Figure 1. Distance-based redundancy analysis db (RDA) plot showing the resemblance between Helix pomatia subpopulations based on the average diet composition of snails in different subpopulations and at different dates. Subpopulations 1–8 are indicated by different colours and symbols. Vectors are fitted for the predictor variables selected in the distance-based linear model (black: Hgt.shl, average shell height, Hgt.veg, average feeding heigh; Wdt.shl, average width of shells; Smp.day, sample day). Diet resources (in red, with: Urt.dio, Urtica dioica; litter, plant litter) with multiple correlation coefficients> 0.3 are superimposed.