Monitoring wintering waterbirds

Since 1967 waterbirds are counted throughout Europe and in adjacent regions. This international waterbird census is coordinated by Wetlands International. The waterbird census is an important tool to estimate population size and trends of birds and to identify important wintering sites.

Aims

Monitoring population trends and distribution of wintering populations of waterbirds.
Identification of sites of international and national importance for waterbirds.
Monitoring waterbird populations in waterbird reserves of international and national importance listed in the federal inventory.
Compiling basic information for the conservation of wintering waterbirds in Switzerland, in particular in the framework of the federal hunting legislation.

Approach

Volunteer collaborators of the Swiss Ornithological Institute count all waterbirds every year in mid-November and mid-January. All the major waterbodies and a number of smaller lakes and rivers in Switzerland are covered. In the waterbird reserves of international importance monthly counts are carried out in collaboration with regional organisations. Data are stored in a national database and forwarded to Wetlands International for incorporation in the database of the International Waterbird Census. Results are published in annual reports.

Significance

Based on the waterbird counts, the Swiss Ornithological Institute has compiled inventories of waterbird sites of international and national importance. These inventories served as the basis for the waterbird reserves established by the federal authorities.

Results

The most recent annual report (in German and French) can be found here. Previous reports are listed under publications.

Volume 6 of the series «Avifauna Report Sempach» gives an overview on the history of the census, population trends and the importance of Switzerland and the main lakes and rivers for waterbirds outside the breeding season. The report is available in German and French.

In addition, detailed results can be downloaded via the following Excel files:

Overall Swiss population of all species from 1967 (January) or 1991 (November) until 2021/2022.
Number of individuals per species and site: season 2021/2022
Proportion of overall Swiss population in reserves of international importance: season 2021/2022
Monthly population numbers in each reserve of international importance: season 2021/2022

Pavón-Jordán, D., P. Clausen, M. Dagys, K. Devos, V. Encarnaçao, A. D. Fox, R. Frost, C. Gaudard, M. Hornman, V. Keller, T. Langendoen, L. Lawicki, L. J. Lewis, S.-H. Lorentsen, L. Luigujoe, W. Meissner, B. Molina, P. Musil, Z. Musilova, L. Nilson, J.-Y. Paquet, J. Ridzon, A. Stipniece, N. Teufelbauer, J. Wahl, M. Zenatello & A. Lehikoinen (2019):
Habitat- and species-mediated short- and long-term distributional changes in waterbird abundance linked to variation in European winter weather.

Strebel, N. (2019):
Überwinternde Wasservögel in der Schweiz: Ergebnisse der Wasservogelzählungen 2018/2019.

Strebel, N. (2018):
Überwinternde Wasservögel in der Schweiz: Ergebnisse der Wasservogelzählungen 2017/2018.

Strebel, N. (2017):
Überwinternde Wasservögel in der Schweiz. Ergebnisse der Wasservogelzählungen 2016/2017.

Fox, A. D., A. Caizergues, M. V. Banik, K. Devos, M. Dvorak, M. Ellermaa, B. Folliot, A. J. Green, C. Grüneberg, M Guillemain, A. Haland, M. Hornman, V. Keller, A. I. Koshelev, V. A. Kostiushyn, A. Kozulin, L. Lawicki, L. Luigujõe, C. Müller, P. Musil, Z. Musilova, L. Nilsson, A. Mischenko, H. Pöysä, M. Sciban, J. Sjenicic, A. Stipniece, S. Svazas & J. Wahl (2016):
Recent changes in the abundance of Common Pochard Aythya ferina breeding in Europe.

Fox, A.D., L. Dalby, T.K. Christensen, S. Nagy, T.J.S. Balsby, O. Crowe, P. Clausen, B. Deceuninck, K. Devos, C.A. Holt, M. Hornman, V. Keller, T. Langendoen, A. Lehikoinen, S-H. Lorentsen, B. Molina, L. Nilsson, A. Stipniece, J-C. Svenning & J. Wahl (2016):
Seeking explanations for recent changes in abundance of wintering Eurasian Wigeon (Anas penelope) in northwest Europe

Strebel, N. (2016):
Wintering Waterbirds in Switzerland. Results of the Swiss Waterbird Census 2014/2015 and 2015/2016.

Müller, C. & V. Keller (2015):
Monitoring Überwinternde Wasservögel: Ergebnisse der Wasservogelzählungen 2013/14 in der Schweiz. Monitoring hivernal des oiseaux d'eau : Résultats des recensements des oiseaux d'eau 2013/14 en Suisse

Keller, V. & C. Müller (2014):
Monitoring Überwinternde Wasservögel: Ergebnisse der Wasservogelzählungen 2012/13 in der Schweiz. Monitoring hivernal des oiseaux d'eau: Résultats des recensements des oiseaux d'eau 2012/13 en Suisse

Müller, C. & V. Keller (2013):
Monitoring Überwinternde Wasservögel: Ergebnisse der Wasservogelzählungen 2011/12 in der Schweiz / Monitoring hivernal des oiseaux d'eau: Résultats des recensements des oiseaux d'eau 2011/12 en Suisse.

Keller, V. (2011):
Die Schweiz als Winterquartier für Wasservögel.

Keller, V. (2011):
La Suisse, refuge hivernal pour les oiseaux d’eau.

Keller, V. & M. Burkhardt (2011):
Monitoring Überwinternde Wasservögel: Ergebnisse der Wasservogelzählungen 2009/10 in der Schweiz / Monitoring hivernal des oiseaux d'eau: Résultats des recensements des oiseaux d'eau 2009/10 en Suisse.

Keller, V. & M. Burkhardt (2010):
Number and distribution of Great Cormorants Phalacrocorax carbo in Switzerland in January 2009.

Keller, V. & M. Burkhardt (2010):
Monitoring Überwinternde Wasservögel: Ergebnisse der Wasservogelzählungen 2008/09 in der Schweiz / Monitoring hivernal des oiseaux d'eau: Résultats des recensements des oiseaux d'eau 2008/09 en Suisse.

Keller, V. & M. Burkhardt (2009):
Monitoring Überwinternde Wasservögel: Ergebnisse der Wasservogelzählungen 2007/08 in der Schweiz / Monitoring hivernal des oiseaux d'eau: Résultats des recensements des oiseaux d'eau 2007/08 en Suisse.

Keller, V. (2008):
Gli uccelli acquatici svernanti sui laghi ticinesi: una panoramica sui risultati dei censimenti dal 1967.

Keller, V. & M. Burkhardt (2008):
Monitoring Überwinternde Wasservögel: Ergebnisse der Wasservogelzählungen 2006/07 in der Schweiz / Monitoring hivernal des oiseaux d'eau: Résultats des recensements des oiseaux d'eau 2006/07 en Suisse.