Efficacy of aircraft landing lights in stimulating avoidance behavior in birds

Aircraft collisions with wildlife (primarily birds) are costly in terms of injury or loss of human life, loss of the animals involved, damage to property and business, and the use of lethal control of wildlife at airports worldwide. One potential nonlethal technique to reduce bird––aircraft collisions——pulsed white and wavelength-specific aircraft-mounted light——has been considered for nearly 3 decades, but the efficacy of the technique has not been evaluated quantitatively. We tested the hypothesis that during daylight, captive birds exposed to an approaching ground-based vehicle exhibiting pulsing 250-W white aircraft landing lights would initiate avoidance behavior more quickly than birds experiencing an oncoming vehicle with nonpulsing (steady) or no lights (control). In experiments involving captive brown-headed cowbirds (Molothrus ater), Canada geese (Branta canadensis), European starlings (Sturnis vulgaris), herring gulls (Larus argentatus), and mourning doves (Zenaida macroura), only cow-birds exhibited a response to the landing lights, but not consistently. Specifically, cowbird groups (9 groups/treatment, 6 birds/group) responded more quickly to pulse versus control treatments, equating to a greater distance (x̄ ±± SE) of the approaching vehicle from mid-cage per reacting bird (control: 35.8 ±± 9.7 m, pulse: 50.5 ±± 10.9 m; P == 0.015). However, in a subsequent experiment involving the exposure of cowbirds to control, pulse, and steady-light treatments, we observed no difference in response among treatment groups. Although 250-W white landing lights pulsed at 45 cycles/min influenced behavior of captive birds in response to an oncoming ground-based vehicle, the avoidance response was inconsistent across experiments with cowbirds, and we observed little or no avoidance behavior in experiments with other species. We suggest that further research is needed to investigate avian response to specific light wavelengths and pulse frequencies.