美国国家公共电台 NPR Scientists Glued Fake Caterpillars On Plants Worldwide. Here's What Happened

 

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Sometimes good research can get done with a tool so simple a child could do it. For instance, scientists around the world recently set out thousands of fake caterpillars² made from clay. NPR's Nell Greenfieldboyce explains why.

NELL GREENFIELDBOYCE, BYLINE³: If you've got a preschooler at home who makes little worms out of Play-Doh, you should easily be able to imagine the fake caterpillars that scientist Tomas Roslin was putting out in Greenland. He wanted to know a little critter's risk of getting eaten. And this is an old technique.

TOMAS ROSLIN: Somebody came up with it, like, decades ago.

GREENFIELDBOYCE: He says of a bird or lizard⁴ or whatever tries to bite the caterpillar¹, telltale beak⁵ or tooth marks get left in the soft clay. Trouble is, at his research sites up north, it wasn't working.

ROSLIN: We tried it one summer, and very few of them ever got eaten.

GREENFIELDBOYCE: He's a researcher at the Swedish University of Agricultural Sciences, and he talked about his problem with another scientist, Eleanor Slade at the University of Oxford⁶.

ROSLIN: My friend Eleanor told me that, oh, she has been using the same technique in Borneo, and everybody gets eaten.

GREENFIELDBOYCE: The pair realized that maybe the risk of getting eaten, at least if you're a caterpillar, is actually higher in the tropics than near the poles. To test this idea, they enlisted⁷ 40 researchers in 21 countries from the Arctic Circle to southern Australia, including Liz Nichols, a biologist at Swarthmore College. She was doing research in Brazil.

LIZ NICHOLS: And then a box arrived with bright green gummy-looking caterpillars.

GREENFIELDBOYCE: Her team glued them onto leaves using glue and instructions that came in the box. A few days later, they shipped them back to a central lab.

NICHOLS: I mean it sounds kind of like child's play, I realize. But this kind of massive, simple, standardized⁸ technique is really powerful when you can implement⁹ it at a global scale in a really well-replicated way.

GREENFIELDBOYCE: Biologists Will Petry with the Swiss Federal Institute of Technology set out his dummy¹⁰ caterpillars at field sites in California. He was eager to be part of this study.

WILL PETRY: We've known for a really long time that there are more species in the tropics than there are in polar regions, but we don't have as good an idea of the geography of interactions between species.

GREENFIELDBOYCE: What the scientists found was a striking pattern. If you're a caterpillar at the equator, your chance of getting attacked by a predator¹¹ is much higher than it would be if you were closer to the poles - about eight times higher. Petry says all of this could help explain why certain creatures do what they do.

PETRY: There are some migratory¹² butterfly species like the monarch¹³, and one reason that they might migrate could be to avoid predators¹⁴.

GREENFIELDBOYCE: A detailed¹⁵ analysis of these results, a far cry from child's play, appears in the journal Science. Nell Greenfieldboyce, NPR News.

1 caterpillar   

n.毛虫，蝴蝶的幼虫

参考例句：

• A butterfly is produced by metamorphosis from a caterpillar.蝴蝶是由毛虫脱胎变成的。
• A caterpillar must pass through the cocoon stage to become a butterfly.毛毛虫必须经过茧的阶段才能变成蝴蝶。

2 caterpillars   

n.毛虫( caterpillar的名词复数 )；履带

参考例句：

• Caterpillars eat the young leaves of this plant. 毛毛虫吃这种植物的嫩叶。
• Caterpillars change into butterflies or moths. 毛虫能变成蝴蝶或蛾子。 来自辞典例句

3 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。

4 lizard   

n.蜥蜴，壁虎

参考例句：

• A chameleon is a kind of lizard.变色龙是一种蜥蜴。
• The lizard darted out its tongue at the insect.蜥蜴伸出舌头去吃小昆虫。

5 beak   

n.鸟嘴，茶壶嘴，钩形鼻

参考例句：

• The bird had a worm in its beak.鸟儿嘴里叼着一条虫。
• This bird employs its beak as a weapon.这种鸟用嘴作武器。

6 Oxford   

n.牛津（英国城市）

参考例句：

• At present he has become a Professor of Chemistry at Oxford.他现在已是牛津大学的化学教授了。
• This is where the road to Oxford joins the road to London.这是去牛津的路与去伦敦的路的汇合处。

7 enlisted   

adj.应募入伍的v.（使）入伍， （使）参军( enlist的过去式和过去分词 )；获得（帮助或支持）

参考例句：

• enlisted men and women 男兵和女兵
• He enlisted with the air force to fight against the enemy. 他应募加入空军对敌作战。 来自《现代汉英综合大词典》

8 standardized   

adj.标准化的

参考例句：

• We use standardized tests to measure scholastic achievement. 我们用标准化考试来衡量学生的学业成绩。
• The parts of an automobile are standardized. 汽车零件是标准化了的。

9 implement   

n.(pl.)工具，器具；vt.实行，实施，执行

参考例句：

• Don't undertake a project unless you can implement it.不要承担一项计划，除非你能完成这项计划。
• The best implement for digging a garden is a spade.在花园里挖土的最好工具是铁锹。

10 dummy   

n.假的东西；(哄婴儿的)橡皮奶头

参考例句：

• The police suspect that the device is not a real bomb but a dummy.警方怀疑那个装置不是真炸弹，只是一个假货。
• The boys played soldier with dummy swords made of wood.男孩们用木头做的假木剑玩打仗游戏。

11 predator   

n.捕食其它动物的动物；捕食者

参考例句：

• The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
• Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴，它是一种令人恐惧的捕食性动物。

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。

13 monarch   

n.帝王，君主，最高统治者

参考例句：

• The monarch's role is purely ceremonial.君主纯粹是个礼仪职位。
• I think myself happier now than the greatest monarch upon earth.我觉得这个时候比世界上什么帝王都快乐。

14 predators   

n.食肉动物( predator的名词复数 )；奴役他人者（尤指在财务或性关系方面）

参考例句：

• birds and their earthbound predators 鸟和地面上捕食它们的动物
• The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》

15 detailed   

adj.详细的，详尽的，极注意细节的，完全的

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。