New research out of Cornell shows that the record-breaking Canadian wildfires of June 2023, which forced people across the Northeast to seek refuge from the smoke that drifted in, also quieted some of New York’s grassland birds during their breeding season.
Trifosa Simamora, a Cornell Ph.D. candidate who was one of two primary authors of a paper presenting the findings, said the birds' songs serve several necessary purposes.
"They have to sing for defending their nest, for attracting female to do the mating season, and also to, you know, like, train their offspring basically," Simamora said.
Simamora said the research doesn't address the reasons why the birds went quiet when the smoke settled in, but it establishes that they did, and that wildfire smoke can act as a stressor to the already imperiled birds.
"If, as our results suggest, smoke affects vocal behaviors critical for reproduction, imperiled grassland bird species could experience exacerbated population declines via decreased fitness," the researchers wrote in their paper.
The paper noted that with the risk and severity of wildfires rising due to climate change, New York will likely face similar smoke events in the future.
Olivia Sanderfoot is a research scientist at Cornell's Lab of Ornithology and for years she's studied how wildfire smoke affects birds and other wildlife, largely in the west. She said the findings presented in the paper are a major step forward in researchers' understanding of how wildfire smoke is affecting birds.
"It's actually a really exciting contribution that fills in some major gaps and helps to justify and support previous work that's been done in this space," said Sanderfoot, whose prior research was cited in the paper.
A side project
The findings were an outgrowth of a larger project the paper's authors are part of. They're among the researchers from Cornell's College of Agriculture and Life Sciences who are working with the state Department of Environmental Conservation to study the state of grassland birds in New York and how to best manage conservation efforts around them.
"We are trying to tease all these different environmental factors or variable and try to find what's the best way to manage them," Simamora said.
As part of that work, the researchers installed dozens of recorders at 45 sites across the state, including areas of the Iroquois National Wildlife Refuge in western New York, the Finger Lakes National Forest, and Saratoga National Historic Park.
The recorders were already installed when, in June 2023, the smoke started drifting in.
"Because we are outside so many times, almost every single day, doing our field work, we are noticing that they are not singing as much as normal," Simamora said.
They homed in on the vocalizations of eight species of birds that appear in grassland and grassland-type areas in the eastern United States. Three were "generalist" species such as red-winged blackbirds, which appear across several different habitat types. The other five were birds that rely heavily, if not exclusively, on grasslands, including bobolink, savannah sparrow, and eastern meadowlark.
The recordings ultimately bore out what the researchers heard, but the grassland species had a sharper decline in their vocalizations. The bobolinks had the most pronounced reduction in vocal activity.
One of many threats
Simamora said an important goal of her work is to improve practices around conservation and land management.
"That is why the research (is) needed for understanding what will happen and how can we help them in the future," Simamora said.
There is a growing body of evidence that what scientists call "smoke events" have physiological effects on a broad range of species. For example, in 2024 Sanderfoot published a paper on how a heavy smoke event during the 2020 wildfire season in the west "impacted acoustic activity" in the forests of eastern Washington.
But smoke is just one of many threats facing grassland birds. The bobolink, for example, has faced habitat loss and the effects of climate change that has cut the population by more than half in the last 50 years.
Light pollution, and even collisions with windows in buildings, also take a toll on the birds.
"Birds are really facing death by a thousand cuts," she said.
Sanderfoot also leads the Lab of Ornithology’s FeederWatch, a participatory science effort where people record birds at their feeders. She said that beyond things like land management and climate action, there are other actions people can take to help support birds, like keeping cats indoors and planting native gardens.
"These are all things that will help birds now and make bird populations more resilient, so that when they are faced with something like wildfire smoke, they are better poised to thrive through that," Sanderfoot said.
