Tweet Tweet: Biology professor Gilbert co-authors research documenting impact of light pollution on avian activity

Tweet Tweet: Biology professor Gilbert co-authors research documenting impact of light pollution on avian activity

Wednesday, September 3, 2025

Media Contact: Elizabeth Gosney | CAS Marketing and Communications Manager | 405-744-7497 | [email protected]

Around the globe, early birds are trying out the night owl lifestyle due to artificial lights.

In a new study published in Science on Aug. 21, "Light pollution prolongs avian activity," Oklahoma State University's Dr. Neil Gilbert and Southern Illinois University's Dr. Brent Pease found that birds in the brightest nighttime environments start singing 18 minutes earlier in the morning and continue 32 minutes later into the evening compared to birds in naturally dark areas.

"On average, under the brightest night skies, a bird's day is extended by nearly an hour," said Pease, adding that that number goes up to nearly two hours for some species. "While we expected some behavioral adjustment to the lights at night, we didn't anticipate that it would be this impactful."

From March 2023 to March 2024, Gilbert and Pease analyzed approximately 4.4 million vocalizations from 583 diurnal bird species - or birds active during daytime hours - across 94 families, making their work one of the most comprehensive studies of light pollution's effects on wildlife behavior to date.

In conjunction with those vocalizations, which were gathered by the citizen-science initiative BirdWeather, Gilbert and Pease used Visible Infared Imaging Radiometer Suite satellite data to measure light pollution at each BirdWeather station.

"Human-generated lights have, in a 'blink of the eye' on evolutionary timescales, altered the natural cycles of light and dark that organisms use as 'timetables for life,'" said Gilbert, explaining that it's still unclear if prolonged activity will have positive, negative or neutral effects on birds' survival and reproduction.

"Fifty minutes of additional activity a day may represent a notable loss in resting time ... [which] may result in additional caloric needs," he said. "On the other hand, 50 additional minutes of activity may translate to increased foraging time, and potentially increased reproductive output.

"Measuring the effects of light pollution on biological fitness will require field experiments that track the survival and nest success of individual birds."

In their research, Gilbert and Pease found that some species showed particularly strong responses to artificial lighting, including American Robins, Eurasian Blackbirds, Killdeer, Northern Mockingbirds and Northern Cardinals, the latter prolonging daily activity by nearly two hours. Other species, including Eastern Bluebirds, Tufted Titmice, Carolina Chickadees and White-breasted Nuthatches, showed weaker responses to light pollution.

While the effects Gilbert and Pease found were generally consistent across regions, they noted that they had limited sampling from high-latitude areas like Alaska, as well as tropical regions.

"This hinders our ability to study latitudinal variation in response to light pollution, which we expect to be significant given the extreme variation in day length seasonality along the latitudinal gradient," Pease said.

When it comes to the region around OSU, Gilbert explained that there were fewer data points than in other parts of the country, but the analysis did include data from five stations in Oklahoma. Of the species found in the area, the Carolina Wren showed one of the strongest responses, with onset of morning vocalization occurring an average of 30 minutes earlier in the brightest landscapes compared to the darkest.

"Of some of the other iconic Oklahoma species that the OSU community may be familiar with," Gilbert said, "the Painted Bunting didn't show a strong effect, the Mississippi Kite showed a weak prolonging effect of light pollution, and the Scissor-tailed Flycatcher didn't have enough detections to be included in the analysis."

Regardless of the area of study, Gilbert and Pease recommend that policymakers and city leaders adopt the National Audubon Society's Lights Out Program and encourage residents to reduce light pollution on their properties through motion-sensing equipment and "night friendly" yard practices.

"Mitigating light pollution would not only mitigate potential harm to wildlife; it would also save money for cities and other entities that pay for lights," Gilbert said. "We believe this is a critical step forward for birds during breeding and migratory seasons."

For Gilbert, this research is the culmination of a lifelong interest in birds and a dedication to their preservation.

"I first picked up binoculars and a bird book when I was five," Gilbert said. "Now as an ecologist, my career mission is to perform research that documents human impacts on biodiversity, with the hope that my work will inform conservation efforts."

It isn't lost on Gilbert how being published in such a major journal could have long-term benefits for him, OSU students and the university.

"Having our research published in Science feels career defining," said Gilbert, who started the project within weeks of becoming a faculty member in OSU's Department of Biology. "Being a new professor and starting my own lab provided me with the freedom to branch out and explore new research avenues - I hadn't published specifically on light pollution before.

"As a follow-up, I am developing an NSF grant proposal ... that would support a postdoc, Ph.D. student and several undergraduate researchers at OSU. Publishing the paper demonstrates our ability to leverage the data for ecological analyses and hopefully increases the chances the grant will be funded."

In the meantime, OSU students have access to BirdWeather data that Gilbert used for his own work, allowing budding ecologists to conduct their own research.

"I am often approached by OSU undergraduates looking for research experience," Gilbert said. "In my opinion, one of the most valuable experiences these researchers can gain are data management and analysis skills."

As Gilbert looks forward to future research, he is enjoying the present recognition with humility.

"It honestly still doesn't feel real - Science is one of the biggest academic journals and is extremely selective in what it publishes. Publishing a paper there seemed like an impossible goal." Gilbert said. "We've been blown away by the attention the research has gotten; we've been interviewed for radio shows and newspapers literally around the world."