Shooing Birds Away With Sound
(Inside Science) -- Humans and birds don't always get along. We clash over resources like food and shelter, and sometimes we clash literally -- when birds collide with airplanes.
But what if we could solve such problems by taking advantage of how birds respond to sound?
"Birds are in an increasing conflict with humans over things that we both want. They want to get food. We want to grow food, and so what we're trying to do is trying to resolve some of that conflict using technology that's based on understanding how the birds behave," said John Swaddle, professor of biology at the College of William and Mary.
One of Swaddle's technologies is designed to drive birds away from places where they're not wanted, like airports. The device is called a sonic net.
"What we're doing is we're broadcasting sounds that make it difficult for the birds to hear each other. Now, if birds can't hear each other, they can't listen out for predators. And if birds can't listen for predators, they want to go somewhere else," said Swaddle.
You might think the roar of airplane engines would be enough to drive birds away. But plane engines have a lower pitch than birdsong, so birds can still "talk" over them.
The sounds of the "sonic net" are more similar to those of a bird's voice. According to Swaddle, the device works so well that a company now uses it to provide bird-repelling services around the world.
"They have several contracts in Europe, in Asia, where they have actually installed these speaker systems at airports, at farms, and have been successful at removing birds in the long term," said Swaddle.
Swaddle is also working on a different technology designed to warn birds before they hit things.
"Surprisingly, you might find that when birds are flying, they're not really looking where they're going," said Swaddle.
To solve this problem, the device would project a beam of sound about 100 meters -- or about 328 feet -- in front of obstacles like wind turbines and buildings. Swaddle calls it an acoustic lighthouse.
"So when a bird approaches it, at that 100-meter mark, it suddenly pays attention to what's in front of it, giving it a chance to fly around or go back. It's like honking your horn. Certainly, they will look up and pay attention to what's in front of them," said Swaddle.
Both the sonic net and the acoustic lighthouse are based on our understanding of bird behavior.
"There's a need in society to keep understanding and discovering more about what birds do, and then we'll have better solutions for these problems," concluded Swaddle.
