Data analysis
All statistical analyses were carried out in R version 3.6.1 (R-Core-Team, 2019). We standardized (scaled) all continuous covariates by subtracting the mean and dividing by one standard deviation. We used Pearson’s correlation tests to check for collinearity among continuous variables, with a limit of r ≤ 0.6 (Zuur et al., 2010).
We used structural equation modeling (SEM) to test how interactions among mesopredators (red fox, badger and pine marten) were affected by large carnivores (wolf and lynx), land cover variables (proportion of agricultural land and EVI), and human disturbance, as well as how these interactions were affected by season (summer vs winter). SEM provides a multivariate framework to develop and evaluate hypothesized networks of causal relationships, estimating the relative strength of direct and indirect paths within the system (Grace, 2006, Grace et al., 2012).