally keep hippo populations in check in their sub-Saharan Africa. native.
TO study commissioned by the Ministry of the Environment of Colombia and published in April It is estimated that there are now between 181 and 215 hippos in the country.. A population growth model estimated that, by 2050, there could be more than 1,000 if measures are not taken to control them.
Environmentalists are concerned that these highly territorial animals, which can weigh up to 3 tons, are altering the composition of Colombia’s main river with their excrement and are outcompeting other species, such as the capybara (hydrochoerus hydrochaeris), for habitat and resources.
Following the publication of the study in April, which detailed evidence of damage caused by hippos and recommended solutions, the government decided to take action, Muhamad said.
“One of the key conclusions is that there is no single strategy to control the hippo population and its environmental impact,” Muhamad said. Nature.
Three point plan
The first step is the sterilization campaign, for which the government has allocated 808 million pesos (200,000 dollars) this year. Each surgical castration will require a team of eight people (including veterinarians, technicians and support staff) for six to eight hours. Three sterilizations have been completed so far, according to David Echevveri, head of biodiversity management, protected areas and ecosystem services at Cornare, the regional environmental authority in charge of the campaign. In the coming years, the goal is to sterilize 40 hippos a year.
Researchers have noted that this will be a slow and expensive effort. “Sterilization is only a prerequisite for the other strategies. They must execute all three simultaneously,” says Rafael Moreno, an ecologist who participated in the hippopotamus study commissioned by the ministry while at the Alexander von Humboldt Biological Resources Research Institute in Bogotá.
Muhammad said Nature that a more effective strategy would be to export the animals. During the news conference, he said the ministry received a “concrete” offer from a buyer in India willing to accept 60 animals and that Indian environmental authorities are considering it.
The researchers who spoke with Nature They are skeptical about the export plan because they believe it could be expensive and logistically challenging. According to Ernesto Zazueta, owner of the Ostok Sanctuary in northern Mexico, who has expressed interest in taking some of the animals, exporting 60 hippos to India and another 10 to Mexico would cost a total of about $3.5 million.
The Colombian government will cover the costs of sterilization, and probably the costs of euthanasia, but the export will be paid for by the zoos or sanctuaries that import the hippos, Muhamad said. Nature.
Although the researchers Nature People we spoke to are glad that the government is moving forward with its plan to control the hippo population, but worry that it is relying too much on sterilization, because fewer details have been offered about the other two, more effective strategies. After sterilization, the ideal would be to confine the animals or export them, says Moreno. Returning them to the countryside to roam would allow them to continue inflicting damage on the environment, she says. In the past, sterilization efforts have not been effective because hippos reproduced faster than they could be trapped and operated on.
Moreno is also concerned about the ministry’s announcement that it will consult citizen groups about the hippopotamus euthanasia process. “It’s a technical issue that should be addressed by experienced professionals,” he says.
Environmentalists say they will have to be culled. But that part of the initiative will likely face legal challenges, says Elliot Doornbos, senior lecturer in criminology at Nottingham Trent University, UK. A public outcry occurred after a photo of a dead hippopotamus was shared online in 2009 and caused efforts to control the population to halt.
Muhammad said Nature that the Ministry of the Environment is working with experts to develop an “ethical euthanasia protocol” that will be “consulted in different committees of experts to guarantee its efficiency and rigor.”
“Depending on how many we export and how many we can sterilize, we will see how many we will have to sacrifice,” he added.
This article is reproduced with permission and was first published on November 10, 2023.