How does recreational hunting stress wild animals?

Chronic stress, destroyed social structures and altered use of space are scientifically documented consequences of hunting.

Current research shows what happens in the body of a hunted animal and what this means for wild animals and their populations.

What happens in the body of a hunted animal?

When a wild animal perceives a threat, be it the scent of a human, the sound of a gunshot or barking hunting dogs, its nervous system activates the so-called “fight-or-flight” response within milliseconds. The adrenal glands release adrenaline and the stress hormone cortisol. Heart rate and breathing rate rise, blood is diverted to the muscles, and non-essential functions are throttled back.

This reaction makes evolutionary sense: it increases the chance of survival in real danger. The problem arises when it becomes chronic. Permanently elevated stress hormones can weaken the immune system, impair reproduction and inhibit growth. The animal then lives in a state of constant alert that wears its body down.

Measurements confirm this. Santos et al. (2018) showed in red deer in south-western Europe that hunting management factors shaped stress hormone levels more strongly than environmental conditions and individual characteristics. Kelava Ugarković et al. (2025) measured an average of 431 nmol/l cortisol in 407 wild boars killed after drive hunts, compared with 119 nmol/l after single hunting from a high seat. In wolves from heavily hunted areas of Canada, Bryan et al. (2015) found markedly higher stress hormone levels in hair samples than in less hunted animals. The pattern is consistent: hunting pressure increases stress. All studies, with links to the original papers, can be found on our studies page at Effect 1: Animals under permanent stress.

Acute versus chronic stress: a crucial difference

It is scientifically important to distinguish between acute and chronic stress. Acute stress, a sudden fright or a brief flight, is biologically normal and leaves hardly any lasting damage. Chronic stress, by contrast, is a permanent state. In hunted areas, disturbing events recur over months: the high hunt in September, the small-game hunt in autumn, the driven hunts in December. In between come dog training, patrols of the hunting ground and shooting practice.

For many wild animals there is hardly any hunting-free period of rest. The rock ptarmigan shows how directly the hunting season takes effect: in hunted areas, its flight distances rose markedly during the hunting season and only fell back to baseline afterwards, while in hunting-free areas they remained constant (Sooth et al. 2026). How long elevated stress hormones persist after the hunting season has not been studied for Switzerland. Given the high hunting intensity and the closely spaced pattern of hunting, however, recovery phases are likely to be short in many places.

Behavioural changes: nocturnal activity, withdrawal, avoidance behaviour

The response to hunting pressure shows up not only hormonally but also in measurable changes in behaviour. GPS radio collaring and camera traps have documented several typical patterns:

• Nocturnal activity: Under human influence, wild animals shift their activity to the night. A meta-analysis of 76 studies found this effect across continents, habitats and species (Gaynor et al. 2018, Science). During the day the animals stay in cover, a classic anti-predation strategy that also applies to recreational hunters.
• Retreat into cover: In Berchtesgaden National Park, female red deer in the hunting zone chose closed forest far more often than in the hunting-free zone (Eggers et al. 2026). This retreat costs energy, particularly in the food-scarce autumn and winter period.
• Avoidance of open land: In hunted regions, wild animals avoid open areas such as meadows and fields, which would actually be good food sources. This can increase browsing damage in the forest, which in turn serves as an argument for more hunting.
• Hunting-ban areas as refuges: In the Central Alps, 243 radio-collared red deer were largely able to choose their habitat independently of human influence wherever networks of hunting-ban areas exist (Rempfler et al. 2025).

This is well documented for Grisons: around half of the red deer killed in Grisons are shot in the vicinity of the hunting-ban areas (Rempfler 2025, dissertation). What the high hunt means for wild animals is shown by our dossier on the high hunt in Switzerland.

Loss of lead animals and the breakdown of social structures

The impact of recreational hunting on social wildlife communities is especially serious. Many huntable species are not loners but live in family groups with well-established hierarchies, communication structures and experienced lead animals.

Wild boars (sounders): Wild boars live in family groups led by an experienced lead sow. She knows the sleeping places, food sources and escape routes. If she is shot, the sounder can lose its bearings, and inexperienced young animals seek to join other groups. A Europe-wide analysis shows how the type of hunting changes social contacts within sounders (Podgórski et al. 2026). On top of this, under high hunting pressure sows reproduce earlier and more often (Servanty et al. 2009). This dossier on the wild boar in Switzerland documents this mechanism in detail.

Red deer (hinds): Red deer, too, live in maternal families. Experienced hinds know migration routes, resting areas and dangerous places. Long-term data from the Scottish island of Rum show that when a calf loses its mother, its risk of dying increases (Andres et al. 2013), and hinds with strong social bonds live longer and have more offspring (Ruckstuhl, Sosa and Clutton-Brock 2026). The Office for Hunting and Fisheries of the canton of Grisons itself acknowledges that orphaned red deer calves become socially stunted and have a high mortality rate.

Roe deer: Roe deer are less social than red deer or wild boars, but nor are they strictly solitary animals. When bucks are shot, territories become vacant and are reoccupied, which can bring additional unrest into the population.

Compensation: when hunting achieves the opposite of regulation

One of the best-documented phenomena in wildlife biology is compensation: when animals are removed through hunting, the remaining ones make up for the losses through higher reproduction, better survival rates and immigration. Hunting therefore often fails to reduce the population permanently.

This is particularly evident in wild boars: under hunting pressure, young sows become pregnant earlier, and sustained hunting pressure accelerates reproduction (Servanty et al. 2009; Mazzatenta 2026). In Spain, the hunting bag rose from 32,000 animals in 1985 to 450,000 in 2022, despite a declining number of recreational hunters (Gortázar et al. 2026).

