Assemblages of orthopterans, small mammals and birds of prey in areas after conversion from arable land to grassland

Intensive agricultural management is considered a factor contributing to biodiversity loss, and therefore, there are increasing efforts to convert areas of arable land into extensively used habitats. Our study describes the colonisation process of Orthoptera, Mantodea, and small mammals on land converted to managed permanent grassland, while also assessing the impact on birds of prey abundance. Research conducted between 2021 and 2024 indicated rapid positive responses by the studied taxa, with Site 1 recording 16 Orthoptera and Mantodea and 12 small mammal species, comparable to other natural sites in the Danube Lowlands. No differences were found in Orthoptera abundance and species richness, or small-mammal abundance; however, small-mammal species richness was higher at Site 1. The abundance and species richness of small mammals at both sites exhibited pronounced seasonal variation, peaking in autumn. We found a positive relationship between the abundance of small mammals and the abundance of birds of prey. The birds of prey assemblage was dominated by common buzzard (Buteo buteo), common kestrel (Falco tinnunculus), and western marsh harrier (Circus aeruginosus). Our research underscores the swift adaptability and colonisation capabilities of the studied taxa and suggests that recently converted grasslands can support relatively diverse assemblages of orthopterans, mantids, and small mammals within a few years of conversion. Consequently, these restored habitats provide a critical food supply for birds of prey, mitigating declines in prey abundance caused by intensive agricultural practices in the surrounding landscape.