VOA标准英语2010年-Decoding Bird Calls to Avoid Plane Str

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

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 Ornithology¹ are now working on a way to help prevent collisions, by deciphering the calls birds use to communicate on their migration² 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.

Ken³ Rosenberg has been an avid⁴ 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 forth⁵, 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 migratory⁶ 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 recording⁷ 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.

Pat Leonard, also with the lab, says they turned to military bases and amateur birders to help record the sounds. "We couldn't do that any other way if we didn't have everyday birders out there collecting that information for us. There are just too many birds and too many places."

 
Diane Tessaglia-Hymes
Cornell's Lab of Ornithology is busy unraveling avian mysteries.
And maybe too much data. Each location recorded eight hours worth of tape nightly, all of which had to be listened to in real time. And many of these short calls sound very similar to the untrained ear.

One recording contains the calls of 48 different types of thrushes. The Ornithology Lab teamed up with Cornell University's Bioacoustic Research Program to develop software that would decode⁸ the birdcalls.

Decoding⁹ the calls

The program can isolate¹⁰ the unique characteristics of each thrush species into algorithms much like voice recognition software. After processing, individual calls become more pronounced.

"It still may always take a human to review the results, but it should eliminate all the steps of having to sit and listen and watch the thing go by on the screen," says Rosenberg.

That means more researchers can work on night flight call projects more quickly. That data should reveal what species are flying where and when.

Developing a knowledge base of various migration flight paths and characteristics will help scientists advise airbases and airports of the best routes and times to fly to avoid large flocks of birds.

The information can also impact plans for wind turbine farms and communication towers, so they're not placed where migrating birds will fly into them. And, Rosenberg says, it will help environmentalists better gauge¹¹ another pressing issue:

"Birds are very sensitive indicators¹² of the health of the overall environment. In terms of their migration, knowing whether the timing¹³ of their migration is shifting from year to year is one of the best clues that global warming is actually happening."

A prototype of the software will be ready in approximately a year to 18 months.
 

1 ornithology   

n.鸟类学

参考例句：

• He found his vocation in ornithology.他发现自己适于专攻鸟类学。
• His main interests are botany and ornithology.他主要对植物学和鸟类学感兴趣。

2 migration   

n.迁移，移居，（鸟类等的）迁徙

参考例句：

• Swallows begin their migration south in autumn.燕子在秋季开始向南方迁移。
• He described the vernal migration of birds in detail.他详细地描述了鸟的春季移居。

3 ken   

n.视野，知识领域

参考例句：

• Such things are beyond my ken.我可不懂这些事。
• Abstract words are beyond the ken of children.抽象的言辞超出小孩所理解的范围.

4 avid   

adj.热心的；贪婪的；渴望的；劲头十足的

参考例句：

• He is rich,but he is still avid of more money.他很富有,但他还想贪图更多的钱。
• She was avid for praise from her coach.那女孩渴望得到教练的称赞。

5 forth   

adv.向前；向外，往外

参考例句：

• The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
• He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。

6 migratory   

n.候鸟，迁移

参考例句：

• Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
• This does not negate the idea of migratory aptitude.这并没有否定迁移能力这一概念。

7 recording   

n.录音，记录

参考例句：

• How long will the recording of the song take?录下这首歌得花多少时间？
• I want to play you a recording of the rehearsal.我想给你放一下彩排的录像。

8 decode   

vt.译（码），解（码）

参考例句：

• All he had to do was decode it and pass it over.他需要做的就是将它破译然后转给他人。
• The secret documents were intercepted and decoded.机密文件遭截获并被破译。

9 decoding   

n.译码，解码v.译（码），解（码）( decode的现在分词 )；分析及译解电子信号

参考例句：

• We cannot add any other memory to this system without further decoding. 如果不增加译码，就不能使系统的存贮容量有任何扩展。 来自辞典例句
• Examples using the 8250 will be presented in hardware section to clarify full-decoding schemes. 在硬件一节中有应用说明全译码方案8250的例子。 来自辞典例句

10 isolate   

vt.使孤立，隔离

参考例句：

• Do not isolate yourself from others.不要把自己孤立起来。
• We should never isolate ourselves from the masses.我们永远不能脱离群众。

11 gauge   

v.精确计量；估计；n.标准度量；计量器

参考例句：

• Can you gauge what her reaction is likely to be?你能揣测她的反应可能是什么吗？
• It's difficult to gauge one's character.要判断一个人的品格是很困难的。

12 indicators   

（仪器上显示温度、压力、耗油量等的）指针( indicator的名词复数 )； 指示物； （车辆上的）转弯指示灯； 指示信号

参考例句：

• The economic indicators are better than expected. 经济指标比预期的好。
• It is still difficult to develop indicators for many concepts used in social science. 为社会科学领域的许多概念确立一个指标仍然很难。

13 timing   

n.时间安排，时间选择

参考例句：

• The timing of the meeting is not convenient.会议的时间安排不合适。
• The timing of our statement is very opportune.我们发表声明选择的时机很恰当。