美国国家公共电台 NPR North America Has Lost 3 Billion Birds, Scientists Say

 

AUDIE CORNISH, HOST:

Scientists worry that bird populations across North America have been decreasing. NPR's Nell Greenfieldboyce reports that researchers now have a rough estimate of how the total number of birds has changed since 1970.

NELL GREENFIELDBOYCE, BYLINE¹: Ken² Rosenberg is 65 years old, and he says, over his lifetime, he's noticed a decline in migrating birds, like evening grosbeaks.

KEN ROSENBERG: When I was a kid, there were years when you could see 50 or 100 at your feeder, and now you're lucky in a big year to see 10.

GREENFIELDBOYCE: Rosenberg works at the Cornell Lab of Ornithology³. He knew that some bird populations, like bald eagles, have actually gone up over the last few decades. So he wondered how the total number of birds in the sky might be changing.

ROSENBERG: Are there fewer birds than there were in 1970, or are we seeing a shift and losing some of the rare specialized⁴ species and shifting towards more generalist, more common birds, species that are more adapted to humans?

GREENFIELDBOYCE: To find out, he and some colleagues gathered all the data they could on over 500 bird species; a lot of it came from bird surveys done each year by volunteers. They also used data from weather radar⁶ installations that can detect flocks of migrating birds. They crunched⁷ all the numbers and were stunned⁸ by the results.

ROSENBERG: By our estimates, it's a 30% loss in the total number of breeding birds since 1970 - less than 50 years - and that's 3 billion birds.

GREENFIELDBOYCE: Three billion fewer birds. Rosenberg says most of that loss comes from bird families like sparrows, finches, warblers and swallows.

ROSENBERG: Things like meadowlarks, dark-eyed junco, horned lark⁹, red-winged blackbird.

GREENFIELDBOYCE: And the main culprit is probably the loss of their natural habitat, with increased urbanization and more agriculture. This massive bird accounting¹⁰ project is described in the journal Science - it's not exactly as precise as balancing your checkbook. Ted⁵ Simons is an ecologist with North Carolina State University. He says trying to count and track birds is a daunting¹¹ task.

TED SIMONS: We're certainly far from having the tools and having the resources to have real high confidence in our estimates of these populations.

GREENFIELDBOYCE: Still, he thinks it's very likely that the total bird population has substantially declined. And others say the new estimate sounds about right, like migratory¹² bird researcher Kristen Ruegg at Colorado State University.

KRISTEN RUEGG: Overall, the conclusions weren't necessarily surprising. I mean, they were depressing but not surprising.

GREENFIELDBOYCE: She says having this estimate is a way to wake people up to the problem.

Nell Greenfieldboyce, NPR News.

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1 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

2 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.

3 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。

4 specialized   

adj.专门的，专业化的

参考例句：

• There are many specialized agencies in the United Nations.联合国有许多专门机构。
• These tools are very specialized.这些是专用工具。

5 ted   

vt.翻晒，撒，撒开

参考例句：

• The invaders gut ted the village.侵略者把村中财物洗劫一空。
• She often teds the corn when it's sunny.天好的时候她就翻晒玉米。

6 radar   

n.雷达，无线电探测器

参考例句：

• They are following the flight of an aircraft by radar.他们正在用雷达追踪一架飞机的飞行。
• Enemy ships were detected on the radar.敌舰的影像已显现在雷达上。

7 crunched   

v.嘎吱嘎吱地咬嚼( crunch的过去式和过去分词 )；嘎吱作响；（快速大量地）处理信息；数字捣弄

参考例句：

• Our feet crunched on the frozen snow. 我们的脚嘎吱嘎吱地踩在冻雪上。 来自《简明英汉词典》
• He closed his jaws on the bones and crunched. 他咬紧骨头，使劲地嚼。 来自英汉文学 - 热爱生命

8 stunned   

adj. 震惊的，惊讶的 动词stun的过去式和过去分词

参考例句：

• The fall stunned me for a moment. 那一下摔得我昏迷了片刻。
• The leaders of the Kopper Company were then stunned speechless. 科伯公司的领导们当时被惊得目瞪口呆。

9 lark   

n.云雀，百灵鸟；n.嬉戏，玩笑；vi.嬉戏

参考例句：

• He thinks it cruel to confine a lark in a cage.他认为把云雀关在笼子里太残忍了。
• She lived in the village with her grandparents as cheerful as a lark.她同祖父母一起住在乡间非常快活。

10 accounting   

n.会计，会计学，借贷对照表

参考例句：

• A job fell vacant in the accounting department.财会部出现了一个空缺。
• There's an accounting error in this entry.这笔账目里有差错。

11 daunting   

adj.使人畏缩的

参考例句：

• They were faced with the daunting task of restoring the house.他们面临着修复房子的艰巨任务。
• Starting a new job can be a daunting prospect.开始一项新工作有时会让人望而却步。

12 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。