The conservation island effect of commercial hunting of red-legged partridges (Alectoris rufa) in agricultural landscapes

The global biodiversity crisis is driven by habitat changes to meet escalating food demands and is particularly evident in Mediterranean Europe through agricultural intensification and rural abandonment. Commercial hunting of red-legged partridge (Alectoris rufa) may benefit biodiversity where hunting estates manage for habitat quality. This approach, featuring food and water supplementation, legal predator control, and reduced hunting of European wild rabbit (Oryctolagus cuniculus), fosters favorable conditions for biodiversity conservation in agricultural landscapes. In a matrix of degraded terrestrial habitats, occasional large patches of natural habitat and better preserved traditional agricultural habitats can be seen as "conservation islands". We compared biodiversity and bird and mammal abundances in 10 commercial partridge hunting estates (treatment areas) with ten agriculture focused landscapes (controls) in central Spain. We detected 75 bird species, 63 in treatment and 52 in control areas. Transect surveys indicated higher bird species richness in treatment areas, alongside extended raptor sightings. Muscicapidae and Turdidae were more frequent in hunting estates, likely due to more natural habitat conditions. Additionally, wild rabbits were seven times more abundant in hunting estates, and the endangered Iberian lynx (Lynx pardinus) was exclusively detected in these. Non-target species, including rabbits (45%) and birds (21%), were attracted to partridge feeders and waterers. Our findings suggest that commercial partridge hunting lands enhance biodiversity by preserving habitat and supporting prey, potentially acting as conservation islands with positive effects on biodiversity beyond their borders.