Relationship between environmental factors and den
characteristics
In a PCA of these data, principal component (PC) 1 and PC 2 explained
89.11% of the total variation in the environmental characteristics
(axis 1 = 76.73%, axis 2 = 12.38%). Terrain had a substantial
influence on den density, orientation, and entrance size and on the
angle of the den entrance. In addition, species richness had a
substantial impact on path density and tunnel volume (Fig. 10).