Apostatic or Anti-apostatic? Prey Selection of Wolf Canis lupus L.(Mammalia: Canidae) in the Osogovo Mountain, Bulgaria

摘要: In a study conducted in 2018-2020, we tested the hypothesis that the wolf in Osogovo Mtn was selecting its prey opportunistically, with a preference for the most abundant prey (apostatic selection). To achieve this, scat analysis was performed simultaneously with prey density assessment through objective camera traps data, Random Encounter Model (REM) and selectivity analysis. The results showed that the wild boar was the most preferred prey by the wolf, complemented by the domestic horse. The roe deer had a smaller, close to insignificant share. The selectivity index also confirmed the wild boar dominance in the wolf diet, which was consistent through the years and seasons. The active selection towards wild boar was anti-apostatic in nature as the wild boar densities were 10-times lower than those of the roe deer. Our results differed from those obtained by a previous study in the same region in 2002–2003, where the roe deer accounted for 71.9% of the wolf diet. This study also showed anti-apostatic selection towards smaller prey probably formed by the decrease of the wild boar abundance in the past.