Though he doubts tales of weather radar, which has a weak signal, dispersing birds, physicist James Genova of the U.S. Naval Research Laboratory in Washington, D.C., suggests that a more powerful radar signal specifically tuned to bother birds might someday do the job.
Research on mammals had shown that heat from the microwave radiation used by radar makes a part of the inner ear expand, causing a clicking sound. In birds, this is enough to send them scurrying, Genova said.
During tests a decade ago at the USDA facility in Ohio, birds spooked earlier when a radar-using truck passed by than when the truck drove by without radar engaged, Genova said.
While his experiments suggested that the radiation did spook birds, he failed to sell the idea to the aviation community, so he moved on.
Ronald Merritt of Florida-based bird-detecting (not deflecting) radar maker DeTect Inc. said his own efforts to validate Genova's claim more than a decade ago had failed.
Blackwell, the USDA biologist, said Genova's results—combined with continued anecdotal evidence—make the idea "strong enough to pursue," though no one is known to be doing so.
Flashing Lights Targeted at Birds
Flashing, plane-mounted lights stand a better chance of getting off the ground.
Scott Philiben, an engineer and vice president at Oregon-based Precise Flight, develops flight-safety technologies, including pulsing lights that appear to reduce airplane bird strikes like one that caused the Hudson River plane crash.
The strobe-like lights were originally developed about a decade ago to make airplanes more visible to each other.
But in 2000 a Canadian floatplane operator called Philiben to tell him the crew's bird-strike rate had wildly improved after installing the flashing lights.
Curious, Philiben contacted the USDA group in Sandusky to conduct drive-by experiments on the ground.
"We have some really good results with brown-headed cowbirds," Philiben said.
But other birds, such as geese—thought to be cause of the Hudson River plane crash—didn't respond. Individual bird species may respond only to distinct wavelengths of light, experts say,
To catch the eyes of more bird species, Philiben's team is engineering systems that sweep through more wavelengths.
A recent field test by the Australian airline Qantas showed a 30 percent reduction in bird strikes after airplanes had been outfitted with the lights, Philiben noted.
Coating or embedding special materials in a plane's nose and the leading edge of the wings my have a similar shooing effect, USDA's Blackwell said.
The system would produce light in a series of wavelengths invisible to most humans but apparently annoying to birds.
"We are talking about animals that can see things that you and I can't really imagine," Blackwell said.
Blackwell is working with Precise Flight's Philiben to understand what birds see and how they react.
Time for Research?
Richard Dolbeer is a bird-strike expert in Huron, Ohio, who recently retired from the USDA, where he chaired the agency's committee on bird-strikes.
He said researchers have "piddled around" with these ideas for more than a decade.
DeTect's Merritt said even if planes were made more visible to birds, there's no guarantee the animals would respond in a manner that prevents a strike.
"Birds have evolved in an atmosphere and an environment where things happen pretty slowly," Merritt said.
"The occasional jet moving at 500 miles [805 kilometers] is quite an anomaly they don't have a way to adjust to it."
New methods to help birds get out of the way may be more necessary than ever.
As bird populations continue to rebound from historic lows in the 1960s and 1970s and air travel continues to rise, the rate of midair bird strikes could significantly increase, Dolbeer said.
"We are going to have more birds in the sky, and we're going to have more airplanes in the sky," he said, "so we really need to get busy to figure out how to keep them apart."
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