Wild Boar Switzerland: Recreational hunting exacerbates the problem

Wild boar populations have been rising across Europe for decades, while recreational hunting has intensified in parallel. Yet it has not succeeded in reducing the population. This dossier shows why hunting logic leads to a dead end when it comes to wild boar and why recreational hunting itself is among the most important causes of the population explosion.

Profile

The wild boar (Sus scrofa) belongs to the family of true pigs (Suidae) and is the ancestor of the domestic pig. It is a highly social, intelligent and adaptable animal that lives in family groups. In Switzerland, the wild boar was almost extinct in the 19th century and only began spreading again in the 20th century. Today it mainly inhabits northwestern Switzerland, Zurich, Ticino and increasingly other parts of the country.

Biology and social behavior

Wild boar live in matriarchal family groups led by an experienced lead sow. The lead sow knows the best feeding and resting places, avoids danger sources and coordinates the behavior of the entire group. Male animals (boars) are driven out of the group as yearlings and thereafter mostly live as loners. Only during the mating season do older boars temporarily join a group.

The wild boar is an omnivore with a pronounced preference for acorns, beechnuts, insect larvae, roots and agricultural crops such as corn. It is predominantly nocturnal, a behavioral adaptation largely attributable to disturbance by recreational hunting.

Reproductive Biology

Wild boar are so-called r-strategists: they respond to favorable living conditions with a rapid increase in reproduction rate. In mast years (heavy acorn and beech mast), reproduction increases dramatically. A sow can become sexually mature from less than one year of age and produce four to eight piglets per litter, in exceptional cases up to twelve. Under natural conditions, meaning without the destruction of social structure by recreational hunting, typically only the lead sow of a sounder reproduces.

The Population Explosion: Causes and Misinterpretations

The Numbers

Wild boar hunting figures in Switzerland have increased almost two-hundredfold over the past 50 years. According to the Federal Statistical Office, more wild boar were shot nationwide in 2024 than ever before. Annual wildlife damage amounts to hundreds of thousands of francs per canton, mainly to corn, grassland and vineyards.

The Standard Explanation

The hobby hunting lobby explains the increasing populations with climate change and mild winters, more frequent mast years due to more beech and oak trees, the abundant food supply from agriculture, and the wild boar's natural adaptability.

All of this is true. But it lacks the crucial factor: the role of recreational hunting itself.

The Lead Sow Question: How Recreational Hunting Fuels Reproduction

Perhaps the most explosive scientific finding regarding wild boar dynamics concerns the function of the lead sow. In intact sounders, the lead sow regulates the reproduction of subordinate sows through pheromones and social hierarchy. When the lead sow is shot by recreational hunters, the sounder disintegrates, and all sows, including yearling sows, immediately become estrous and capable of reproduction.

This mechanism is now documented by numerous studies. Italian pheromone researcher Prof. Andrea Mazzatenta has shown that in the Abruzzi and Tuscany, doubling wild boar hunting led to a doubling of the population. A French long-term study by Sabrina Servanty and colleagues (Journal of Animal Ecology) compared reproduction over 22 years in a heavily hunted forest area in the Haute Marne department with a lightly hunted area in the Pyrenees. The result: Heavy hunting leads to significantly higher reproduction and stimulates fertility. In intensively hunted areas, sows become sexually mature earlier, are lighter at first pregnancy, and increasingly produce piglets outside natural farrowing seasons.

Bavarian wildlife expert Hohmann concludes after extensive literature research that the thesis of social reproductive suppression by lead sows is not tenable in the blanket form propagated by parts of the hunting community. At the same time, he makes clear: Shooting lead sows destabilizes the sounder in any case and leads to uncontrolled reproduction of young sows, exactly the effect that recreational hunting complains about.

More on this: Science: Hunting Activity Causes the Species to Multiply and Contraceptives for Wild Boar

The Baiting Problem

In many cantons and neighboring countries, attracting wild boar with feed (baiting) is a common hunting practice. While baiting allows targeted shooting, it is counterproductive: primarily individual approaching boars and yearlings are shot, not the reproductively relevant sows. The additional food supply eliminates natural winter mortality, boosts reproduction, and also affects other wildlife species like deer and badgers. Baiting is thus a prime example of how recreational hunting exacerbates the problem it purportedly solves.

The Damage Logic: Who Profits, Who Pays?

Wildlife Damage

Wild boar damage in agriculture is real and burdensome for affected farmers. Annual damage costs per canton often reach six-figure sums. The damage primarily affects corn fields, grassland, and vineyards. The question is not whether damage occurs, but whether recreational hunting is the right response to it.

What really works

The most effective measure against wild boar damage is electric fencing that is set up early and maintained. This method is proven and recommended by authorities. The disadvantage is large-scale fencing, which impairs the connectivity of wildlife habitats. In the long term, a stable, intact sounder system would help more than permanent hunting pressure: A sounder with an experienced lead sow avoids agricultural land more effectively than a destabilized, 'leaderless' group of young sows.

