Biomass burning in the Neotropics is exposing migrating birds to elevated fine particulate matter concentrations

Aim: A unique risk faced by nocturnally migrating birds is the disorienting influence of artificial light at night (ALAN). ALAN originates from anthropogenic activities that can generate other forms of environmental pollution, including the emission of fine particulate matter (PM2.5). PM2.5 concentrations can display strong seasonal variation originating from natural and anthropogenic processes. How these processes affect seasonal associations with ALAN and PM2.5 for nocturnally migrating birds has not been documented.
Location: Western Hemisphere
Time period: 2021
Major taxa studied: Nocturnally migrating passerine (NMP) bird species
Methods: We combined monthly estimates of PM2.5 and ALAN with weekly estimates of relative abundance for 164 NMP species within the Western Hemisphere derived using bird observations from eBird. We identify groups of species with shared associations with PM2.5.
Results: PM2.5 was lowest in North America, especially at higher latitudes during the boreal win...