Researchers are establishing a new field of study termed "smoke ecology" to examine how wildfire smoke impacts the health and behavior of birds and other wildlife. Scientists including Olivia Sanderfoot of Cornell University, Morgan Tingley of UCLA, and Tracey Holloway of the University of Wisconsin-Madison are collaborating to determine how species respond to toxic air that can travel thousands of miles from active burn sites. The research aims to identify conservation strategies, such as the creation of "smoke refugia," where animals can find water and shelter during heavy smoke events.
Birds are particularly vulnerable to air pollution due to their unique respiratory systems. Unlike human lungs that expand and contract, birds possess rigid lungs and a system of air sacs that act as bellows, providing a continuous flow of air. While this allows birds to extract nearly twice as much oxygen per breath as humans to sustain flight, it also makes them more vulnerable to toxic gases and fine particulate matter. Furthermore, birds lack many of the biological mechanisms mammals use to clear particulates from their airways.
Findings by Sanderfoot suggest birds employ three primary strategies when smoke arrives: hunkering down, flying away, or shifting behavior by vocalizing less or venturing out less frequently. A recent study indicated that repeated smoke exposure can impair body condition, leading to lower overall weight in various species. In 2020, researchers at the University of Oklahoma identified a correlation between toxic air from the August Complex fire—the largest in California history—and a "mass mortality event" involving tropical songbirds during their fall migration.
This research affects bird populations across North America, ranging from common backyard species like goldfinches to Species of Special Concern like Tule Greater White-fronted Geese. Data from the U.S. Geological Survey (USGS) showed that during the 2020 wildfire season, four tracked geese were forced to fly 470 miles further than usual and take twice as long to migrate to avoid thick smoke. For birds, these disruptions cause an "energy deficit," which can lead to death or lower reproduction rates because the animals lack the calories required for the journey or for fighting off infection.
The impact extends to human observation and conservation efforts involving thousands of volunteer citizen scientists. Data from the eBird and iNaturalist apps show that smoke changes how people see and hear wildlife; while reported sightings for many species decrease when air is smokiest, they increase for others that may be forced to forage closer to human homes. This suggests that during smoke events, birds may become more dependent on resources such as bird baths and feeders. Scientists believe that by understanding these patterns, they can better advise public policymakers on how to protect biodiversity as wildfire seasons burn more land.
Next steps for the research include continued monitoring through "Project Phoenix," a community science collaboration between the Natural History Museum of Los Angeles County and the La Kretz Center for California Conservation Science. Volunteers are being asked to conduct weekly 10-minute counts of birds. The gathered data will be used to test hypotheses regarding whether supplemental food and water help species persist during smoky periods. Future research will also utilize satellite data and atmospheric modeling to better predict how smoke moves through three-dimensional space and affects different habitats.