Capercaillie

The Capercaillie, the largest of all grouse species, lives in conifer-dominated, open mountain forests with well-developed bilberry shrub layers and little disturbance by humans. Three nationwide censuses carried out in 1968/71, 1985 and 2001 have shown a clear negative trend in both population numbers and geographical range in Switzerland.

Aims

The aim of the project is to ensure the long-term survival of Capercaillie as a breeding species in Switzerland. To achieve this goal, improvement of habitat quality of currently inhabited forests and their protection from human disturbance are important steps. In addition, connectivity among the distinct subpopulations in Switzerland has to be increased.

Approach

The Swiss Ornithological Institute is responsible for monitoring Capercaillie population trends and the geographic range in Switzerland. We closely work together with cantonal gamekeepers and many volunteers. Currently, we are developing a new monitoring method based on indirect cues of the species' presence (droppings, feathers, footprints) rather than on counting the birds directly as has been previously done. The new method should help to significantly reduce the disturbance caused during direct population counts.

Together with the Federal Office for the Environment FOEN and Swiss Association for the Protection of Birds SVS/BirdLife Switzerland, the Swiss Ornithological Institute has published the nationwide Capercaillie action plan in 2008. The Swiss Ornithological Institute assists forest managers and landowners intending to implement forestry measures in favour of Capercaillie. Further, the Swiss Ornithological Institute is regularly consulted when forestry roads are to be built or when orienteering races are to be planned in Capercaillie habitats.

Significance

• Monitoring populations of a forest-dwelling species sensitive to human disturbance.
• Estimating population size based on genetic fingerprinting with DNA from droppings.
• Assessment of forestry measures in favour of Capercaillie and establishment of cooperation with forest managers, landowners and policymakers in federal, cantonal and communal governments.

Results

Forest reserves in favour of Capercaillie have been established and are planned, respectively, in several cantons (Schwyz, Zug, St. Gallen, Obwalden, Nidwalden, Bern, Luzern). The Swiss Ornithological Institute was involved in the drafting of the forestry measures and in the planning of the performance control in these reserves.

According to thePhD thesis of Dominik Thiel carried out at the Institute, Capercaillie corticosteroid levels were positively related to the intensity of human disturbance in their winter habitats. This underlines the importance of measures to mitigate human disturbance in Capercaillie core areas.

The analysis of DNA from droppings allows to individually identify Capercaillies via genetic fingerprinting. The combination of genetic data and capture-mark-recapture statistics makes it possible to estimate the size of Capercaillie populations with unprecedented accuracy and reliability. The method has been successfully applied in two projects in the cantons Obwalden and Schwyz. The analyses are completed and a manuscript is in preparation.
carried out at the Institute, Capercaillie corticosteroid levels were positively related to the intensity of human disturbance in their winter habitats. This underlines the importance of measures to mitigate human disturbance in Capercaillie core areas.

The analysis of DNA from droppings allows to individually identify Capercaillies via genetic fingerprinting. The combination of genetic data and capture-mark-recapture statistics makes it possible to estimate the size of Capercaillie populations with unprecedented accuracy and reliability. The method has been successfully applied in two projects in the cantons Obwalden and Schwyz. The analyses are completed and a manuscript is in preparation.

Project management

Pierre Mollet

Partners

Dr. Kurt Bollmann, Swiss Federal Institute for Forest, Snow and Landscape Research WSL
Federal Office for the Environment FOEN

Financial support

Marion J. Hofer-Woodhead-Stiftung
Messerli-Stiftung Zürich
Sielmann-Stiftung
Wofona-Stiftung Vaduz
Ausbildungsstiftung für den Kanton Schwyz und die Bezirke Gaster und See (Kanton St. Gallen)
Stiftung Naturland

Publications