Pup on Patrol

“Dozens of strikes occur every day,” explains Travis DeVault, a wildlife biologist at the U.S. Department of Agriculture’s National Wildlife Research Center in Sandusky, Ohio. “But your chances of being on a flight where there’s actually a problem is very low.” 

DeVault studies why animals are attracted to airports and how to deter them. Scientists believe rising strike numbers are largely due to growing bird populations. Laws like the Endangered Species Act protect certain birds and their habitats, which has helped boost their numbers. “It’s great news for birds, and we should celebrate it,” says DeVault. But more animals means a greater risk of collisions. 

“Dozens of strikes occur every day,” explains wildlife biologist Travis DeVault. “But your chances of being on a flight where there’s actually a problem is very low.” DeVault works at the U.S. Department of Agriculture’s National Wildlife Research Center in Sandusky, Ohio. He studies why animals are attracted to airports. He also looks for methods to keep them away. Scientists believe rising strike numbers are mostly due to growing bird populations. Laws like the Endangered Species Act protect certain birds and their habitats. This has helped boost their numbers. “It’s great news for birds, and we should celebrate it,” says DeVault. But more animals means a greater chance of collisions. 

Using animals like Piper to protect an airport is rare. More common measures include using loud sirens and pyrotechnics (fireworks) to scare off wildlife. These methods work only temporarily, whereas Piper has a more lasting effect. “Birds remember Piper and fly off before he jumps out of the truck,” says Edwards. “It stinks for Piper—he wants to chase something!”

Birds flock to airports because they’re appealing places for species like Canada geese—the type of bird that forced the US Airways flight to land on the Hudson River. “Airports are huge, clear areas, usually near water, that many birds feel comfortable in,” says DeVault.  

Using animals like Piper to protect an airport is rare. More common measures include using loud sirens and pyrotechnics (fireworks) to scare off wildlife. But these methods work only for a short while. Piper has a more lasting effect. “Birds remember Piper and fly off before he jumps out of the truck,” says Edwards. “It stinks for Piper—he wants to chase something!”

Why do birds flock to airports? These places attract species like Canada geese. That’s the type of bird that forced the US Airways flight to land on the Hudson River. “Airports are huge, clear areas, usually near water, that many birds feel comfortable in,” says DeVault.  

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. 

Geese also feed on turf grass. This type of short grass is planted at many airports. Scientists studied what happened when airports replaced this grass with a taller species, called switch grass. The result: 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 looked at the remains of 65 swallows that collided with planes. They found berry-like fruit from bayberry bushes in the birds’ digestive systems. After the airport removed the plants, strikes with swallows dropped by 75 percent.

Ninety-seven percent of all strikes involve birds. But DeVault says that collisions with large mammals are much more likely to damage a plane. The white-tailed deer population in the U.S. exploded from 15 million in 1984 to more than 28 million in 2010. The deer often cross into airports because the grounds are surrounded by wilderness. The easiest fix is to fence in runways. That keeps deer and other large mammals out. But fences don’t stop all land animals. Piper often scares off rodents and other small mammals that sneak through fences. Then birds that eat small mammals have less reason to fly over the airport looking for food.

With wildlife-management solutions like Piper in place, DeVault and other wildlife biologists are now turning their attention to collisions that occur outside airports. “Over the past decade, the number of damaging strikes has decreased at airports,” says DeVault. But outside airport grounds, that number has actually gone up. 

Along with rising bird populations, quieter airplane engines might be to blame, says DeVault. “By the time a bird realizes they’re on a collision course, it’s often too late for it to move out of the way.”

Solutions like Piper are helping at airports. Now wildlife biologists are turning their attention to collisions that happen outside airports. “Over the past decade, the number of damaging strikes has decreased at airports,” says DeVault. But outside airport grounds, that number has gone up. 

Rising bird populations could be one reason. Quieter airplane engines might also be to blame, says DeVault. “By the time a bird realizes they’re on a collision course, it’s often too late for it to move out of the way.”

DeVault and his colleagues are looking for solutions. They’ve found that blue lights mounted on planes cause birds to become more alert to their surroundings and avoid dangerous collisions. Engineers are also working on creating avian radar—a system that uses reflected radio waves to detect the presence of birds—to warn pilots of approaching flocks. Machines that produce focused sound waves to scare birds out of the way of planes are being studied too. 

“It will take a combination of solutions,” says DeVault. “No single method will solve every situation.” 

DeVault and other scientists are looking for solutions. One method is placing blue lights on planes. They’ve found that the lights alert birds to what’s going on around them. As a result, they avoid a strike. Engineers are also working to create avian radar. This system uses radio waves to detect nearby birds. It would give pilots a warning that a flock is approaching. Machines that produce focused sound waves are being studied too. The sound waves would scare birds out of the way of planes.

“It will take a combination of solutions,” says DeVault. “No single method will solve every situation.”