Adopting Responsible Lighting for Healthier Plants and Ecosystems
Presented by: Don Ficken, a Missouri Master Naturalist and Founder of DarkSky Missouri and Lights Out Heartland
Don’s presentation provided information on how to balance artificial outdoor lighting which affects wildlife and plants with safety concerns.
The mission of DarkSky Missouri is to raise awareness about light pollution issues in Missouri, promote quality outdoor lighting, protect our natural environment and our beautiful night sky, and educate the public how reducing light pollution can lower energy costs.
While its impact is being studied and can vary widely across species, scientists know that artificial light at night (“ALAN”) is affecting how plants grow and reproduce. It disrupts their seasonal rhythms, their ability to sense and react to natural light, and their fragile relationship with pollinators. Studies suggest clear impacts on wildlife populations due to artificial light, even from indirect exposures.
In one example of ALAN’s impact on wildlife populations, migrating birds navigate by sensing the Earth’s magnetic field. But many species also rely on light cues in the environment to ‘calibrate’ their magnetic sensitivity. Artificial light at night can disrupt these light cues. Cornell Lab of Ornithology estimates that 600 million birds die from building collisions in the U.S. each year. In a 2019 study of 125 largest urban areas in the continental U.S, the St. Louis metro area was ranked as the 5th deadliest city for birds in spring migration and 6th deadliest city for birds in fall migration.
Don provided a visual demonstrating the growth of artificial light across the U.S. (right).
DarkSky Missouri spearheads a multi-state collaboration to encourage businesses and the public to turn off lights during spring and fall bird migration. Learn more at https://www.lightsoutheartland.org.
Homeowners can do their part to reduce light pollution and foster a more native habitat by adopting the “Five Lighting Principles for Responsible Outdoor Lighting” as jointly published by DarkSky and the Illuminating Engineering Society:
FIVE LIGHTING PRINCIPLES FOR RESPONSIBLE OUTDOOR LIGHTING:
- Useful – Use light only if it is needed: All light should have a clear purpose. Consider how the use of light will impact the area, including wildlife and their habitats.
- Targeted – Direct light so it falls only where it is needed: Use shielding and careful aiming to target the direction of the light beam so that it points downward and does not spill beyond where it is needed
- Low Level – Light should be no brighter than necessary: Use the lowest light level required. Be mindful of surface conditions, as some surfaces may reflect more light into the night than intended.
- Controlled – Use light only when it is needed: Use controls such as timers or motion detectors to ensure that light is available when it is needed, dimmed when possible, and turned off when not needed.
- Warm-colored – Use warmer colored lights where possible: Limit the amount of shorter wavelength (blue-violet) light to the least amount needed.
DarkSky offers a Home Lighting Assessment program to help homeowners identify problem lighting and solutions that can reduce light pollution. Most people will find that a few simple changes can lead to lighting that is both beautiful and functional, without contributing to excessive light pollution.
This document (below) provides guidance for selecting how you can make the best solutions for your environment.
To learn more about local efforts to reduce light pollution and keep birds safe, visit DarkSkyMissouri.org and LightsOutHeartland.org.
Thank you to Donna Short for assembling these highlights!
