2.5 Resistance surfaces
We extracted information from the nine background layers and produced resistance surfaces. We used 1 km grid to mask the study area, and every single grid (1 km) of the nine background layers was assigned a resistance value ranging from 1 (minimum movement resistance) to 100 (maximum movement resistance) representing the opposition of the selected layers to North China leopard movement according to expert opinions (Table S1). Each background layer was asked to assign a weight to define the final resistance surface, with weight values ranging from 0 (the layer has no impact on movement decision) to 10 (the layer is very important for movement decision). Then, we transformed the background layers to resistance layers according to the resistance values, and its corresponding weight. Therefore, the final two resistance surface layers (in 1990 and 2020) were created, indicating the impacts of all background layers on North China leopard movement (Fig. S2).