The Reconquest

Monitoring Red Deer in the Swiss Plateau

It’s hard to imagine today, but in 1850, the red deer was extinct in Switzerland. This was due to the overexploitation of the forests and hunting.

It was only stricter forestry and hunting laws that turned the tide. Starting in 1870, red deer began migrating from Austria into the canton of Graubünden. Currently, the “king of the forests” is also slowly making its way into the Swiss Plateau. In recent years, this expansion has occurred particularly along the Albis Range and in the Reuss Valley.

Research on the Albis Range and the Reuss Valley

The return of this large herbivore to this heavily human-shaped cultural landscape can give rise to conflicts over land use, the resolution of which requires fact-based management principles. For this reason, the Federal Office for the Environment commissioned a comprehensive research program in which several universities of applied sciences participated. The ZHAW Wildlife Management Research Group focused on the Albis Range–Reuss Valley region.

Using 95 wildlife cameras, the ZHAW research team monitored an area of 450 square kilometers between May 2020 and April 2024. In addition, the researchers were able to fit three female and three male red deer with GPS neck collars in the Sihlwald area.

In the camera trap monitoring, red deer were detected in 71 of a total of 95 square kilometers. An estimated 100 animals live in the region. No sightings were recorded near the city of Zurich or along the Limmat Valley, for example.

Red deer prefer areas that are as far away from human structures as possible, have a high proportion of forest, and offer good cover. They generally only venture into open areas under the cover of darkness, even though red deer are naturally diurnal.

In winter, red deer favor the Sihlwald

Interesting fact: The regional distribution of red deer is strongly seasonal. In winter, red deer are clearly concentrated in the Sihlwald area. During the rest of the year, the animals roam widely throughout the study area. Does are generally much more sedentary than stags. Some stags undertook migrations as far as the Pre-Alps; one stag even wandered as far as the foot of Mount Pilatus in the canton of Lucerne—covering distances of up to 35 kilometers.

Conclusions of the research team: The Sihlwald has proven to be a central refuge area for red deer and plays an important role in the regional connectivity of the population. The map below illustrates this. The cameras that photographed red deer one or more times between May 2022 and April 2023 are marked in red. At the other camera locations, there was no evidence of red deer.

Wildlife crossings over roads

In an ecologically oriented, integrated red deer management approach, targeted hunting measures should be skillfully combined with the promotion of important refuge areas. This includes habitat-calming measures such as trail closures, mandatory leashing of dogs during sensitive seasons, and the establishment of wildlife quiet zones. The expansion of ecological infrastructure—for example, through wildlife bridges and other crossing aids—must be consistently continued to ensure connectivity for red deer and other wildlife species.

Deer at Langenberg Wildlife Park.

The red deer was the first species to be kept at Langenberg Wildlife Park, which was founded in 1869. Today, fallow deer from Asia and the Vietnamese sika deer – which is extinct in the wild – also live here. The Wildnispark Zurich foundation participates in the international conservation breeding programme for this deer species in order to secure a reserve population and thus enable its reintroduction.

There are between 50 and 80 species of deer worldwide – depending on the method of counting or the classification of subspecies.