New Developments in the Use of Lights to Scare Birds From Aircraft
Every year, the U.S. civil aviation industry reports over $600 million in direct and indirect costs due to aircraft collisions with wildlife. Approximately 97.5% of these collisions involve birds. Vision is a primary sensory pathway in birds, and recent research indicates that aircraft lighting can play a potential role to increase a bird's ability to detect approaching aircraft and, subsequently, reduce bird-aircraft collisions.
In an effort to learn more about how birds detect and respond to approaching objects, NWRC scientists partnered with representatives from Precise-Flight, Inc. and California State University. The researchers filmed and timed the responses of two representative species -- the brown-headed cowbird and mourning dove -- relative to vehicle approach and different vehicle-lighting treatments. In experiments conducted at the NWRC Ohio Field Station, researchers found that mourning doves were alert to the vehicle approach on average three seconds prior to brown-headed cowbirds. However, brown-headed cowbirds exhibited avoidance behavior sooner (on average one second) before mourning doves. The findings are consistent with each species’ anti-predation behavior; mourning doves generally feed on the ground and rely on vegetation cover and their own color as a camouflage; they wait until a predator is near before bursting into flight. In contrast, brown-headed cowbirds react by improving their view of an approaching threat via high perches or flocking. Other results from the experiments have direct implications for the design of aircraft lighting systems. Researchers found that ambient light affected how quickly the birds responded to the approaching vehicles under different lighting treatments. This new information presents an opportunity for Wildlife Services and its partners to work with industry to design aircraft lighting systems that detect ambient light conditions, then tailor the lighting output to one more readily discerned by birds under those conditions (e.g., via light color, pulse rate, or a combination of effects). More research is forthcoming, but the scientists have already seen their initial findings employed by a commercial airline in a field trial and they have presented their most recent findings before representatives of a major aircraft manufacturer.