Abstract

Topic: Moose management and monitoring

Counteracting management of a transboundary moose population in Scandinavia

Barbara Zimmermann¹, Paige Hellbaum², Giorgia Ausilio³, Håkan Sand³, Camilla Wikenros³, Ane Eriksen⁴, Kristoffer Nordli⁴, Petter Wabakken⁴, Malin Aronsson³, Jens Persson⁵, Jonas Sveum⁴, Sara Skybak⁶, Maria Falkevik⁷, Anders Esselin⁸, Karen Marie Mathisen⁴

Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, University of Inland Norway, Elverum, Norway
GRID Arendal, Tyholmen, Norway
Department of Ecology, Grimsö Research Station, Swedish University of Agricultural Sciences, Riddarhyttan, Sweden
Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Campus Evenstad, University of Inland Norway, Koppang, Norway
Department of Ecology, Grimsö Research Station, Swedish University of Agricultural Science, Riddarhyttan, Sweden
Solør Highschool, Sønsterud, Gjesåsen, Norway
Värmland County Administrative Board, Karlstad, Sweden
Man and Nature, Sigtuna, Sweden

The management of migratory species is often challenged by an uneven distribution of wildlife benefits and costs, leading to local management decisions to maximise net-benefits instead of population-wide approaches. If the migration route involves several jurisdictions, management collaboration is even more complex, because monitoring and management systems may differ. Here, we studied a trans-boundary moose (Alces alces) population across the national border between Norway and Sweden from summer 2020 to autumn 2021. We assessed seasonal moose densities using fecal pellet group counts, measured browsing impacts on pine (Pinus sylvestris) by combining the official Swedish and the most used Norwegian browsing survey methods, and compiled harvest statistics. Moose were evenly distributed in the study area during summer, but concentrated in the southern parts of the study area during winter. The Norwegian browsing assessment method, i.e. the proportion of browsed pine shoots of the year, revealed that browsing pressure was low, allowing an increase in future moose abundance. Contrary, the Swedish method revealed that the browsing damage, i.e. the proportion of damaged pine stems, was mostly at a level that was critical to forestry, calling for an immediate reduction of the moose population. An analysis of the harvest statistics confirmed that the respective Norwegian and Swedish management bodies followed up these results by reducing harvest and saving adult females in Norway and increasing harvest and keeping the sex ratio in adult harvest close to 1:1 in Sweden. High harvest densities in Swedish local management units reduced winter moose densities locally, but the harvest rate (proportion of summer moose abundance harvested) had only a negative influence on browsing pressure and damage in Norway, not in Sweden. This is likely a result of the aggregation of moose in the Swedish moose management units. The two counteracting management regimes hinder each other’s regional objectives for both moose harvest and forestry. We propose the establishment of a forum where local stakeholders can collaborate across the border, the harmonization of monitoring methods, and ideally the establishment of transboundary moose management units.