Summer is considered a high use period for overflights, where the park can experience hundreds of air tours in one day. Grand Canyon scientists are particularly concerned about the effect of overflights on wilderness quality. Overflights affect not only visitors who seek natural quiet, but can also affect wildlife as well. A growing amount of research indicates anthropogenic noise can interfere with wildlife species reliant on sound, especially for mating purposes and finding prey.
A 2016 study found that Northern Saw-Whet owls had much lower success in finding food when disturbed by human-caused noise (Mason et al. 2016).
Another study found that helicopter overflights negatively impacted the foraging efficiency of desert bighorn sheep at the Grand Canyon (Stockwell et al. 1987). Bighorn sheep, Mexican Spotted Owls, California condors, and mountain lions are all species within the Grand Canyon scientists believe are affected by noise pollution.
Therefore, protecting the natural soundscape is important for reducing these impacts and providing the more than 6 million annual visitors to the park with access to the intrinsically valuable resource of natural sounds and quiet.
