News
Continued vigilance needed for bird flu in wild birds
After a relatively quiet spring, with few reports of avian influenza among wild birds in the Netherlands, recent developments are raising new concerns. While the highly pathogenic H5N1 virus never fully disappeared, the increased mortality seen in previous breeding seasons was notably absent, particularly among colony-nesting gulls and terns. However, since the end of May, several bird flu cases have been reported in specific areas. These developments underscore the importance of continued vigilance throughout the summer months.
The monitoring of avian influenza in wild birds is a collaborative effort involving several organizations. Testing of live, captured birds is primarily carried out by Erasmus MC, while Wageningen Bioveterinary Research (WBVR) is responsible for examining dead birds. Field observations from bird ringers and researchers, site managers, and a wide network of alert observers play a vital role in signaling new outbreaks and incidences.
Recent cases
In recent weeks, most reports have come from the province of Zeeland. At Noordervroon near Westkapelle, staff from Deltamilieu Projecten found and removed at least 85 dead birds, mainly juvenile Herring Gulls, along with several Common Terns, a Pied Avocet, a Sandwich Tern and a Black-headed Gull. Twelve birds were tested, and all were found to be positive for the highly pathogenic H5N1 virus. Additional positive test results have come from other parts of Zeeland, including Vlissingen, Domburg and Koudekerke, where dead Herring Gulls and a Northern Gannet were sampled. In North Holland, a live Buzzard tested positive as well. Reports of increased mortality have also come in from the gull colony on Slijkplaat in the Haringvliet and from IJmuiden. Test results for those locations are still pending.
A monthly update of bird flu test results is available on the DWHC website.
Reporting remains essential
Nearly a year ago, the LiveAtlas-project was launched to systematically collect more data on bird mortality. These counts are essential to improve our understanding of mortality peaks and their impact on bird populations. Participants are encouraged to continue logging their observations.
Individual reports of dead birds can still be submitted via platforms such as DWHC and Sovon. These platforms also allow you to indicate whether a dead bird is available for testing. If so, DWHC will contact the person reporting the case.
If you come across a dead bird that needs to be removed, please contact the local site manager or municipality.
Handle with care
Avian influenza is a zoonotic disease, which means it can potentially be transmitted from animals to humans. Caution is therefore essential when encountering sick or dead wild birds. Always follow hygiene protocols and avoid handling birds with bare hands. If you wish to have a dead bird collected for testing, make sure it is double-bagged in plastic without direct contact.
For more detailed guidance, consult the government’s manual: Guidelines for handling wild birds with avian influenza (in Dutch only).
