Turning Off Half of City Lights at Night Could Cut Bird Mortality by Up To 60 Percent
The highest mortality counts happen on windy nights during large migration events—when the highest number of lights were left on.
This article is by Berly McCoy and was originally published by Anthropocene magazine.
Like an insect attracted to a bug zapper, artificial light is harming migratory birds by throwing them off course and causing deadly collisions. Now, a new study highlights just how beneficial switching off the lights can be. The work, published in the Proceedings of the National Academy of Sciences, analyzed decades of bird collision and lighting data at McCormick Place Lakeside Center in Chicago, Illinois.
Building collisions are the second leading human-driven cause of fatalities among birds in North America and have substantially contributed to hundreds of millions of deaths every year. Because decreasing artificial lighting is increasingly recognized as an important step toward lowering collisions, lights-out campaigns are gaining popularity.
To understand the factors that play the biggest role in bird fatalities and the relationship between building lights and bird deaths, the research team developed a mathematical model using 21 years of seasonal bird collision data from McCormick Place. The researchers inputted the number of birds that were found dead outside the building along with how many lights were left on overnight. Because lighting isn’t the only factor that could cause bird collision mortality, the team also included weather and migration numbers in their model.
The researchers found that, along with large migration occurrences, the number of lighted windows on a given night was the strongest predictor of bird collisions, even though weather patterns were also important. The highest mortality counts happened on windy nights during large migration events when the highest number of lights were left on.
“The sheer strength of the link between lighting and collisions was surprising,” says lead author Benjamin Van Doren, in a press release. “It speaks to the exciting potential to save birds simply by reducing light pollution.” The team estimated that turning off half of the lights at McCormick Place could decrease bird collisions by 11 times in the spring and 6 times in the fall, and that approximately 60 percent of bird mortality could be avoided if lights were extinguished to the minimum levels recorded.
The study highlights the importance of measuring when bird collisions are more likely to occur—windy nights during high migration—in order to identify the most important times to cut out the lights.
Anthropocene magazine, published by Future Earth, gathers the worlds’ best minds to explore how we might create a Human Age that we actually want to live in.
Berly McCoy is a freelance science writer and media producer based in Northwest Montana covering biology, chemistry, food and the environment. Her work has appeared in Scientific American, PBS NewsHour, NPR, Hakai and elsewhere. Find her on Twitter at @travlinscientst.
Source: Van Dorena, B. M. et al. Drivers of fatal bird collisions in an urban center. PNAS, 2021.
In The News
In The News
SACRAMENTO, Calif. -- A recent report says that more than a third of Californians are living below or near the... Read More
SACRAMENTO, Calif. -- A recent report says that more than a third of Californians are living below or near the poverty line, according to the latest available data. Without social safety net programs, the report further says, that figure would have been much higher. California, the... Read More
GREENVILLE, Calif. (AP) — California's largest wildfire has leveled much of the downtown and some surrounding homes in a small... Read More
GREENVILLE, Calif. (AP) — California's largest wildfire has leveled much of the downtown and some surrounding homes in a small Northern California mountain community. The Dixie Fire tore through the Greenville on Wednesday evening, destroying businesses and homes as the sky was cast in an orange... Read More
A recently released documentary is showing how the Navajo Nation and Hopi Tribes are pushing for equitable and renewable energy... Read More
A recently released documentary is showing how the Navajo Nation and Hopi Tribes are pushing for equitable and renewable energy sources for the many people living without electricity in the Black Mesa territory of northern Arizona. “Local Leadership, Global Change: Navajo Nation & Hopi Tribe,” produced... Read More
WASHINGTON (AP) — The number of Americans applying for unemployment benefits fell last week by 14,000 to 385,000, more evidence... Read More
WASHINGTON (AP) — The number of Americans applying for unemployment benefits fell last week by 14,000 to 385,000, more evidence that the economy and the job market are rebounding briskly from the coronavirus recession. The Labor Department reported Thursday that unemployment claims — a proxy for... Read More
WASHINGTON -- A Senate committee went public Wednesday with the kind of information about China’s use of U.S. technology that... Read More
WASHINGTON -- A Senate committee went public Wednesday with the kind of information about China’s use of U.S. technology that normally would stay behind the closed doors where clandestine issues are discussed. Select Committee on Intelligence leaders revealed that China’s unauthorized use of technology is costing... Read More
President Joe Biden is expected to announce Thursday that his administration is setting a new national goal for the sale... Read More
President Joe Biden is expected to announce Thursday that his administration is setting a new national goal for the sale of electric vehicles -- wanting half of all new vehicles sold in the U.S. by 2030 to be powered by electricity. The executive order Biden will... Read More