Epsilon Archive for Student Projects

Abstract

Wildlife species are managed on a regional scale in Sweden and moose (Alces alces) are managed according to local moose population goals within moose management areas (MMA). The moose is the most important game species for hunters in Sweden. The grey wolf (Canis lupus) is a protected species but are managed through proactive culling to limit population size, where the aim is to kill all individuals in selected wolf territories. The aim of this study was to investigate if proactive culling of wolves’ result in 1) a decrease in the density of wolves, and 2) an increase in the hunter harvest and the density of moose in Sweden. Harvest statistics of moose (n = 84043) between the hunting seasons 2012/2013 and 2023/2024 from the MMAs (n = 19) within the counties Värmland, Örebro and Västmanland were used. The total harvest per MMA (per km2), the proportion of females out of adult harvest, and the proportion of calves out of the total harvest was analysed. The management goals of the moose population (decrease, no-change or increase), the esimated wolf territory density index, moose density before harvest, year, and treatment (culling or not) within the MMA (n=134) were used as explanatory variables. Two different time spans were analysed, a shorter (one year before and one year after culling of wolves) and a longer (three years before and three years after culling of wolves). There was a difference in wolf territory density before culling occurred between MMAs with culling (year 1: wolf index = 0.51) and the control areas (year 1: wolf index = 0.22). Wolf territory density decreased after culling, but the effect was weak (~8 %). For the total moose harvest, the short time span indicated no difference between areas, but for the longer time span, there was a time-lagged effect where in three years after wolf culling, the total harvest increased (14.3 %). None of the included explanatory factors explained variation in the proportion of females in the harvest. The proportion of harvested calves showed that culling of wolves had a negative effect on the harvest of moose, with a weak increase in the proportion harvested calves after the culling occurred. The results from this study is important knowledge for the adaptive management of carnivores and ungulates.