Nest selection and usage of nest boxes by the Sooty Falcon <i>(Falco concolor)</i> in the Al Wajh Bank (Saudi Arabia)

Abstract Artificial nesting sites, commonly called “nest boxes” for their shape, are used to increase animal nesting site availability in highly modified or degraded habitats, such as urban or agricultural areas, or at natural sites where nesting habitat is scarce. They are beneficial for many bird species as they provide suitable breeding sites. The objective of this study was to assess the nesting habitat preferences of the Sooty Falcon breeding in the Al Wajh Bank and to create and test different types of artificial nesting sites for this species on the field. The prototype selected was replicated and deployed in low numbers across seven islands to test the response of the species to this new nesting site. Since the prototype was successfully occupied by Sooty Falcons, the pilot study was considered successful and upscaled to 15 islands the following year. During the pilot and subsequentially on the first year of the upscale, two nest boxes were successfully occupied by breeding Sooty Falcons, making the first time in literature that this species utilizes an artificial nesting site as breeding site. This is a milestone in the Sooty Falcon conservation worldwide and will help expanding nesting habitat in degraded or nesting habitat lacking islands. This study demonstrates the potential for artificial nesting sites to enhance breeding habitats for the vulnerable Sooty Falcon. While initial occupancy rates are low, the successful fledging of nestlings in 2023 and 2024 suggests long-term promise. Continued monitoring and research are essential to refine deployment strategies and support conservation efforts for this iconic species.