Climate change and birds breeding on the Halligen

Coastal birds breed in exceptionally large numbers and high densities on the Halligen in the Schleswig-Holstein Wadden Sea and these populations are of considerable importance both nationally and internationally. With around 4,500 breeding pairs, about 15 % of the total German oystercatcher population breed on the Halligen. The Sandwich tern colony on the Hallig of Norderoog represents a proportion of over 70 % of the German breeding population. Breeding success is exeptionally high on the Halligen due to a lack of ground-foraging predators among other reasons.

In the future, the Halligen will be particularly affected by sea level rise, resulting in more frequent flooding. This will impact the people living there but also the avifauna and in particular the breeding birds due to changing structures and habitats.

As well as more frequent flooding representing an imminent threat for nests and young birds, indirect results of rising sea levels may also cause risks. Among these are coastal protection measures like embankment reinforcements, which enable mammalian predators (foxes, mustelids and others) to reach the Halligen. Modifications in agricultural land use will also result in structural and partly negative changes.

The main objective of this study is to describe possible future or already apparent impacts of climate change on the breeding birds. Possible solutions to protect these birds are identified. The study aims to contribute to the development and assessment of suitable measures and to provide guidance for necessary further investigations. Sources of literature were evaluated and locals and experts interviewed. The study addresses both the inhabitants of the Halligen and stakeholders in nature conservation and coastal protection.

The expert report was compiled on behalf of WWW Germany and is part of the research study Land unter im Wattenmeer.

It was part of the “PiKKoWatt – pilot measures for adaptation to climate change with communities in the Schleswig-Holstein Wadden Sea region” project.

You can download the research study Land unter im Wattenmeer. Auswirkungen des Meeresspiegelanstiegs auf die Natur der Halligen und Möglichkeiten zur Anpassung from the website of the WWF Germany.