A Regional Habitat Suitability Assessment for Large Carnivores Across the Alpine-Dinaric‑Pindos Region

Large carnivore conservation requires harmonized, transboundary habitat assessments based on robust spatial data. We developed a multi-species habitat suitability modeling framework covering Southeast and Central Europe, including Greece, Albania, North Macedonia, Kosovo, Serbia, Montenegro, Bosnia and Herzegovina, Croatia, Slovenia, and Northern Italy (Alpine NUTS-2 regions). Occurrence data were compiled from many organisations from the above-mentioned countries and standardized into two datasets: systematic and opportunistic C1/C2 records and telemetry data for brown bear (Ursus arctos), grey wolf (Canis lupus), and Eurasian lynx (Lynx lynx, including L. l. balcanicus). More than 20,000 C1/C2 records were harmonized into a unified spatial database. Telemetry data (>700,000 locations) were spatio-temporally thinned to reduce autocorrelation, resulting in ~160,000 independent points. To address temporal mismatches between species presence and environmental data inherent in static modeling, we implemented a spatiotemporal feature extraction workflow for different topographic, land-cover, climatic and anthropogenic factors. With that, environmental data were dynamically matched to the year of species observation. Species-specific and combined habitat suitability models were fitted using Maxent and achieved high predictive performance (Boyce Index: 0.95–0.99; AUC: 0.89–0.95). The combined model demonstrated excellent validation (Boyce Index = 0.989), identifying the Alps, Dinarides, and Pindos mountain ranges as key regional strongholds. Moving beyond static suitability, we assessed functional connectivity using Omniscape (Omnidirectional Circuitscape). Habitat suitability was transformed into resistance via a negative exponential function to simulate landscape conductance. The resulting current flow maps highlight critical ”pinch points”; and transboundary corridors essential for maintaining gene flow. These results provide a robust, dynamic foundation for habitat conservation during spatial planning and green infrastructure development across the Adriatic-Ionian region.