Wildfire Smoke Endangers North American Wild Birds
Wildfire smoke spreading hundreds of miles from distant burn sites is posing a direct threat to wild birds, according to researchers tracking air quality and avian health. As fire seasons start earlier, last later, and burn more land, scientists report that the massive geographical footprint of smoke events is confusing bird migration and forcing wildlife into new survival strategies.
Global Change Ecologist Launches Smoke Ecology Field
Olivia Sanderfoot, a global change ecologist at Cornell University, is spearheading a new field of study called smoke ecology to understand how wildfire smoke disturbs wild creatures and habitats. Sanderfoot’s interest began in 2018 while living in Seattle, where acrid air from Eastern Washington wildfires blanketed the city in a sickly yellow-gray haze. Two years later, recurring smoke caused burning eyes and prompted the researcher to investigate how animals cope with the toxic conditions. Sanderfoot noted that smoke acts as a toxic soup of substances that not only damages respiratory systems but also disrupts environmental cues birds use to find their way.
Physiological Vulnerabilities in Avian Respiratory Systems
Birds possess a specialized respiratory structure that makes them sensitive to airborne pollutants compared to humans. Human lungs rely on soft tissue for inhalation and exhalation, but birds have rigid lungs connected to a series of air sacs that function like bellows, maintaining a continuous flow of air. This system allows birds to take up about twice as much oxygen per breath as humans, which simultaneously exposes them to toxic particles and chemicals suspended in wildfire smoke.
Interdisciplinary Research Teams Track Air Quality and Movement
Understanding the impact of smoke requires collaboration across multiple academic disciplines, including conservation biology, statistics, ecophysiology, and atmospheric chemistry. Tracey Holloway, an atmospheric chemist at the University of Wisconsin-Madison and lead of NASA’s Health and Air Quality Applied Sciences Team, collaborates with Sanderfoot to track what moves through the air in three-dimensional space. Holloway explained that tracking exposure relies heavily on wind direction, chemical processes in the atmosphere, rainfall patterns, emission sources, air quality monitoring stations, satellite data, and computer modeling.
Volunteers Monitor Bluebird Boxes During Smoke Events
Because researchers cannot intentionally subject animals to wildfire smoke, scientists rely on widespread monitoring data. Pam Sowizral maintains nesting data by checking bluebird boxes three times a week during spring and summer. Sowizral and her volunteers recorded data before, during, and after smoke events drifted into the region from Canadian wildfires, providing researchers with measurements of bird activity and behavior.
Birds Use Three Strategies to Mitigate Smoke Exposure
Field observations analyzed by Sanderfoot indicate that birds react to smoke using three distinct strategies: hunkering down, flying away, or altering their behavior by reducing vocalizations and venturing out less often. These behavioral shifts serve as attempts to mitigate exposure.
Researchers Emphasize a Smokier Future for Wildlife
Sanderfoot aims to give people something they can do to help. With fire seasons starting earlier and lasting longer, researchers emphasize that the future will be smokier for both wildlife and human populations.
What Makes Birds Vulnerable to Smoke?
What specific breathing differences make birds more vulnerable to smoke than humans?
Birds have rigid lungs surrounded by air sacs that act like bellows, enabling a continuous flow of air that takes in roughly twice as much oxygen per breath as human lungs. This continuous airflow also increases their intake of toxic pollutants present in wildfire smoke.
How do researchers collect data on wildlife when smoke events are unpredictable?
Scientists rely on networks of people who collect ground-level data during routine monitoring programs, such as nest box checks conducted by Pam Sowizral.
What are the primary behavioral responses of birds during heavy smoke events?
According to research by Olivia Sanderfoot, birds respond to smoke by either hunkering down in place, evacuating the area, or shifting their behavior by reducing vocal activity and venturing out less frequently to forage.
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