The Swiss plateau as a bottleneck: why the lynx needs more than presence

The lynx is spreading across the Swiss plateau, of all places where experts long considered the landscape too densely populated and too fragmented.

A new analysis by the KORA foundation for the years 2020 to 2025, based on GPS telemetry, camera traps and genetic samples, shows: in the southern Swiss plateau between Bern, Fribourg and Vaud, several female lynx are successfully raising offspring. The female lynx Mona is considered an early pioneer; the first documented reproduction of a lynx in the Swiss plateau involved her back in 2012.

The obvious headline would be: the lynx is doing fine. It is wrong, or at least dangerously oversimplified. Because for the Swiss lynx, the Swiss plateau is not just one additional habitat among many. It is a bottleneck upon which the future of the entire species in Switzerland depends.

Why location is decisive

Swiss lynx occurrences are monitored and assigned to the Jura, Alps and North-East Switzerland populations. For the biological year 2024/2025, KORA estimates the population at 364 ± 10 independent lynx, meaning subadult and adult animals over one year of age. Of these, 246 ± 9 lived in the Alps, 86 ± 6 in the Jura and 32 ± 3 in North-East Switzerland. Juveniles still living with their mother are not included in this estimate.

These populations descend from a small number of reintroduced animals and are in some cases separated from one another both spatially and genetically. The southern Swiss plateau is therefore not merely additional habitat, but a potential connecting space between the Jura and the Alps. Whether this connection functions permanently will help determine whether Swiss lynx populations remain resilient in the long term. How precarious the link between species protection, habitat and political pressure remains to this day is also shown by the dossier «The lynx in Switzerland: predator, keystone species and political bone of contention».

The difference between presence and connectivity

This is the core point that standard reporting misses. What matters is not simply whether lynx appear in the Swiss plateau, but whether they use safe migration routes, survive and leave offspring. Why such connections are essential for animals in a heavily built-up Switzerland is explained in «Wildlife corridors in Switzerland: function, facts and hunting criticism».

Three levels must be kept strictly separate here: a sighting only proves presence. A motorway crossing only proves movement. Only genetic evidence of offspring from two previously separate populations demonstrates actual functional connectivity.

Genetic diversity is not an abstract figure here. It determines how well a population can cope with disease, changing environmental conditions and other pressures. KORA explicitly points to the risk of inbreeding and less resilient animals if connectivity fails to materialise. A mere rise in the number of animals counted therefore does not answer the crucial question: whether the populations connect permanently and remain resilient.

The ongoing KORA project «Lynx Project GGD 2024 to 2026» therefore focuses precisely on this: the connection between the Jura and the Alps, the colonisation of the Swiss plateau, genetic samples in potential corridors, as well as health and reproduction. Hair samples from natural marking sites are intended to show which individuals actually use the corridors and whether offspring result from this.

Wildlife bridges: necessary, but no alibi

A wildlife bridge is not a symbolic structure and no substitute for intact habitats. It can only function if it is part of a continuous network: with suitable forest links, hedges, woodland patches, cover, low-disturbance refuges and safe connections on both sides. Where feeder routes are missing, settlements grow, or recreational use degrades the surrounding area, even the most expensive crossing remains an isolated island. Wildlife bridges and underpasses are therefore not decorative features of transport policy, but part of an ecological infrastructure: Wildlife bridges and spatial planning are more effective than kills, because they enable animals to cross transport routes and connect populations with one another.

The findings of the Federal Office for the Environment (FOEN) lend weight to this criticism. FOEN counts 304 wildlife corridors of supra-regional importance nationwide. Of these, 47, or 16 percent, are largely interrupted; a further 171, or 56 percent, are significantly to severely impaired. Only 86 corridors, 28 percent, are considered intact. In other words: almost three-quarters of those connections that are important for the large-scale exchange of wild animals do not function without restriction.

For the lynx, this is particularly serious, because its survival as a species in Switzerland depends on exchange between subpopulations. The state fundamentally acknowledges the importance of these connections: since 2003, the Federal Roads Office (ASTRA), FOEN and the cantons have been working on remediation along national roads. The gap lies not in the intent, but in the pace of implementation and the condition of the overall network.

