Authors: Bötsch, Yves; Krahn, Louiza;Remmers, Tim;Korossy-Julius, Laurens;Zöckler, Christoph;Hunke, Philip;Hötker, Hermann;

Agricultural intensification and drainage of wet grassland reduced the breeding habitat of many grassland waders in Europe. Therefore, re-wetting of drained grassland is the most applied conservation intervention in restoring the breeding habitat of waders. From 2019-2021 we assessed and compared rewetted (winter-flooded) sites (n=28) with drained sites in terms of food availability. We sampled transects at the sites for three different prey-items – benthos-animals, soil-invertebrates and arthropods. Benthos organisms were more abundant in longer flooded sections, whereas earthworms and tipulidae-larvae strongly declined in flooded areas. Arthropods did not show any preference, but were indirectly affected through inhibited vegetation growth when flooded. Overall, re-wetting is beneficial for wet grassland breeding waders in many aspects, but a mix relief of flooded and dry sites should be favoured, as they serve as retreating sites for earthworms. It also speeds re-colonisation of flooded sites after they dried out and dry sites are as well needed as breeding ground for waders. A mosaic of wet and dry sites suits all the different prey types, creates a heterogeneous vegetation structure and therefore suits many different grassland breeding waders, which all have their own habitat preferences.