The DLC has released a recording of their March webinar about the Impacts of Nighttime Lighting on Ecosystems and Wildlife. They’ve also printed a summary of the webinar information on their website.
Artificial light at night (ALAN) can harm natural ecosystems – from heightening risks for migrating birds to confusing mating fireflies and disrupting nesting sea turtles. ALAN is increasing by about 2 percent each year, with outdoor nighttime lighting getting brighter and more widespread and impacting freshwater, marine, and land-based ecosystems. The impact to birds is of particular concern, since the migratory bird population in the U.S. has shrunk 28% – by approximately 2.5 billion birds – since 1970.
About 70 percent of North America’s birds are migratory, and about 80 percent of those migrate at night, using the moon and stars for navigation. Bird collisions with illuminated buildings account for the deaths of up to one billion birds annually in the U.S. Recent examples include the deaths of hundreds of birds in a single night in New York City, 1,000 to 1,500 birds dead in one night in Philadelphia, and about 400 migrating birds killed colliding with a single building in Galveston, Texas.
Current trends for addressing the impact of nighttime lighting on wildlife include developing and installing LED light sources that limit the short wavelength (violet-blue, or 400-500 nm) light often linked to light pollution. A major challenge is that standards for what constitutes blue light vary considerably from organization to organization. In addition, the optimal spectrum, duration, amount, and timing of light vary depending on wildlife taxa, and there are no standards for non-white (i.e., amber) light (the topic of a 2022 DLC whitepaper). Additional research and consistent standards are essential to the development and optimization of products that will best shield wildlife species from the impacts of light pollution.
The full webinar recording and written summary are available here.