Inconsistent scientific methods hamper the management of drone use near birds

Abstract

Drone use has increased in the last decade, prompting efforts to manage their operation near wildlife. These efforts are hampered by variations in methods among studies, leading to evidence that is fragmented, inconsistent, and incomplete. To address this, we extracted evidence from 194 studies involving drones and birds, covering 314 species, including 61 studies on drone-induced bird disturbance that encompassed 206 species. We summarized the results of these 61 studies, identified evidence gaps, and developed a standard method for characterizing drone-induced bird disturbance. Drone-induced bird disturbance varied with species, breeding status, and distance of the drone from the birds. Key evidence gaps include a lack of studies on small terrestrial species likely to occur in urban environments where drones are often used and limited research in Africa, Asia, and South America. Methods were inconsistent among studies, with only 20% of studies reporting the often-recommended response variable of flight initiation distance (FID). We conclude that 1) managers should use evidence, including our database, to inform regulations, such as buffer distances, that account for species, breeding status, and drone type, 2) researchers should target contexts where interactions between drones and birds are likely but few studies exist, such as urban environments, and 3) researchers investigating drone-induced bird disturbance should conduct horizontal and vertical approaches directly towards birds, and record the FID along with predictors describing the environment, target, and stimulus.