Canadian wildfire smoke has a reach far beyond the forests that burn. Even when the flames are hundreds of miles away, New York’s air can change rapidly—and with it, the signals that scientists rely on to track wildlife.
In a new University at Buffalo study published in Biodiversity and Conservation, researchers report that rising fine particulate matter (PM2.5), a marker strongly associated with wildfire smoke, is linked to fewer sightings of many breeding birds across New York State. The analysis drew on a period that included the 2023 season, when Canadian wildfires produced record-setting smoke transport.
The team first quantified PM2.5 during New York’s 2021–2023 breeding seasons. Concentrations peaked in 2023, when smoke degraded air quality through June and July, pushing PM2.5 above World Health Organization guidance multiple times—at peaks up to eightfold the recommended limit.
Next, they matched those air-quality measurements to nearly 99,000 birdwatching checklists from Cornell University’s eBird database, a citizen-science platform that compiles observations submitted by participants with varying experience levels. To reduce bias, the researchers applied rigorous data filtering and statistical controls.
Across the three seasons, they analyzed 84 breeding bird species. Overall, 65% of species showed altered detectability as PM2.5 rose, with nearly half becoming less likely to be observed during smokier intervals. Many affected species were migratory forest songbirds, including warblers, thrushes, and vireos.
One plausible mechanism is behavioral: smoky conditions may suppress singing, reduce movement, or shift activity deeper into dense canopy, making birds harder to detect even if they remain present. The authors emphasize that the ecological meaning of “absence” in observation data is not straightforward when air quality changes.
Interestingly, 15 species were more likely to be observed at higher PM2.5, while 29 showed no significant change. The study notes that these patterns may reflect where birdwatchers choose to look during poor air-quality days—often favoring more open habitats rather than changes in bird abundance alone.
The key takeaway is methodological as well as ecological. If smoke-driven detectability shifts are ignored, biodiversity models may misinterpret temporary observation changes as real population declines. With climate change intensifying wildfire frequency, incorporating air-quality context becomes essential for reliable monitoring.
By treating PM2.5 as an exposure variable that can reshape what field surveys “see,” this work offers a framework for improving species distribution estimates during smoke events—turning a pervasive environmental disturbance into a measurable factor in conservation science.
Subject of Research: Animals
Article Title: Wildfire smoke alters observations of 65% of breeding bird species in New York State
News Publication Date: 3-Jul-2026
Web References: https://link.springer.com/article/10.1007/s10531-026-03406-9
References: 10.1007/s10531-026-03406-9
Keywords: wildfire smoke; PM2.5; biodiversity indicators; ecological diversity; biodiversity conservation; species diversity; avian monitoring; detectability bias; climate change effects; ecological diversity indicators
