Bird-Friendly Communities

Lights Out and Reflective Surfaces

Pioneering innovative approaches to make buildings safer for birds


The Issue
Twice each year, billions of birds fly between wintering and breeding grounds, facing innumerable threats along the way. The majority of birds migrate at night, using the night sky to help them navigate. During the day, they rest and refuel, relying on green space, water and other necessary resources. Artificial lights and skyglow around buildings can be fatal to migrating birds. Some are casualties of nighttime collisions with windows and walls. Others circle in confusion until dawn, when they land and are subject to other urban threats. This issue impacts hundreds of species, including priority species like the Wood Thrush, Golden-winged Warbler, and Seaside Sparrow. Lights Out is a national effort to reduce this problem by working with building owners, managers, and residents to turn off unnecessary lights during periods when they are most likely to affect migrating or nocturnal birds. 

The Impact
On-going research in Chicago, where over 30,000 birds collided with a single building over a  20-year period, is documenting the magnitude of the problem as well as an important part of the solution – turning out unnecessary lights reduced bird mortality at that problematic building by over 80%. Dousing lights has the added benefit of reducing energy use and saving money.

Minimize unnecessary bird deaths

Save money by reducing energy usage

Support your organization’s sustainability goals

Receive recognition for sustainable, bird-friendly practices

Be recognized as a regional and national leader in sustainability and bird conservation
Turn off exterior decorative lighting
Extinguish spot and flood-lights
Substitute strobe lighting where possible
Reduce lobby and atrium lighting wherever possible
Turn off interior lighting especially on upper floors
Substitute task and area lighting for workers staying late or pull window coverings
Down-shield exterior lighting to eliminate all light directed upward and horizontal glare
Install motion sensors and automatic controls wherever possible
When converting to new lighting carefully assess quality and quantity of light needed, avoiding over-lighting with newer, brighter technology
While all unnecessary lighting should be reduced, the exterior decorative lights and lighted upper stories are a priority as they have the ability to disorient night migrating birds, especially in inclement weather.

Light induced collisions can occur at any time of the year but they tend to peak during periods when birds are migrating through an area or, in some locations, when certain nocturnal species are present. Because migrating and nocturnal birds can be active throughout the night lighting should be reduced or turned off for as much of the nighttime as possible during peak collision periods.
The Issue
Birds face innumerable threats in our human built environment and our glass surfaces are one of the biggest. 
During daylight hours, birds collide with reflective surfaces when they stop to feed or rest, when avoiding a predator or flying from tree to tree. Shiny glass exteriors, internal plants near windows, glass corners, and greenery close to buildings can all be deadly as birds are unable to distinguish reflection from open flyway. For every collision victim found, three more typically go unseen, flying out of sight before falling or being carried away by predators.
The Impact
Window collisions are one of the leading direct human causes of bird mortality. A 2014 study by the US Fish and Wildlife Service and the Smithsonian Institution estimated that between 365 and 988 million birds are killed annually by building collisions in the U.S.


Minimize unnecessary bird deaths
Support your organizations sustainability goals
Receive recognition for sustainable, bird-friendly practices
Be recognized as a regional and national leader in sustainability and bird conservation
Solutions: People ‘see’ glass because we understand buildings. Birds need strong clues on or around glass reducing reflective surface to warn them that it’s there.
Reducing reflective surface collisions
Create patterns on reflective glass surfaces (quantity and spacing matter: multiple markings 2 to 4 inches apart are recommended)
Install external screens on windows
Close blinds or curtains
Move plants away from windows
Place bird feeders directly on windows
Bird-building collisions can happen at any time of the day and year but tend to increase during migration and when young birds start flying. Therefore, the most crucial times for these measures are during spring and fall migration and in the breeding season in  your area.

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