Succesfully managing the raccoon dog to reduce risks to biodiversity and health

Could you provide a brief overview of your project – what are the main objectives and expected outcomes?

"I am the scientific project leader of an adaptive management project aiming to eradicate invasive alien mammals, birds, reptiles and amphibians in Sweden. The project is responsible for all EU-listed animal IAS (Invasive Alien Species) on land and some additional prioritized species that are considered invasive in Sweden, such as the marsh frog, the stone marten and some targeted efforts against the American mink." 

"The project is led by the Swedish Association for Hunting and Wildlife Management and funded by a framework contract from the Swedish Environmental Protection Agency. SLU is a partner in the project and responsible for the monitoring and applied science in the project, securing efficiency in methods as well as humane management of the animals."

"The project started with the raccoon dog in northern Sweden in 2008 and today covers eleven species all over the country. The work has been very successful, all species are decreasing or kept at very low levels. Some, like the raccoon dog, are today almost extinct. Twenty new raccoon dogs were disclosed and captured or culled in 2024. If the management had not started in 2008, we would now, according to our models, have had over 10 000, probably 20 000, raccoon dogs in northern Sweden and on the move south.”

How does the research relate to the One Health concept?

“Invasive alien animals can spread very fast. Birds can fly long stretches and some mammals, like the raccoon dog, can move 300 kilometers in a few weeks.”

“Successful IAS are, almost by default, very adaptable, otherwise they would not succeed in new areas. They can thrive in new areas, and some can also host a variety of different diseases and parasites. The raccoon dog which is native to east Asia was moved to western Soviet Union in the 1930-1940s. When rabies spread from Russia to Finland in the late 1980s, 73 percent of the cases were found in raccoon dogs!” 

“It is also shown that the raccoon dog can be very efficient in spreading the fox tapeworm, which has recently been detected in a few local areas in southern and mid Sweden. It is not necessarily the raccoon dog that will bring new diseases to the country, but it’s extremely high population densities, if allowed to establish, and the species’ social nature will increase the infection pressure in nature.”

What do you consider the key challenges and opportunities in your research area concerning biodiversity and health?

“Invasive alien species are generally bad for biodiversity. They occupy areas and either outcompete or kill native species. Invasive alien animals may spread diseases to native species."

“The most cost-efficient way to manage invasive alien species is to prevent them from ever coming to the country. This is for example what Norway is doing with the raccoon dog, they finance the management in northern Finland and support the Swedish management when needed, to stop the raccoon dog from entering Norway. The cost for doing this is just a fraction of what it would be if the raccoon dog were to establish in Norway.“ 

“The next best thing is early detection and rapid response. That is essentially what our project has been about since 2008, to through applied research improve and apply new methods in the ongoing management. Examples of successful progress are our sterilized Judas raccoon dogs that are exposing wild raccoon dogs to us, and our citizen science system that has led to over 70 percent of all our captured or culled raccoon dogs.“ 

“In general, the largest challenge with IAS in an international perspective is reasonable funding to be able to manage effectively, and access to private land. Both criteria’s are fulfilled in Sweden regarding the invasive alien animals on land, that we work with, but are seldom so in other countries.“

Photo: Ryzhkov Sergey, CC BY-SA 4.0, via Wikimedia Commons