Fribourg provides a concrete example. At the FR-23 wildlife corridor near Vaulruz, a lynx died in a traffic collision in 2022; later, another lynx was run over in the same area. For FR-23, a wildlife crossing over the A12 is planned, along with improvements through hedges and field woodland. The canton is planning the remediation of the FR-16 and FR-23 corridors; FR-23 has been included as a pilot project in the action plan of the Swiss Biodiversity Strategy.

That corridors can work is shown by the same region: the female lynx ELYN, living in the Fribourg plateau, used the FR-06 corridor to cross the A12 in spring 2023, even though it was not originally built specifically for lynx. Accessibility and permeability are what matter, not the label attached to the structure.

The political conclusion is clear: wildlife bridges must not serve as isolated compensation measures while habitats elsewhere continue to be built over and corridor connections degraded. What is needed is a binding network, not a single PR-friendly structure.

Traffic: the loss of the migrating animals

Roads and railway lines do not affect lynx evenly. Juveniles and subadult lynx are particularly at risk when they search for their own territory after separating from their mother. Yet it is precisely this dispersal that is the mechanism by which new habitats are colonised and previously separated populations become genetically connected. Whoever loses the migrating animals loses the connectivity. How far individual lynx travel in search of a territory, and what barriers they must overcome, is shown by the case of «Lynx Juro swims from the Black Forest into Switzerland».

With 60 known losses, recorded lynx mortality reached a record in 2025 since the lynx was reintroduced in Switzerland. Juveniles in their first year of life are found particularly often; subadult animals searching for territory and adult animals are also affected. KORA lists traffic accidents, disease and illegal killings as relevant causes of death. Every loss of a migrating animal can sever a potential connection between two subpopulations.

Poaching: known cases are minimum figures

Poaching represents a systematic protection gap for the lynx, because it is difficult to detect. A traffic victim is, in many cases, found, examined and recorded. An illegally shot, poisoned or hidden animal, on the other hand, can disappear without a cause of death ever being established. The number of proven cases therefore never reflects the full extent of the problem.

KORA explicitly cites poaching alongside traffic and disease as a cause of lynx losses. At the same time, the fragmented landscape makes it harder to connect populations. This combination is particularly problematic for a small, genetically strained population: when a migrating or reproductively capable animal disappears, it is not only an individual that is lost, but potentially a building block for exchange between the Jura and the Alps.

Serious reporting must acknowledge both sides: not every animal that disappears is demonstrably the victim of an illegal killing. But the number of confirmed cases is equally unsuitable as reassurance, because the number of unreported cases involving offences against wild animals can hardly be reliably quantified by any methodology. For Switzerland, numerous illegal killings have been documented over decades, using methods ranging from shooting to poisoning to trapping with steel traps. An older evaluation of radio-collared lynxes concluded that illegal killings accounted for a significant proportion of identified causes of death. However, no current nationwide rate can be derived from this. Compounding the problem: Switzerland has no nationwide, publicly accessible poaching statistics.

The editorial core

The Central Plateau is no proof that the lynx can make it alone. It is the bottleneck at which it will be decided whether genetically weakened populations, long separated from one another, can become a long-term viable Swiss lynx population.

What matters is not PR images of individual wildlife bridges, nor merely a rising number of records. What matters is whether wildlife corridors are legally secured, restored and protected in the long term from further development. What matters is whether motorways and railway lines are defused with effective crossings, fences and guiding structures. What matters is whether those animals that migrate between the Jura and the Alps, enabling genetic exchange, survive.

This includes systematic monitoring of crossing use and reproduction, the ecological upgrading of corridor connections, forensic examination of every lynx found dead, and transparent recording and consistent prosecution of illegal killings.

As long as these conditions are not met, additional kills are not a responsible form of 'regulation', but additional pressure on a species whose connectivity is still failing due to the human-made fragmentation of the landscape. The lynx in the Central Plateau does not primarily need 'acceptance' as an abstract buzzword. It needs a permeable landscape and fewer human-made causes of death.