The Federal Aviation Administration (FAA) expects thousands of birds may be saved each year because of changes the agency has made to its communication tower lighting standards.
The FAA has developed a number of tower lighting configurations for tall structures to warn pilots they are approaching an obstruction, particularly during nighttime hours and in bad
weather. The configurations include white and red steady-burning lights, flashing lights and strobe lights, as well as various combinations of the three types of lights. Over the past few years, wildlife biology research (PDF) has determined that migratory birds appear to be particularly attracted to non-flashing red tower lights. The research concluded the birds are drawn toward that type of light and become confused and exhausted or collide with the towers and their supporting guy wires, killing thousands of birds every year.
As a result of the research conclusions, wildlife organizations, the telecommunication industry, and the Federal Communication Commission collectively asked the FAA to consider changing its lighting standards to reduce migratory bird fatalities by developing configurations that feature flashing lights instead of steady-burning lights, or completely omit the steady-burning lights in some cases.
After evaluating the proposal, the FAA conducted flight tests in northern Michigan to compare the traditional steady-burning lighting with a variety of different types of flashing lights. The results (PDF) showed that the new configurations that featured flashing lights provided acceptable warnings for pilots and were likely to result in a significant decrease in bird fatalities.
Based on that determination, the FAA updated its Advisory Circular (AC) (PDF) for obstruction marking and lighting in December 2015. New tower lighting schemes should now follow the revised guidance, and operators of towers with the old lighting system should submit plans explaining how and when they will transition to the new standards.