Predation dynamics and breeding parameters of Mediterranean Short-toed Lark Alaudala rufescens and Thekla’s Lark Galerida theklae nests in western Catalonia

Agricultural intensification and changes in land use leading to habitat fragmentation are the main threats to steppe birds. Understanding nest predation and the factors driving it are essential tasks in the conservation and management of steppe bird species. This study investigates nest predation dynamics, hatching success, productivity and nest survival in two steppe-specialist lark species, the Mediterranean Short-toed Lark Alaudala rufescens and Thekla’s Lark Galerida theklae, in Catalonia (NE Spain). We monitored 13 nests over a 7-week period and found that 80% of Mediterranean Short-toed Lark nests and 25% of Thekla's Lark nests fledged successfully. Predation during the nestling stage accounted for all detected nest failures, with predators including snakes, foxes and birds. Although predated nests were found below taller plants than successful nests, the vegetation composition in the area surrounding nests did not differ significantly between predated and successful nests. This study underscores the critical role of predation in the reproductive success of ground-nesting birds and highlights the key role played by habitat management practices that help sustain a short, open steppe vegetation structure favourable to these species. The effective conservation of steppe birds requires a detailed understanding of predation pressures and habitat preferences, which will improve their breeding success and prevent further population declines.