新托福阅读材料：Decoding Bird Calls to Avoid Plane Strikes

鸟类语言

Birds and planes have been colliding since the Wright brothers first took to the air.

自莱特兄弟发明飞机以来，就一直发生鸟与飞机相撞事故。

There are dozens of bird strikes each day, causing hundreds of millions of dollars in damage to airplanes each year, and putting the lives of passengers and crew members at risk. Researchers at Cornell Lab of Ornithology are now working on a way to help prevent collisions, by deciphering the calls birds use to communicate on their migration routes.

Rosetta Stone for birds

There's more to the language of birds than songs. They also use short calls - less than a second long. And each species speaks its own language.

Ken Rosenberg has been an avid bird-watcher since he was a boy. Today he works at the Cornell Lab of Ornithology, unraveling avian mysteries. He says that birds use these short calls most often during migration.

"What we suspect is that these are calls that the birds are actually using to communicate back and forth, to locate each other," he says. "'Don't crash into me!' Of course, we're guessing, but given the way they call, it's really just a social thing."

Craig Kerns

Birds use short calls - less than a second long. And each species speaks its own language.

Until recently scientists weren't aware of the extent of these calls, because most bird migration takes place at night.

"It really began with amateur bird watchers who were noticing these sounds in the sky and knew that they were birds migrating overhead," says Rosenberg. "A few people became detectives and tried to figure out what these sounds were."

Bird call detectives

The migratory flyways over the United States are crowded with billions of birds every spring and fall.

By aiming special microphones at the night sky during these times and recording the passing calls, scientists realized they could determine what kinds of birds were flying overhead, and learn their migration schedules and flight paths. But there was a lot of sky to cover.