Switzerland with its many lakes and rivers is a very important wintering site for waterbirds. As a consequence, monitoring of population size and distribution during the winter focuses on this group. For decades, waterbirds have been counted twice every winter on all important sections of rivers and lakes. Switzerland has an international responsibility for several species. These have therefore been classified as national priority species. Many other species that are not dependent on water bodies are monitored – like the migrants – through the programme Rare Breeding and Visiting Birds.
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. Kostyushin, A. Kozulin, L. Lawicki, L. Luigujoe, C. Müller, P. Musil, Z. Musilová, 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. Wildfowl 66: 22–40.
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. Langendoesn, 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 EurasianWigeon (Anas penelope) in northwest Europe