Species Overview and Ecological Issues

The ruddy duck, native to North America, is a diving duck species that was accidentally introduced to Europe in the late 20th century. Highly prolific and adaptable, it quickly established itself in several European countries. This invasive species poses a major threat to the white-headed duck (Oxyura leucocephala), a native species at risk of extinction, protected under the Bern Convention and listed in Appendix II. The main threat is hybridization between the two species, which jeopardizes the genetic survival of the white-headed duck, as well as competition for resources and habitat.

The Bern Convention’s Commitment

Under the Bern Convention, signed in 1979, Parties are required to protect threatened and vulnerable species. The ruddy duck, recognized as an invasive alien species, has been the subject of a pan-European eradication action plan coordinated by the Convention since 1999.

This action plan has been regularly revised to incorporate scientific advances and lessons learned, notably in 2010, 2016, and 2020. The main objective is to eradicate the ruddy duck in the Western Palearctic region to protect and restore white-headed duck populations.

The Pan-European Action Plan for Ruddy Duck Eradication

The Action Plan serves as a strategic framework for Bern Convention Parties, who are expected to develop and implement national and regional control and eradication programmes. It includes concrete measures such as:

• Annual monitoring of the distribution and status of ruddy ducks in the wild, with sufficient resources allocated for effective surveillance.

• Active and reactive control operations (targeted capture and culling), conducted in accordance with national regulations, aiming for the functional extinction of the species in the wild.

• Management of captive individuals, including inventorying held specimens, assessing and reducing the risk of accidental introduction, and preventing any new import, sale, or captive breeding.

• International coordination and cooperation, including information exchange, synchronizing actions among affected States, and submitting annual reports to the Standing Committee of the Bern Convention.

• Regular evaluation of progress, with strategy adjustments as needed.

Results and Challenges

By 2024, coordinated efforts at the European level have significantly reduced ruddy duck populations in the main affected countries. The United Kingdom is close to eradication, with only a few isolated individuals and very little breeding observed. In Belgium and Germany, the population remains marginal, though some nesting cases persist (the population in Germany is dispersed and poorly controlled). The issue also remains in France, despite a reduction in numbers. In the Netherlands, most remaining birds (about 75 individuals) are now concentrated in a limited area. Despite these notable advances, the residual presence of scattered birds and new nesting events show that total eradication requires continued targeted and coordinated efforts, and a renewed Action Plan for 2026–2030.

Monitoring and Evaluation Mechanisms

The Standing Committee of the Bern Convention receives annual national reports on the progress of eradication programmes. Expert meetings are regularly organized to share best practices, assess progress, and adjust strategies.

Conclusion

The fight against the ruddy duck illustrates the Bern Convention’s ability to unite European States around a common conservation goal and to coordinate effective cross-border actions. This work directly contributes to the protection of a threatened native species and the preservation of European biodiversity.