RapportWaterbirds in the international Rhine Valley: numbers, distribution and trends

This report provides the third review of wintering waterbirds in the international Rhine Valley in the framework of the working programme of the International Commission for the Protection of the Rhine (ICPR). Counts of waterbirds have a long tradition along the Rhine, being part of national census schemes in Switzerland, France, Germany and The Netherlands.

The compilation of data for this report focusses on the current status of waterbirds in the international Rhine Valley in the period 2016–2018 (winter seasons 2015/16–2017/18) and presents population trends since 1981.

On average, maxima of over 1.1 million native waterbirds were present at the Rhine Valley in the winters 2015/16 – 2017/18. They represent 70 bird species of which 25 species occurred in internationally relevant numbers (i.e. >1% of the flyway population). In 1999/2000 these were 21 species, expressing not only genuine increases but also improved coverage in some species. When comparing the number of birds between the six river stretches distinguished, it becomes clear that about half of the numbers of waterbirds is supported by the lake ecosystems of Bodensee IJsselmeer, Markermeer and Randmeren (Borderlakes) and half by the branches of the river Rhine itself.

The most common species group along the Rhine consist of ducks and Eurasian Coot, followed by swans and geese. In the Southern Rhine ducks and Coot dominate the waterbird community, in the North this position is shared between ducks/Coot and swans and geese. Other species groups as gulls, waders and grebes and herons (and allies) are much less numerous compared to the other groups but involve many species. In addition to native waterbird species, also 14 non-native waterbird species have been found in the Rhine Valley in the wild. This group is clearly increasing.

van Roomen, M., Hustings, F., van Winden, E., Dronneau, C., Frauli, C., Strebel, N.,Wahl, J., Koffijberg, K. & van Turnhout, C. 2020. Waterbirds in the international Rhine Valley: numbers, distribution and trends ICPR rap nr. 277, Sovon rap nr. 2020/99. International Commission for the Protection of the Rhine, Koblenz.