More on this: Dossier: Hunting and Animal Welfare and Dossier: Wildlife Corridors and Habitat Connectivity

Ethical dimension

Driven hunts: Terror and stress in the forest

Wild boar in Switzerland are frequently hunted in driven hunts with dogs. Entire forest areas are thrown into turmoil for hours. Beaters and dogs flush animals from their resting places, whereupon they are driven past lines of hunters. The accuracy rate for fleeing wild boar is low, as are follow-up search rates. For the animals, driven hunts mean extreme stress, not only for wild boar, but for all forest inhabitants.

Piglet hunting

In some cantons, piglets may be hunted with shot. The shooting of animals only a few months old is declared as population regulation, but is ethically highly questionable. Piglets that lose their mother die in many cases.

Night hunting and constant disturbance

Since wild boar are predominantly nocturnal, a large part of hunting takes place in darkness, with night vision devices, spotlights and thermal imaging cameras. This constant disturbance drives the animals into increasingly remote areas and increases pressure on remaining refuges.

The vicious circle of recreational hunting

The dynamics with wild boar can be summarized as a vicious circle: Recreational hunters shoot lead sows and boars. The sounder structure collapses, young sows become pregnant immediately. The reproduction rate increases, the population grows. Wildlife damage increases, calls for more recreational hunting become louder. More recreational hunting further destabilizes the sounders. And so on.

This mechanism, compensatory reproduction under hunting pressure, is particularly pronounced in wild boar because as an r-strategist it is evolutionarily programmed to respond to increased mortality with maximum reproduction. The more that are shot, the more wild boar there are. The shooting figures of the last 50 years are the proof.

More on this: Studies on the impact of recreational hunting on wildlife

What would need to change

Protection of lead sows: The lead sow is the central regulatory instance of a wild boar sounder. Shooting her destabilizes the social structure and leads to all sows in the sounder, including yearling sows, becoming pregnant immediately. A ban on shooting lead sows would be the most effective single measure for reducing the reproduction rate.
Ban on baiting: Baiting eliminates natural winter mortality, boosts reproduction and leads to mainly non-reproduction-relevant animals (boars, yearlings) being killed. Baiting is counterproductive and must be banned.
Prioritization of prevention measures: Electric fences, adapted crop rotations and spatial separation of agricultural land and wildlife habitats are more effective than intensifying recreational hunting. The cost calculation favors prevention, not shooting.
Large-scale quiet zones: In undisturbed areas, stable sounder structures form where the lead sow naturally regulates reproduction. The permanent continuous disturbance by recreational hunting prevents precisely this stabilization.
Professional Wildlife Management: Wild boar regulation must be transferred to professional wildlife wardens who intervene specifically, in a planned manner and with expertise, without further driving the cycle of disturbance, sounder breakdown and compensatory reproduction.

Arguments

«Without intensive hunting, wild boar populations would explode completely.» Shooting figures have increased almost two hundredfold in 50 years, yet populations continue to rise. Population ecology shows: intensive hunting destroys sounder structures, triggers compensatory reproduction and rejuvenates the population. Recreational hunting creates the problem it claims to solve.

«Wildlife damage proves that more shooting is necessary.» Wildlife damage is real, but recreational hunting is not the answer. Electric fences are demonstrably more effective than shooting. Intact sounders with experienced lead sows avoid cultivated land more deliberately than destabilized groups of young sows. More recreational hunting leads to more damage, not less.

«Lead sow shooting is a myth – social reproductive suppression is not scientifically proven.» The long-term study by Servanty et al. (Journal of Animal Ecology) over 22 years clearly shows: intensive hunting leads to higher fertility and earlier sexual maturity. Mazzatenta has proven in Italy that doubling recreational hunting led to doubling of the population. Even Hohmann, who criticizes the general lead sow thesis, confirms: lead sow shooting destabilizes the sounder and leads to uncontrolled reproduction.

«Wild boar are nocturnal – night hunting is therefore necessary.» The nocturnal activity of wild boar is significantly an adaptation to disturbance by recreational hunting. Studies show that wild boar in undisturbed areas are also active during the day. Night hunting combats a symptom that recreational hunting itself causes.

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Our Standards

The wild boar is not a pest. It is a highly intelligent, socially living wild animal that has belonged to Europe's forests for millennia. The fact that populations are rising despite massive hunting pressure is not an argument for more recreational hunting, but striking proof that recreational hunting is the wrong tool. Population ecology shows: Intensive hunting destroys sounder structures, triggers compensatory reproduction and rejuvenates the population. Those who want to reduce wildlife damage must protect lead sows, ban baiting and prioritize prevention. A system change toward professional wildlife management is not radicalism, but an adaptation to the current state of science. This dossier is continuously updated when new data, studies or political developments require it.

More on recreational hunting: In our Hunting Dossier we compile fact-checks, analyses and background reports.