Geese also feed on turf grass, a species of short grass that is commonly planted at airports. Scientists have found that replacing this grass with a taller species called switch grass attracts fewer geese. DeVault says plants that bear fruit also attract wildlife. Strikes with tree swallows have been a problem at John F. Kennedy International Airport in New York City. Scientists examined the remains of 65 swallows involved in collisions and found berry-like fruit from bayberry bushes in the birds’ digestive tracts. The airport decided to remove the plants, and since then, strikes with swallows have decreased by 75 percent.
While 97 percent of all strikes involve birds, collisions with large mammals are far more likely to damage a plane, says DeVault. The white-tailed deer population in the U.S. exploded from 15 million in 1984 to more than 28 million in 2010. Deer often cross into airports because many times the grounds are surrounded by wilderness. The easiest solution is to fence in runways to prevent deer and other mammals from entering.
Fences don’t stop all land animals, though. Piper frequently frightens off rodents and other small mammals that sneak through airport fencing. Fewer prey in the area means birds have less incentive to fly over the airport looking for food.