Biological Hazards | Animal Health and Welfare | Biodiversity
Wild boar population in Norway – implications for health and environment
Report no: 2018: 14
The wild boar population in Norway is likely to increase and spread to new areas unless drastic measures are enforced.
That is the conclusion of the Norwegian Scientific Committee for Food and Environment (VKM) after having assessed the possible implications for biodiversity and animal- and human health, should the wild boar population establish in Norway.
From 1000 to 40,000 animals
Wild boar is considered an alien organism in Norway and assessed to have a potentially high impact on biodiversity. Today there is about 1,000 animals in Norway, primarily in Østfold county.
According to the calculations made by the VKM, there is sufficient space and suitable habitat to sustain 220,000 animals under current climate conditions. It is primarily the lowland areas and costal regions from Sweden to Trøndelag which is best suited for wild boar.
"We can assume that the population will double every third year. Taking topography and habitat into account, it is realistic to assume that the population will grow to about 40,000 individuals, rather than 220,000, within the next 12-15 years," says Eystein Skjerve, who has led the scientific project team.
In a 50-year perspective, as we expect a warmer and more humid climate, the population is likely to increase even more rapidly.
Impact on ecology and agriculture
Wild boar root in meadows and dig up freshly sown crops and vegetables. This can be detrimental to endangered plant species, and very costly for farmers. However, several studies have shown that rooting can also have a positive effect on the biodiversity. The lack of long term studies makes it difficult to estimate the scope of the ecological consequences that an increased wild boar population in Norway will have.
Impact on animal health
VKM has identified several agents that can be transmitted to domestic pigs. These include serious viral diseases like the African Swine Fewer, Classical Swine Fewer and Foot and mouth disease.
"The probability of direct transmission from wild boar to farmed pigs is high if farmed pigs are kept in outdoor facilities. This either can happen through live wild boar bringing the disease through Sweden, or from imported swine products," says Skjerve.
Additionally, the level of Salmonella, Trichinella and Toxoplasma gondii is likely to increase. This would result in a higher risk of transmittance to humans.
The impact of humans
The spread and establishment of wild boar to new areas is often linked to human activity. This includes translocation of animals and supplement feeding, in order to establish the species as game.
"To what degree these activities are practiced in Norway will be decisive for how the distribution and local population densities will develop. Unless drastic measures (culling, ban on feeding, etc.) are enforced within the next few years, the wild boar population will most probably grow significantly and spread to new areas in Norway," says Skjerve.
Additionally, a warmer and more humid climate, as predicted for the next 50 years will benefit the wild boar population, as we expect higher winter survival rates and more habitat to become suitable.
VKM's Scientific Panel on Biological Hazards, Panel on Alien Organisms and trade in Endangered Species (CITES) and Panel on Animal Health and Welfare are responsible for the assessment.