An outbreak of African swine fever (ASF) in Barcelona has put the Spanish pork sector on alert, the first of its kind in the country and one of the mainstays of the European meat industry. To date, five outbreaks have been detected and 91 sites affectedWhich prompted the government to implement “temporary emergency measures” that include banning the export of pigs and their products from the affected areas until February 2026.
The outbreak affects not only farms, but also particularly wildlife: the Ministry of Agriculture has confirmed that four of the 50 wild boars found dead in Cerdanyola del Valles have died of African swine fever. This brings the total number of these animals that died due to the disease in the region to 13.
the The mortality rate of this virus in wild pigs and domestic pigs is very high, almost 100%. in confirmed cases, raising concern about its spread.
The government, animal health experts and ranchers warn of a growing wild boar overpopulation — more than a million specimens in three decades — but Jaume Grau, spokesman for Ecologists in Action, points out that the current situation must be evaluated in a historical context.
“Deforestation in the late 19th and early 20th centuries, with the aim of converting all arable land to agriculture, contributed to the disappearance of forest ecosystems. In addition, hunting for human consumption also caused the disappearance of wild boars in many places,” Grau explains to 20 minutes. “In the last 40 years, without a doubt, the population has increased a lot, but if we talk about 80 or 100 years ago, we are probably the same or even less.”
The wolf and its crucial role in controlling wild boar
Grau recognizes that “there are problems or nuisances caused by these wild animals, which we have to see how we manage,” but he remembers that the wild boar plays an essential role in the ecosystems in which it lives, acting as a true “landscape architect.” “They scatter seeds, oxygenate the soil when they dig it for worms, and reduce the number of carcasses of other animals because they are also scavengers, so He explains that this reduces the risk of diseases transmitted through animal remains.
In addition, wild boar are an essential part of the food chain as prey for natural predators. He is Here comes the role of the wolf in the ecological balance of this species. “In regions such as the Levant and Catalonia, it was eliminated at the end of the nineteenth century and the beginning of the twentieth century,” Jaume recalls, so its return today “is excellent news, because it allows us to restore the natural relationship between predator and prey.”
But their job goes beyond hunting wild boar. “Even if there are a million wild boars, a wolf cannot eat them all,” explains Jaume, who points out that the really decisive factor is the so-called “fear environment” effect: “Wild boars detect the wolf by smell and scent.” They modify their behavior to avoid open areas — crops, grasslands or urban areas — where they are most vulnerable, they move toward forested areas with more shelter.
The expert emphasizes that this “environment of fear” naturally reduces the damage caused by wild boars to agriculture and urban environments. “Even if there are very few wolves, even if there is only one wolf in an area, “Their presence is enough for wild boars to avoid the areas where they have the greatest impact.” He explains.
That is why it is considered so The wolf is a “tremendous ally of farmers” and its presence as a tool for self-regulation should be encouraged Environmental protection against wild boar and other ungulates. “The only viable way to maintain balance in their populations is this natural self-organization, which combines direct predation with wolf-induced behavioral changes,” he concludes.
Could wild boar become extinct due to African swine fever?
After decades of wild boar population growth, and as the return of wolves begins to restore certain ecological balances, the outbreak of African swine fever is opening debate about the true vulnerability of this species. Although its ability to adapt is enormous, the extremely high mortality rate due to the virus poses an unprecedented scenario: “At the local level, in a municipality or in a particular population group, Mortality may reach 100%.”Jaume Grau warns.
However, experiences in countries where African swine fever is endemic – Eastern Europe, the Baltic states, Romania, or Bulgaria – show that this type is not disappearing. “Fortunately, we know that wild boars are not extinct,” Jaume says. “We don’t have any species left, and we have lost a lot of them.” He explains that what is happening is a pattern of population fluctuations: “Certain populations disappear and the disease remains less active while only corpses remain. “In other populations that have not been infected, wild boars can reproduce until a new outbreak arises.”
The animal’s behavior itself contributes to this dynamic. Unlike the wolf, which can travel tens of kilometers per day, the wild boar is very sedentary. “If he has food and shelter, he moves very little. He does not need to travel far,” the expert explains. Its voracious diet and adaptability allow populations to remain stable in specific areas. Which means that African swine fever outbreaks tend to remain “highly localized”.. Therefore, long-distance spread of the virus is not common without human intervention.
Precisely for this reason, authorities insist on avoiding practices that could unintentionally spread the disease. “When an infected wild boar is chased – by dogs or by hunting – it can escape its territory and carry the disease with it,” Jaume warns. In this sense, It is estimated that departments are acting cautiously Avoid traditional fishing methods that may help spread the virus.
What consequences might the disappearance of a wild boar have?
The eventual absence of wild boars, although striking because of the ecological weight of the species, will not cause an immediate collapse of the forest. “Forest ecosystems do not function at the same pace as animals,” explains Jaume Grau. for him Slow dynamics allow them to absorb sudden changes for several months or even a few years without becoming unbalanced Hardly. So, although an outbreak of African swine fever could temporarily empty the area, “they will come back, because there is habitat and food,” the expert recalls.
“Trees can grow better when there are wild boars.”
In the short term, the disappearance of wild boars would reduce functions that go unnoticed today: soil aeration, seed dispersal, or the natural clearing of the forest. “Trees can grow better when there are wild boars,” Grau admits, although he explains that their absence for a limited period will not have a serious impact. Shrubs and herbaceous plants will also lose the fertilizing contribution of their feces, however They are plants adapted to drought, fires and other disturbances that are able to withstand years without that contribution.
The real question arises in the long term, primarily when environmental pressures accumulate. “There are always many factors in ecology,” Grau recalls. With Catalonia experiencing periods of severe drought and an increasingly volatile climate, isolating the impact of the disappearance of a single species is “almost impossible”. If droughts, floods or other drastic changes are added to a shock such as African swine fever, the consequences could be exacerbated. “But today there is no way to know for sure,” Grau admits.
In fact, science doesn’t have strong precedents for predicting scenarios either. The researcher admits: “In the past 50 years we have not had areas where wild boars have disappeared, nor do we have much experience in seeing their tracks.” The lack of specific literature turns any prediction into guesswork. The only thing that is clear is that if the wild boar disappears completely for years – which experts consider unlikely – Forests can persist, although the cumulative effect of other factors can change Completely environmental equation.