How Smoke From Distant Fires Is Changing the Skies Over North America

Olivia Sanderfoot stands on a hillside near Amherst, Massachusetts, listening for birdsong. An Eastern Wood-Pewee, a goldfinch, a downy woodpecker — it is a morning full of life. But Sanderfoot knows the birds here do not always have it easy. Last summer, smoke from Canadian wildfires drifted over this spot, and she wants to know how the birds coped.

Sanderfoot is a global change ecologist at Cornell University. She is building a new field of study called “smoke ecology,” and her question is simple: how does wildfire smoke disturb wildlife, and can anything be done to stop the damage?

Smoke That Travels Thousands of Miles

Wildfires produce smoke that can drift hundreds to thousands of miles from the burn site. That means the footprint of a smoke event far exceeds the size of the fire itself. For birds, that means the air they breathe changes without warning, and no one knows exactly what happens next.

Sanderfoot felt the effects personally in 2018, when she lived in Seattle and wildfires burned in Eastern Washington. “The air smelled acrid,” she recalls. “The city was just blanketed in this sickly yellow, gray haze.” She was told it was a one-time event. It happened again two years later.

Why Birds Are Especially Vulnerable

Smoke is a mix of harmful chemicals, and birds breathe it in differently than humans do. Human lungs are soft and flexible, allowing air to move in and out easily. Bird lungs are rigid, surrounded by air sacs that act like bellows, pushing air continuously through the system.

“This allows birds to take up about twice as much oxygen with each breath that they inhale compared to us,” says Sanderfoot. “This means that they’re vulnerable to all the other things that are in the air, too.”

A Field Built From Many Disciplines

Sanderfoot’s research draws on conservation biology, statistics, ecophysiology, and atmospheric chemistry. She works with Tracey Holloway, an atmospheric chemist at the University of Wisconsin-Madison who leads NASA’s Health and Air Quality Applied Sciences Team.

“We need to be tackling new problems with new partnerships,” Holloway says. The science depends on air quality monitoring, satellite data, and sophisticated computer models. Researchers need to know what is moving through the air in time and three-dimensional space — wind direction, chemical processes, rainfall, and emission sources.

The Problem With Smoke

Smoke is hard to predict. It can arrive one day and vanish the next. That makes it difficult to study its effects. Scientists cannot control where smoke appears or when, and they prefer not to expose animals to smoke on purpose.

Morgan Tingley, an ecologist at UCLA, frames the challenge: “What we’re trying to do is get smoke to be recognized as a disturbance in and of itself distinct from fire that is worthy of our concentrated attention.” He has spent his career studying wildfires, which have clear starts and stops. Smoke presents its own set of problems, spreading far from the original blaze.

Citizen Scientists Watch the Birds

Sanderfoot relies on a network of amateur birders and professional conservationists across the country. They collect data when smoke blows in, and that information feeds into the broader picture of how birds respond.

Pam Sowizral is one of those volunteers. She runs the bird project at Mass Audubon’s Drumlin Farm Wildlife Sanctuary in Lincoln, outside Boston. On a sunny morning in late August, she walked up to a bluebird nest box and knocked gently on the outside.

“Always give a little knock first,” she advised quietly. When she lifted the side panel, she revealed two baby bluebirds huddled on a bed of pine needles. These were the last of the season.

Nearly every year for the last 20 years, Sowizral and her volunteers check the bird boxes three times a week in spring and summer. They count nests, eggs, and chicks.

What the Research Needs to Show

The field of smoke ecology is still young, and much remains unknown. Scientists are piecing together observations — the absence of birdsong, the sudden arrival of hungry birds in backyards — but they lack systematic data.

The researchers hope to build a clearer picture of how smoke moves through the air and how birds react to it. The ultimate goal is to protect wildlife from the growing threat of distant fires.

The work is slow, but the questions are urgent. Smoke travels fast, and so does the science.

Source material: “Wildfire smoke affects animals in unique ways. Scientists are trying to understand it,” NPR.

birds · climate change · environmental science · smoke ecology · wildfires