For humans, the early days of the COVID-19 pandemic were a stressful time, marked by fear, isolation, canceled plans and uncertainty. But for birds that inhabit developed areas of the Pacific Northwest, the reduction in noise and commotion from pandemic lockdowns may have allowed them to use a wider range of habitats in cities.

A new 91̽�� led by reports that many birds were just as likely to be found in highly developed urban areas as they were in less-developed green spaces during the peak of the COVID-19 lockdowns. The paper was published Aug. 11 in the journal Scientific Reports.

“Our findings suggest that some birds may have been able to use more spaces in cities because our human footprint was a little lighter,” said Sanderfoot, who completed the study as a doctoral researcher in the 91̽��School of Environmental and Forest Sciences and is now a postdoctoral scholar in the Department of Ecology and Evolutionary Biology at the University of California, Los Angeles.

“For about half of the species we observed, neither land use nor canopy cover had an effect on their site use. That’s very interesting, because we would expect that whether a habitat was mostly covered in concrete or vegetation would tell you something about what birds would be there,” Sanderfoot said.

In the spring of 2020, Sanderfoot and colleagues recruited more than 900 community scientists in the Pacific Northwest to participate in the study. The volunteers chose their own monitoring sites — mostly backyards and parks where they could safely comply with public health orders — and recorded the birds they observed over a 10-minute period at least once a week. This community science approach allowed the researchers to gather data despite the lockdowns and gave many volunteers a welcomed distraction from the stresses of the pandemic.

“I am loving being a part of this!” said Nadine Santo Pietro, a study volunteer, in a written comment as part of the project. “I signed up to observe once a week for 10 minutes but it has become so much more than that. … I am learning so much! And it’s given me something positive to focus on during this strange time we are in right now.”

Volunteer Elaine Chuang wrote: “Being involved not only as a survey participant, but also as a mentor gives me a role in bringing greater appreciation of birds and nature in general to the community at large.”

Among the 35 species that showed the strongest changes in behavior were some of the Pacific Northwest’s most iconic, including black-capped chickadees, great blue herons, downy woodpeckers and Wilson’s warblers. The researchers focused on 46 bird species overall, which were observed by the study volunteers during more than 6,000 individual surveys.

In order to compare the volunteers’ bird observations to human activity, Sanderfoot and her colleagues used data from Google’s Community Mobility Reports, which track the relative amount that people moved around at various points during the pandemic. While most people spent spring of 2020 isolated in their homes, many began venturing out again over the course of the study period.

As people returned to public spaces and human activity increased, the study volunteers recorded an increase in sightings of several bird species. Because they were mostly monitoring in parks and backyards, which tend to be more heavily vegetated, provide more canopy cover and offer more resources for birds than other areas in cities, this could indicate that these green spaces are an important refuge for urban birds.

“The birds may have been elsewhere at the height of the lockdowns, because human activity wasn’t as much of a disturbance, but then returned to those vegetated areas as the activity increased again,” Sanderfoot said. “This could tell us how important it is to build green spaces into our cities. That’s the biggest takeaway for me.”

Other co-authors are , a professor in the 91̽��Department of Environmental and Occupational Health Sciences, and , an associate professor in the 91̽��School of Environmental and Forest Sciences.

This research was funded by the National Science Foundation Graduate Research Fellowship Program and the McIntire-Stennis Cooperative Forestry Research Program from the USDA National Institute of Food and Agriculture.

For more information, contact Sanderfoot at osanderfoot@g.ucla.edu, Kaufman at joelk@uw.edu and Gardner at bg43@uw.edu.

Press release written by Will Shenton, 91̽��College of the Environment.

As smoky air becomes more common during Washington’s wildfire season, many wildlife enthusiasts wonder: What happens to the birds?

Few studies have looked at wildfire smoke impacts on animals, let alone birds. And as Washington and the larger West Coast continue to experience more massive wildfires and smoke-filled air, understanding how birds are affected by smoke — and how air pollution may influence our ability to detect birds — are important factors for bird conservation.

Researchers from the 91̽�� now provide a first look at the probability of observing common birds as air pollution worsens during wildfire seasons. They found that smoke affected the ability to detect more than a third of the bird species studied in Washington state over a four-year period. Sometimes smoke made it harder to observe birds, while other species were actually easier to detect when smoke was present. The June 29 in the journal Ornithological Applications.

“We want to know how wildfire smoke affects birds and other wildlife, and this study is a great place to start,” said lead author , a doctoral candidate in the 91̽��School of Environmental and Forest Sciences. “Smoke clearly has an impact on detection of wildlife, and that hasn’t been adequately explored in the literature to date. Now we know that smoke pollution specifically affects our observations of birds and our ability to detect them.”

The researchers combined data from , an online citizen-science program managed by the Cornell Lab of Ornithology, with publicly available data from an extensive network of air quality monitors across Washington state. They were able to analyze how fine particulate matter, known as PM2.5 and a marker of smoke pollution, affected the probability of observing 71 common bird species during the wildfire seasons of 2015 to 2018. Higher concentrations of smoke affected the chances of observing 37%, or 26, of the bird species included in the study.

Sixteen of the bird species were harder to observe with more wildfire smoke, the study found. These include turkey vultures, Canada geese, two gull species, bald eagles and several other birds of prey. Many of these birds are observed circling high above the ground, so it’s not surprising that people would have a harder time detecting them on smoky days, the authors said. However, 10 additional species were easier to observe when smoke concentrations were higher. These include three types of warblers, cedar waxwing, spotted towhee and California quail.

The reasons for this aren’t clear and are outside of the scope of this study, but the authors lay out some hypotheses for future exploration. It could be that reduced visibility due to smoke pushes some birds lower to the ground where they can be more easily seen and heard. Or, as smoke prompts birds of prey to relocate, that could alleviate pressure on some songbirds and cause them to be more active — and thus more detectable by people.

“These behavioral changes are all hypotheticals, and we very much hope that researchers follow up on them because we have a lot to learn about how smoke affects wildlife,” Sanderfoot said.

Conservation and management efforts rely on the ability to observe animals in the wild, and it’s no different for birds. Air pollution clearly plays a role in detecting animals, and this paper makes the case that it should be considered alongside other factors like time of day, temperature and precipitation that all can influence observations of animals.

“If we see or hear birds more or less frequently because of smoke, that also impacts bigger inferences we make in terms of how certain bird populations are doing,” said senior author , an associate professor in the School of Environmental and Forest Sciences. “We want to get that part right, so we first need to understand the effect of air pollution on how we’re seeing birds in the wild.”

The researchers chose a four-year study period that included some summers where wildfire smoke was heavy in parts of the state, and other summers where smoke was negligible. All of the species included in the study had to have had at least 750 observations recorded for the first year (2015), and all observations used were within about 20 miles (32 kilometers) of an air quality monitor in Washington.

Data from the catastrophic 2020 wildfire season was not part of this analysis, although air quality during that period was worse than in any of the years in the study. As extreme wildfire seasons like 2020 become more common, it’s important to consider the influence of events like these in future studies, the researchers said.

This research was funded by the National Science Foundation and the McIntire-Stennis Cooperative Forestry Research Program from the USDA National Institute of Food and Agriculture.

For more information, contact Sanderfoot at oliviavs@uw.edu and Gardner at bg43@uw.edu.