The release of common pheasants and grey partridges for bird dog training – consequences for biodiversity, animal welfare - and health.
Report no: 2022:32
The release of pheasants and partridges into Norwegian nature entails risks to biodiversity, animal health and animal welfare.
Thus concludes VKM in a risk assessment commissioned by the Norwegian Environment Agency and the Norwegian Food Safety Authority.
Pheasants and partridges have been released into Norwegian nature since the late 1800s. The birds are used to train bird dogs for hunting. Import, hold and release have not been regulated to much extent. The Norwegian Food Safety Authority and the Norwegian Environment Agency requested an assessment of the consequences that import, hold and release of the birds might have for biodiversity, animal health and animal welfare, and for risk mitigation measures.
The risk assessment is based on results from systematic literature searches, and observational data of pheasants and partridges in Norway from 2000 to 2022. In the absence of studies in Norway, VKM used information from other countries that release pheasants and partridges. VKM estimated that annually in Norway a few thousand birds are released.
VKM has assessed the consequences the release of the birds may have, regarding competition with Norwegian birds, crossbreeding with related species, transmission of disease, and on flora and fauna in the release areas. VKM has also assessed indirect consequences for other species and assessed effects on biodiversity with a 50-year perspective.
In addition, VKM has assessed how keep, transport, release and exposure to hunting dogs affects the birds’ welfare.
Results and conclusions
"Our assessments showed the release of pheasants and partridges poses a risk to biodiversity and to the health and welfare of the birds," said Eli K. Rueness, scientific director of the project.
The risk of negative ecological consequences may be particularly great for vulnerable species found in areas where pheasants and partridges are released.
"This applies, among other things, to yellowhammer that are classified as vulnerable on the Norwegian Red List. The population is in decline due to poor access to food in winter,” Rueness said.
The assessment showed that there is a moderate risk that exposure may have negative effects on flora and invertebrates.
Indirectly, activities related to the release of pheasants and partridges can lead to a moderate risk of changes in the incidence of predators. They can also affect competition between species because of elevated levels of pathogens (organisms which cause illness).
When it comes to animal health and animal welfare, VKM concludes that for extremely contagious diseases there may be a high risk of transmission of disease to wild bird populations. These diseases can spread between flocks of pheasants and partridges, especially with repeated contact.
“Our conclusion is that import and release increases the risk of the introduction and spread of bird flu and Newcastle disease in Norway. The risk increases with the number of birds being released,” Rueness explained.
According to the assessment, all factors associated with release are a burden to the welfare of pheasants and partridges.