If we then compare the IUCN range maps to the MCPs (using the habitat-filtered maps, as these can be as small as 8% (B. dahlbomii, P. onca) of the largest MCPs), we find large areas of commission error (mapped areas that fall outside species actual ranges due to either wrong points, or unsuitable habitat within the MCP), highlighting that much of these areas are still unsuitable (Table 2). Whilst modelling could be used, and would further refine distributions (i.e. Hughes et al., 2021c), these steps highlight that even if data were adequately cleaned, the final outcomes would still not be indicative of species ranges; at a minimum, a habitat filter must be imposed, and coarser filters based on intactness can be easy to apply (e.g. Lu et al., 2021). Thus, whilst global prioritisation and ambitious analyses are needed, species-specific models or maps for many groups, such as insects, are simply not possible globally without additional efforts to collate data (Garcia-Rosello et al., 2023); such attempts would simply not be representative of data-poor regions, or indeed, any biodiversity hotspot (especially if no habitat filter was implemented). Until data-gaps are filled (as in the case of concerted work for ants: Kass et al., 2022), meaningful analysis will remain challenging or even impossible at global scales, and focusing on taxa or regions where such data are available is necessary.
Table 2. Overlap between IUCN ranges and habitat-filtered MCPs.