Cornell Ecologist Aims to Define 'Smoke Ecology' as Wildfire Smoke Affects Birds

Sanderfoot stood on a flower-freckled hillside in Amherst in Western Massachusetts, listening to an Eastern Wood-Pewee, a goldfinch and a downy woodpecker. Birds foraged among the flowers, and fluffy fledglings darted about. But over the summer, the same area was suffused with toxic smoke from distant wildfires in Canada. Sanderfoot said smoke can blow hundreds to thousands of miles from a burn site, meaning the footprint of a smoke event greatly exceeds that of any fire. How birds deal with that is the question driving her work.

Her curiosity about how birds cope with smoke emerged in 2018, when she was living in Seattle and wildfires burned in Eastern Washington. She recalled that the air smelled acrid and the city was blanketed in a sickly yellow-gray haze. She was told it was a one-time event, but the same thing happened two years later. Walking outside, her eyes burned, and she wondered what animals were doing and whether they were OK. Apart from anecdotes such as the absence of birdsong or famished and parched birds arriving in backyards, little was known.

Sanderfoot describes smoke as a toxic soup of substances. The problem is not only what birds inhale, which she said is inevitably bad for them, but also how the cues birds use to navigate their world are upended when it gets smoky outside. To puzzle out what was going on, she realized she needed to collaborate with researchers from fields including conservation biology, statistics, ecophysiology and atmospheric chemistry.

Tracey Holloway, an atmospheric chemist at the University of Wisconsin-Madison, the lead of NASA's Health and Air Quality Applied Sciences Team and a colleague of Sanderfoot's, said real-world problems do not map cleanly onto academic silos set up for decades. 'We need to be tackling new problems with new partnerships,' Holloway said. Understanding what birds inhale requires knowing what is moving through the air in time and three-dimensional space, she said. That depends on wind direction, chemical processes in the air, rainfall patterns and where emissions come from. The science relies on air quality monitoring, satellite data and increasingly sophisticated computer modeling.

Birds are especially sensitive to smoke largely because of how they breathe. Humans have soft lungs that allow inhalation and exhalation of air. Birds have rigid lungs surrounded by a collection of air sacs that act like bellows, pushing air continuously through the system. Sanderfoot said this allows birds to take up about twice as much oxygen with each breath as humans do, which means they are vulnerable to other things in the air as well.

Morgan Tingley, an ecologist at UCLA and another member of the emerging smoke ecology group, said the goal is to get smoke recognized as a disturbance in and of itself, distinct from fire and worthy of concentrated attention. Much of his career has focused on wildfires, events with clear starts, stops and borders. Smoke from those fires can spread far from the original blaze, however. Tingley said smoke is extremely hard to predict and highly variable: it can be there one day or one hour and gone the next. That makes it hard to disentangle its impacts because researchers cannot really control it.

It is not possible to anticipate where smoke will appear or when. Scientists also prefer not to subject animals to smoke intentionally. When it comes to studying wildfire smoke and birds, the researchers try to gather data everywhere.