Modeling the probability of occurrence of red kites and black storks

As part of public contract O3.02.03-24-2282, lot 1, in partnership with Natagora, we developed a spatial model of the probability of occurrenceof red kites and black storks across Wallonia. We did this by gathering two distinct types of data for each species from various data holders: opportunistic data indicating potential territory and nesting data.

For each species, this data was validated and processed.  Nearly 24 environmental variables of different types and sources were filtered and analyzed at a resolution of 250 m² for each of these two datasets for both species through correlation analysis and Random Forest modeling.

Based on the selected variables, spatial models were constructed through 30 iterations of a tidySDM. This approach allows for the compilation of 4 spatial models—each weighted according to their quality—into a single set. The relative importance of each variable is then determined, allowing for the visualization of the probability distribution of the two species’ presence across Wallonia. The results are subsequently smoothed to produce homogeneous envelopes, illustrating the current core areas and the species’ range expansion in Wallonia, as well as areas of interest for the under-surveyed species, thereby addressing market needs.