Traffic in the sky: ranking the hazard bird species to aircraft-collision in Brazil

Birds pose a serious threat to aviation due to collisions, leading to both life and severe economic losses. To mitigate this problem and prevent further collisions, identifying the species with the highest aviation hazard should be the first step. Here we calculate a Relative Hazard Score (RHS) based on an extensive open-source database developed by CENIPA (Aircraft Accident Investigation and Prevention Center), which includes data on bird and mammal collisions between 2011 and 2022. We developed the ranking for (a) all vertebrate species, (b) all bird species, and (c) for bird families (including regional rankings); and for the second group, we investigated if there is a relationship between RHS, body mass, and group size. The black vulture ( Coragyps atratus ) appeared as the most dangerous animal for aviation, followed by dogs (including both domestic and wild), magnificent frigatebirds ( Fregata magnificens ), and unidentified vultures. According to our predictions, RHS presented a positive relation with body mass and group size. We reinforce the importance of this ranking for aerodrome management, which if added to more detailed information can be successfully used to decrease collisions. We appointed the most dangerous species in Brazil and, at the regional scale, to its biome, providing needed information to base actions to reach safer aviation in the country and similar regions.