The status of the riverside runner (Actitis hypoleucos) in the Gesäuse National Park

Diploma thesis at Karl-Franzens-Universität. In recent decades, the number of rivers with natural water and slurry management has been largely reduced by water engineering projects such as shore fortifications, flood safety measures and power plant constructions. One of the main victims of this development in Central Europe is the riverside runner, which belongs to the highly endangered species according to the Red List of endangered breeding birds of Styria and the Red List of Birds of Austria. Its distribution priorities are, due to the above-mentioned measures very rare, flowing waters with a wild river character, i.e. with more or less strong gully conduction. The Gesäuse National Park in Obersteiermark includes a 9 km long section of the Enns with wild river character. Here there are natural gravel banks and islands, which would be ideal as a breeding habitat for the riverside runners. However, precise surveys on stock and breeding status took place for the first time in 2003, with two broods detected. This short, natural section of the Enns is intensively used for various water sports and by tourists. In addition to the shore and power plant constructions, the recreational and leisure activities during the breeding season are another cause of danger. Walkers, boat operators (rafting, kayaking) with and without landing at gravel banks, bathers and other things have an impact not only on the habitat, but also on the behaviour of the birds. In the worst case, it even comes to the abandonment of the nesting place and thus the emigrating of the riverside runner from the area. One of the aims of this diploma thesis is to document the stock as well as the spatial distribution of the riverside runner and its breeding status in the Gesäuse National Park. A more detailed study of populated gravel banks is intended to identify differences in habitat use in order to identify a preference for certain types of substrates or structures.