Assessing species' risk of extinction for conservation actions usually involves a range of metrics based on the distribution of the species. Species distribution modelling is a common approach used to predict the extent of suitable habitat, however, such models may rely on idiosyncratic decisions and be challenging to implement for multiple species.
In this study, authors developed a simple five-step geospatial workflow relying on a user-friendly and deterministic method called inverse distance weighting (IDW) to map the area of habitat (AOH) within a species' range—suitable for conservation planning and decision-making.
Using GBIF-mediated occurrences of forest birds from the Americas, the authors chose 723 species as their case study to evaluate the performance of the IDW workflow. They used the occurrence data to draw and define the extent of occurrence (EOO) of each species and derived absences from eBird hotspots in which a species was never recorded.
When compared to expert-drawn maps from BirdLife, the IDW workflow produced maps of 40 per cent higher accuracy with substantially fewer errors of both omission and commission. While the authors found no significant difference in the size of ranges, AOH values from expert-drawn maps were consistently smaller than IDW-derived estimates.
With a lower technical threshold than species distribution modelling and an overall improved accuracy over expert-drawn maps, the authors argued that the reproducible IDW workflow may be used reliably for identifying critical areas for conservation actions and establishing protected areas.