Again many wild birds affected by bird flu
The current outbreak of the highly pathogenic H5N1 virus, which has caused increased bird mortality in the Netherlands since November, is spreading rapidly. Barnacle Geese in the Northern parts of the Netherlands in particular are greatly affected, but the virus has also been detected in other species and other areas. Vigilance is therefore required.
Current outbreak
The presence of bird flu among wild birds is currently most clearly visible in Barnacle Geese. As in 2020-2022, large numbers of dead specimens are being reported (sometimes several dozen per location) as well as sick birds with clear symptoms of bird flu. Especially in the Wadden area and elsewhere in the Northern and Western parts of the Netherlands. Greylag Goose and European Herring Gull also stand out due to a number of reports higher than average.
The table below shows the numbers of dead wild birds in which highly pathogenic avian influenza has been detected by the DWHC and Wageningen Bioveterinary Research (WBVR) since November 1st. In the majority of cases, it concerned the H5N1 variant of the virus. Only a Common Buzzard and a Black-headed Gull were infected with H5N5. The map showing the distribution of the cases from our previous post is regularly updated with the latest results.
| Positive | Negative | Still undergoing research | Total | |
| Barnacle Goose | 11 | 4 | 11 | 26 |
| Common Buzzard | 5 | 10 | 3 | 18 |
| Gerylag Goose | 21 | 10 | 0 | 31 |
| Great Black-backed Gull | 1 | 0 | 1 | 2 |
| Northern Goshawk | 1 | 1 | 0 | 2 |
| Pink-footed Goose | 1 | 0 | 0 | 1 |
| Mute Swan | 2 | 13 | 1 | 16 |
| Black-headed Gull | 1 | 8 | 0 | 9 |
| Greater White-fronted Goose | 4 | 3 | 1 | 8 |
| White Stork | 1 | 0 | 0 | 1 |
| Peregrine Falcon | 2 | 0 | 0 | 2 |
| Eurasian Wigeon | 1 | 3 | 0 | 4 |
| Feral Greylag Goose | 4 | 0 | 0 | 4 |
| Eurasian Sparrowhawk | 1 | 2 | 1 | 4 |
| Common Kestrel | 1 | 2 | 1 | 4 |
| Common Redshank | 1 | 0 | 0 | 1 |
| Eurasian Teal | 1 | 0 | 0 | 1 |
| Eurasian Curlew | 1 | 0 | 1 | 2 |
| European Herring Gull | 5 | 2 | 0 | 7 |
| Total | 65 | 58 | 20 | 143 |
Scavengers and predators are also at risk
By eating infected prey, species other than waterfowl can also get infected with the virus. For example, the current outbreak affects the vulnerable Peregrine Falcon, but other species such as Common Buzzard, Northern Goshawk, European Herring Gull and Great Black-backed Gull and various mammals are also at risk. Such as the fox displaying neurological symptoms that was found on the 11th of January in Hoofddorp, this animal tested positive for bird flu.
Keep reporting
Last autumn, Sovon started systematically collecting more data on bird mortality via the LiveAtlas project. These are needed to be able to make more accurate statements about the course and extent of mortality peaks and their impact on populations. Participants in the LiveAtlas project are therefore encouraged to continue their help.
In addition, reports of dead birds can be made via the form on our website and Sovon. If the dead animal is being offered to send in for research, we will contact the reporter directly.
DWHC does not clear away animals. To have dead animals cleaned up, you can contact the site manager or municipality.
Bird flu is a zoonosis (disease transmissible from animal to human). The DWHC therefore advises the public to be careful when approaching sick or dead wild birds and to adhere to hygiene measures. If you have found a dead animal that you want to have collected for research, it is important that the animal is double-wrapped in plastic, but never touched with bare hands. A guide on how to handle wild animals with bird flu can be found here: Guideline for dealing with wild animals with bird flu.
Roy Slaterus, Sovon Vogelonderzoek Nederland
Valentina Caliendo, Dutch Wildlife Health Centre
