Decline in breeding birds in the Ahrmündung nature reserve: Alarming findings!

Decline in breeding birds in the Ahrmündung nature reserve: Alarming findings!

The biodiversity in the Ahrmündung nature reserve near Sinzig is the focus of a current study by biologists from the University of Osnabrück and the Bonn Ornithological Association. In their comprehensive study, which was published in the European Journal of Ecology, the researchers shed light on the long-term changes in breeding bird species in this protected area. The comparative study is based on mapping from 1984, 2020 and 2022 and has shown that the decline in biodiversity is not primarily due to the 2021 flood disaster, but rather to long-term ecological changes.

What is particularly striking is the increase in the population of bush and forest species such as the blackcap and the chiffchaff since 1984. In contrast, there has been a sharp decline or even the complete disappearance of open-land species, including the marsh warbler, the common chiffchaff and the tree sparrow. This dynamic poses a challenge to the goals of area management, which aims to promote both riparian forest and openland species.

Influence of flood and habitat structure

The Ahr flood in June 2021 surprisingly had little impact on bird life. The overall long-term development of the area proved to be crucial for the observed population changes. Only the populations of individual undergrowth species were slightly reduced in the year following the flood. Another problem is the use of fat meadows, which are rarely used as breeding grounds in the south and northeast of the protected area. Despite stopping fertilization and regular mowing, these meadows are overgrown, which worsens breeding conditions for many bird species.

Disturbances from dog owners and the lack of structuring measures, such as grazing on pastures, also contribute to the unfavorable conditions. The researchers recommend extensifying the fat meadows through grazing, possibly with water buffalo, to improve habitats for open-land species. This measure was already discussed before the flood, but was not pursued further.

Conclusion and outlook

Overall, the study shows University of Osnabrück that the long-term changes in the Ahrmündung nature reserve are crucial for the decline in breeding bird species. It remains to be hoped that the scientists' recommendations for improving habitats will be taken seriously in order to sustainably promote and preserve biodiversity in this important nature reserve. In addition, the regionalupdate.de the research results and highlights the importance of preserving these habitats. The challenges are great, but hopefully positive developments can be achieved with a targeted approach.