Impact of wind farms on flying vertebrates: a systematic review for tropical and subtropical zones

Wind energy is a rapidly expanding renewable source, but it can threaten biodiversity, especially for flying vertebrates, such as birds and bats. In this systematic review, we analysed 40 scientific studies published between 2008 and 2023 to assess the impact of wind farms on birds and bats across tropical and subtropical zones, which are underrepresented in the scientific literature. Our results showed that Passeriformes (birds) and Vespertilionidae (bats) were the most affected groups, with collisions linked to flight height, and vegetation type. Despite their classification as Least Concern (LC) by the International Union for Conservation of Nature (IUCN), these groups exhibit vulnerabilities that require urgent attention. Resident species appear more affected. The review highlights critical gaps, including insufficient data on species affected, trophic guilds, vegetation characteristics at wind farm sites and surroundings, and species-specific flight behaviours. This study underscores the need for more comprehensive studies with robust monitoring protocols and the implementation of biome-specific mitigation strategies.