In a new report, researchers say that wild boar in Norway have a varied and plant-based menu in autumn and winter. Truffles are one of the favourites.
The diet provides important knowledge about the wild boar’s ability to survive in Norway. Especially in winter.
The authorities want to eradicate the species in Norway
Recently, the wild boar re-established itself in this country. The animal is considered a foreign species due to its origin from the re-established Swedish population.
The species is controversial, both because it can damage inland and can transmit parasites and serious animal diseases such as African swine fever (ASF).
At the same time, it is a valued resource among many hunters. The consequences that accompany an outbreak of ASP make the wild boar inedible for the authorities. They have a goal that the species should be eradicated in Norway.
Monitoring increases knowledge
– In order to achieve the management goal, monitoring is necessary. This way we can gain increased knowledge about the wild boar’s distribution, sub-populations, use of areas and diet, says assistant research manager Jørgen Rosvold at the Norwegian Institute for Natural Research (NINA).
He says that this is also important information to be able to define the areas where measures are to be put in place in the event of an outbreak of African swine fever.
Researchers at NINA are in the process of building up an effective system to monitor the wild boar population in Norway.
In the new report, the researchers present results from three projects. They are about the wild boar’s distribution, use of areas and movement patterns, and what they eat. Together, the projects will strengthen surveillance and increase preparedness against African swine fever.
Males take greater risks
Samples of dung from 50 wild boars show that truffles make up a significant part of the wild boar’s diet in Norway. This especially applies in autumn and parts of winter. The diet was otherwise varied with different plant species. Birch, cypress, sunflower and barley were among the most common.
The researchers found few traces that the wild boar had eaten other animals in autumn and winter. They found only a few traces of earthworms, snails and insects.
Large, adult males ate 50 per cent more of wheat, barley and potatoes than females and small males. These are agricultural products that they may have found in the fields or on feeding grounds.
The difference between males and females may be due to the males being more willing to take risks. To a greater extent, they dare to move in areas with more human activity in order to obtain food with a high nutritional content.
– Studies of the wild boar’s diet are, among other things, important for understanding how the wild boar fares in Norwegian winter conditions. We would also like to carry out analyzes of the diet throughout the winter and not least in the summer when they are expected to use agricultural areas to a greater extent, says researcher Christer Moe Rolandsen at NINA.
GPS tagged five animals
The pilot project on GPS tagging of five wild boars has given the researchers the necessary experience on catching and tagging wild boars in Norway. It provides a good starting point for more extensive projects.
The GPS marking provides important data. They can be used to answer a number of issues in management and in general about the ecology of animals this far north. Not least, it is important for good preparedness against and combating African swine fever.
The wild boars in the project moved over relatively large areas and spent more time in the inland throughout the autumn. They could move long distances during the day. The movement pattern made it possible to discover how some of the animals dispersed and reproduced.
– There is a need for further research into wild boar’s use of areas in Norway. The animals here live under different climatic and topographical conditions than most other areas in Europe. In addition, the population density is lower. It affects the use of the area, says researcher Inger Maren Rivrud at NINA.
When animals are few, they often use larger areas.
Stays in the same areas
Observations of wild boar after March 2023 indicate that the species has not expanded its habitat on the Norwegian side in recent years. Clearly fewer animals have been observed in the former Hedmark county, while observations are stable in Akershus and Østfold.
Overall, this suggests that fewer wild boars stay outside the core distribution in Østfold.
The results so far are interesting to compare with what we know from the wild boar in Norway in prehistoric times. Then the distribution was limited to the rich deciduous forests along the coast up to the Sognefjord. There they had access to more oak and hazelnuts than they have today.
The animals disappeared when agriculture spread. Today, however, we see a different situation where a mosaic of forest and agricultural areas can provide good conditions for wild boar in other parts of the country than before.
Reference:
Inger Maren Rivrud, Christer Moe Rolandsen, Jørgen Rosvold et al.: Wild boar in Norway. Population monitoring: Distribution, area use and diet. NINA Report; 24512024.
