Fig. 5

Distribution of the number of included studies in the six specific questions (from Q1 to Q6, see Table 1), five types of LTIs (roads, waterways, powerlines, railways, and pipelines), and six biological groups (birds, small mammals, bats, other mammals, amphibians, and reptiles). Square size indicates the proportion of studies in each combination of a questions and biological groups, b questions and LTIs, c LTIs and biological groups, and d LTIs and biological groups for the specific question Q2 (role of habitat of verges)