Artificial light at night (ALAN) refers to the use of electric light sources in outdoor spaces. As cities and infrastructure grow, ALAN is used for various applications, from lighting roadways and parking lots for safety to illuminating architecture. While safety is crucial, ALAN has created problems for wildlife that have lived under natural light at night (moonlight and starlight).
ALAN disrupts sleep cycles, displaces wildlife from their habitats, disrupts migration patterns and breeding rituals, and alters hormone production. To combat these effects, wildlife-friendly lighting standards advocate for specific fixtures, design principles, and lighting control methods to minimize disruption to wildlife and their natural environment.
Wildlife Lighting Standards Recommendations
There are several organizations that establish and promote wildlife-friendly lighting standards and one of the most prominent is the International DarkSky Association (IDA), an independent organization offering certification and educational resources.
The Florida Fish and Wildlife Conservation Commission (FWC) and the U.S. Fish and Wildlife Service (USFWS) are key government agencies that provide guidelines and resources for wildlife lighting. They are the most referenced for sea turtle-friendly lighting and bird-friendly lighting, and they have developed the Wildlife Lighting Certification Program to ensure lighting practices are safe for wildlife.
International DarkSky Association
The Florida Fish and Wildlife Conservation Commission (FWC) and the U.S. Fish and Wildlife Service (USFWS) are key government agencies that provide guidelines and resources for wildlife lighting. They are the most referenced for sea turtle-friendly lighting and bird-friendly lighting, and they have developed the Wildlife Lighting Certification Program to ensure lighting practices are safe for wildlife.
Aside from the five principles, IDA has a few other core functions, including the DarkSky certification program and DarkSky Approved program, as well as education and outreach. The IDA also works as a resource to aid in crafting ordinances and legislation for municipalities to help combat the growing problem of light pollution.
IDA’s Five Lighting Principles for Responsible Outdoor Lighting
A guide to assist lighting professionals when designing exterior lighting, these simple principles are intuitive and relatively easy to implement and can have an enormous impact when applied correctly to reduce light pollution and maintain dark skies and healthy habitats for wildlife.
Many guidelines, like “Low Level” and “Targeted,” are subjective. Testing and mockups in the field can help determine what is “Low Level” in the context of the project site. For example, a 4-watt luminaire may be appropriately bright in a city park but too bright in a rural residence.
DarkSky Approved Program
The DarkSky Approved program provides third-party approval for products, lighting designs and projects, ensuring that they meet necessary requirements that abide by Five Lighting Principles for Responsible Outdoor Lighting.
When searching for outdoor luminaires, the DarkSky Approved seal can help guide the fixture selection for projects that need to meet any DarkSky requirements. DarkSky approved fixtures can be found with the DarkSky Approved Seal on manufacturers cut sheets or through the DarkSky Database. Full program requirements can also be found in the DarkSky Approved Luminaires Guidelines.
Turtle-Safe Lighting
The Florida Fish and Wildlife Conservation Commission (FWC) manages fish and wildlife resources for their safety and the good of the community. One large part of the FWC’s programs is establishing turtle-safe lighting practices.
Turtle nesting seasons typically run from May through October in Florida. As hatchlings leave their eggs, they must make the trip back to the ocean across the beach where they were laid. Their natural means of navigation is following the naturally blue moonlight, which is brightest on the water horizon. Traditional ALAN can disturb this process, so turtle safe lighting ordinances have been implemented to protect this journey and save turtle lives. The most important aspect of turtle safe lighting is the use of no blue wavelength light (shorter than 560nm).
The FWC’s Wildlife Lighting Certification Program helps identify lighting fixtures which meet requirements for turtle-safe lighting. Additionally, the DarkSky Approved program also has their own specific DarkSky Sea Turtle Sensitive Approved program, which has nearly identical standards.
Bird-Friendly Lighting Standards
Bird populations worldwide are highly susceptible to the negative impacts of artificial light at night (ALAN). Eighty percent of North American birds migrate overnight, relying on magnetoreception to detect Earth’s magnetic poles. Studies show that high levels of blue spectrum light can impair this sense, disorienting birds and causing them to fly in non-migratory directions.
In urban areas, blue spectrum light traps birds in “bubbles” of artificial light, leading to collisions, exhaustion, and mass-mortality events, especially on foggy or low cloud ceiling nights when birds fly lower than normal.
The standards and strategies set by DarkSky and the FWC sea turtle program are similar to bird-friendly lighting recommendations. Turning off unnecessary lighting is the most effective solution, especially during spring (April-May) and fall (August-October) migration seasons and on cloudy or foggy nights. Additionally, if birds become trapped in bright light, turning lights off for 15 to 20 minutes can help them escape. Automatic timers can create breaks if monitoring is not feasible. To reduce light pollution from interiors, close blinds, shades, or curtains at night, or use window tinting.
Bird-Friendly Lighting Ordinances
Bird-friendly lighting ordinances are often grouped with bird-friendly building ordinances. Architects and designers can use construction materials, glazing, and lighting to create safer environments for birds.
In the U.S., these ordinances are mostly managed by local municipalities. Notably, Maui County recently enacted stringent requirements for bird and wildlife-safe lighting, including outdoor fixtures emitting no more than 2% of light from the blue spectrum (400nm-500nm), no uplight, and full fixture shielding. For more information on other ordinances, refer to The Yale Bird-Friendly Building Initiative’s national database.
DMF’s Wildlife-Friendly Lighting Solutions
DMF offers a variety of fixtures that are both DarkSky approved and turtle-sensitive for recessed downlighting and cylinder applications. Approved fixtures are limited to certain configurations.
- DarkSky Approved
- Luminaires cannot include decorative trims and must be 3000K CCT or lower.
- M Series Residential (4-inch aperture) and X Series recessed downlights both offer configurations.
- M Series and X Series Cylinders have configurations. Cylinders must be downlight (direct only), without any uplight.
- Look for the DarkSky Approved seal on DMF specification sheets for approved fixtures.
- Dark Sky Approved Turtle Sensitive
- DMF turtle-friendly lighting fixtures come in 300 lumen output, specialty CRI and Turtle & Wildlife Friendly (TF) spectrum.
- M Series Residential and X Series Recessed downlights are both available in turtle sensitive configurations.
- M Series and X Series Cylinders are also available in TF configurations, in downlight configurations only.
Note that DMF Turtle and Wildlife Friendly fixtures are not currently listed as FWC Certified but are designed within the required specifications and are certified DarkSky Approved Sea Turtle Sensitive.
To review the Wildlife Lighting Technical Bulletin, which includes references, click here.