The effect is also documented in the fox: in France, immigration offset even high kill rates for years (Lieury et al. 2015), and local culling does not reduce fox density at the landscape level (Kämmerle et al. 2019). In such cases, recreational hunting regulates nothing; it merely supplies the justification for yet more hunting.

Stress hormones in game meat: what are we actually eating?

Stress before death also changes the meat. Animals that are killed in an exhausted state after a driven or drive hunt show higher stress levels than animals shot from a high seat.

This was measured in a study of 407 wild boars: after drive hunts, the stress hormone cortisol in the blood averaged 431 nmol/l, after hunting in an enclosure 325 nmol/l, and after individual hunting from a high seat 119 nmol/l. Meat from drive hunts and enclosure hunts showed elevated pH values and altered colour values, which the researchers interpret as stress-related metabolic effects (Kelava Ugarković et al. 2025).

For consumers who perceive game meat as "natural" and "low-stress", this is relevant information. "Natural" does not automatically mean "experienced with little stress". More on this in our dossier on driven hunts.

The comparison: hunting-free vs. hunted

The canton of Geneva has done without recreational hunting since 1974. Intervention now takes place only in a targeted way by professional environmental wardens, mainly in the case of wild boars. The dossier on the Geneva hunting ban contains detailed information on the Geneva model.

Roe deer in the canton of Geneva also use open areas during the day and venture close to settlements. This matches the research: in a camera-trap study in the Bavarian Forest National Park, red deer, roe deer, wild boar, fox and lynx avoided humans more strongly the higher the hunting pressure was (Peters et al. 2025). In the case of the Alpine marmot, only hunting, not recreational use, influenced how tolerant the animals were towards humans (Zenth et al. 2025).

The Swiss National Park also offers a point of comparison. Here, where there has been no hunting since 1914, red deer and chamois can often be observed by hikers at close range. Radio-collared red deer there choose their habitat largely independently of human influence (Rempfler et al. 2025).

Cambridge Declaration on Consciousness 2012: Animals experience suffering

The Cambridge Declaration on Consciousness of 2012 provides a scientific foundation for the ethical assessment of hunting stress. In it, leading neuroscientists stated that non-human animals possess the neurological substrates required for states of consciousness. This includes all mammals, all birds and many other animals, and therefore all huntable wildlife species in Switzerland.

In concrete terms, this means that wild animals can subjectively experience fear, pain, stress and suffering. This is not anthropomorphism but scientific consensus. An ethical obligation follows from this: anyone who exposes wild animals to a situation that demonstrably causes stress bears moral responsibility.

The Swiss Animal Welfare Act reflects this consensus, at least formally. It defines dignity as the intrinsic value of the animal and states: «Animal dignity is disregarded if a burden placed on the animal cannot be justified by overriding interests» (Art. 3 let. a TSchG). No one may unjustifiably cause an animal fear (Art. 4 para. 2 TSchG). Whether the leisure interests of around 30,000 recreational hunters justify chronic stress in hundreds of thousands of wild animals is a question that the dossier Ending recreational violence against animals.

The concept of quiet zones: a way out?

In response to the research findings, some cantons and municipalities have established wildlife protection areas and quiet zones. The idea: certain areas are kept free of disturbance all year round. Wild animals can retreat and recover undisturbed, and the areas act as a source for the surrounding populations.

That refuges work is well documented. In the Central Alps, radio-collared red deer chose their habitat within networks of wildlife reserves largely independently of human influence (Rempfler et al. 2025). In the case of the rock ptarmigan, flight distances remained constant throughout the year in hunting-free areas (Sooth et al. 2026). The hunting lobby nevertheless rejects area-wide quiet zones: they would increase hunting pressure in the remaining areas. Critics counter that the solution would be less hunting, not fewer quiet zones.

In Switzerland, the cantons can designate wildlife quiet zones on the basis of Art. 7 para. 4 of the hunting act, but they are under no obligation to do so. Only the National Park and the federal hunting reserves are permanently closed to hunting, although regulatory kills remain permitted there.

Driven hunts: the most extreme stress event

Of all hunting methods, driven hunts and drive hunts produce the highest acute stress. People, dogs and noise drive entire groups of wild animals towards the shooters. A study by the University of Veterinary Medicine Hannover found elevated cortisol levels in all samples from wild boars taken in drive hunts (Güldenpfennig et al. 2021), and after drive hunts the levels were almost four times as high as after single hunting from a high seat (Kelava Ugarković et al. 2025).

That driven hunts are nonetheless the most popular form of communal hunting in Switzerland has little to do with efficiency and much to do with social ritual. Our dossier on driven hunts examines the methodology, the effects and the question of whether this form of hunting is compatible with modern animal welfare standards.

Conclusion: hunting stress is scientifically proven and ethically relevant

The research shows: recreational hunting causes acute and chronic stress in wild animals. It alters their behaviour and use of space, interferes with social structures and, through compensation, can even undermine the stated goal of population regulation.

In light of the Cambridge Declaration on Consciousness and the Swiss animal welfare act, the question arises whether chronic hunting stress in hundreds of thousands of wild animals can be justified by leisure interests, legally, ethically and scientifically. This question is rarely asked. It is time to ask it.

Further content on wildbeimwild.com:

• Hunting fact check: the state of the research
• Dossier: Psychology of Hunting
• Dossier: Driven hunt
• Dossier: Ending recreational violence against animals
• Dossier: The high hunt in Switzerland
• Dossier: Geneva and the hunting ban
• Dossier: The wild boar in Switzerland

You can find more background on current hunting policy in Switzerland in our dossier on wildbeimwild.com.