Species distribution models are used to predict where different types of species might live based on environmental conditions. To make these models accurate, a certain number of specimen records are needed. A study focused on the Caatinga biome in Brazil found that for species with narrow distributions, at least 17 records are needed, while for species with widespread distributions, at least 30 records are required. This helps ensure that the models accurately reflect where these species are likely to be found in the Caatinga biome.