Associate Professor University of California, Los Angeles
For over a century, birds have served as valuable sentinel species for air pollution. From the canaries used by coal miners to monitor noxious gasses in the early 1900s, to the mass avian die-off in the Western U.S. following the catastrophic 2020 fire season, the fate of birds has foreshadowed our own vulnerability to air toxics. Yet, few studies have explicitly linked ambient air pollution to avian vital rates, population dynamics, or species distributions, precluding consideration of air pollution impacts when designing conservation plans for threatened species. Addressing these knowledge gaps is inherently challenging, as air pollution is highly variable in space and time; to capture the range of air quality conditions birds experience day-to-day requires far more extensive monitoring than is supported by traditional field surveys. Public participation in science has emerged as an exciting new tool to study avian responses to air pollution. By engaging volunteers in data collection, ornithologists can survey birds at regional scales that were once impossible, thereby facilitating studies of avian responses to highly localized and rapid environmental change, such as day-to-day shifts in air pollution. Here, we use eBird – a global, semi-structured citizen science program – to link air pollution to the detectability and occurrence of backyard birds in the American West during the 2015–2020 wildfire seasons. We integrate observations from eBird with robust estimates of wildfire-specific fine particulate matter in a dynamic occupancy framework to quantify the effect of smoke on the site use, colonization, and emigration of our study species. We relate these effects to strategies birds may use to cope with smoke exposure (e.g., stay, shift, leave). By comparing these strategies across species and functional traits, we aim to identify which species are likely most vulnerable to wildfire smoke.
