Protected areas provide incomplete coverage for wintering Red Kites (Milvus milvus) in European agricultural landscapes

Designation and management of protected areas (PAs) can mitigate detrimental anthropogenic impacts on biodiversity. Across Europe, an extensive network of PAs exist to protect wildlife and habitats. These sites aim to provide important refugia for species of conservation interest, which include the Red Kite (Milvus milvus; hereafter "kites"). Currently, kites are classified as globally Least Concern but in danger of extinction in parts of their range such as Spain. However, it remains unclear to what extent kite ranges overlap with PAs with fundamental knowledge gaps persisting for the species during winter. Using data for 103 kites tagged with GPS-GSM telemetry loggers over 180 winters between 2013-2022, we modelled proportional overlap between kite winter ranges and both European Natura 2000 sites and Important Bird and Biodiversity Areas (IBAs). We also explored the effects of various demographic, geographic and environmental predictors of PA overlap in tagged kites. Overall, 24.5 ± 28.1% (± SD) of kite winter core areas and 26.6 ± 20.5% of winter home ranges overlapped with European PAs. Kites that wintered in areas with greater agricultural land cover had lower overlap with PAs. Kites that wintered in Iberia (Spain and Portugal) and the Pyrenees (France and into northern Spain) had lower overlap with PAs than conspecifics wintering in Central Europe. Wildlife that rely on traditional agricultural landscapes during winter may thus remain unprotected by existing European PAs. Policymakers should consider the conservation needs of such species when designating new PAs, especially as Spain holds the largest global wintering kite population, and the species is categorised as "In danger of extinction" in the Spanish National Catalogue of Threatened Species. Improving protection of wintering kites in Iberia remains an urgent conservation priority.