Home ranges and movement patterns of wild boars (Sus scrofa) at the northern edge of the species’ distribution range

Abstract

In Finland, the wild boar (Sus scrofa L.) lives on the northernmost edge of the species’ distribution range, and the population mainly originates from individuals immigrating from Russia. Most of the current population lives in the southeastern part of the country, and the wild boar is steadily expanding further. To develop effective risk and population management in novel northern wild boar regions, detailed information about the species’ local ecology is required. To estimate wild boar movement patterns, 17 adult wild boars were monitored using GPS collars from May 2020 to September 2022 in the core region of the current distribution. The average total home ranges of wild boars (87.1 ± 17 km2 MCP, 33 ± 5.5 SE km2 95% KDE) were larger compared with studies from southern latitudes. The length of nocturnal activity times varied seasonally. All studied individuals at the border zone (N = 15) showed continuous transboundary movements, with home range core areas located mainly on the Russian side. Wild boar locations were predominantly in the Russia border zone, especially resting sites during the daytime. Most locations in Finland were from night-time feeding excursions. Our study shows that, although home ranges are large, adult wild boars are relatively sedentary also in northern latitudes. However, the movement capacity of the species enables the transboundary spread of diseases such as African swine fever. Our results provide information for risk management and emphasize the importance of transboundary collaboration in the monitoring and management of common wild boar populations.