60秒科学:利用录音发现青蛙的数量可能被高估了

Frog census¹ volunteers misinterpreted recorded frog sounds in the field, leading researchers to suspect that frog populations may be even lower than thought.

Declining frog populations are considered an indicator³ of environmental damage. But new research finds that frogs might be doing even worse than we thought. Because the volunteers who count frogs by their sounds may be overestimating⁴.

The North American Amphibian⁵ Monitoring Program is the country’s largest frog-counting system. Volunteers listen for frogs, identify the species, and give population estimates. They’ve been doing this for over a decade.

Ted² Simons from North Carolina State University and colleagues put recordings⁶ of frogs, like this wood frog, [Wood Frog sound] in the field to test the volunteers. They call it Ribbit Radio.

Many volunteers ended up with false positives—they named frog species whose calls weren’t being played. So there may be fewer frogs, or less variety, than the surveys suggest. The results appear in the journal Ecology.

Simons is working with the U.S. Geological Survey—in charge of the amphibian monitoring—to account for these false positives, and to better train the volunteers—so they don’t write down “chorus frog” [Chorus Frog sound] when all there really was were pickerel frogs. [Pickerel Frog sound] Apparently, it’s not easy being green, for humans either
 

1 census   

n.(官方的)人口调查，人口普查

参考例句：

• A census of population is taken every ten years.人口普查每10年进行一次。
• The census is taken one time every four years in our country.我国每四年一次人口普查。

2 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。

3 indicator   

n.指标；指示物，指示者；指示器

参考例句：

• Gold prices are often seen as an indicator of inflation.黃金价格常常被看作是通货膨胀的指标。
• His left-hand indicator is flashing.他左手边的转向灯正在闪亮。

4 overestimating   

对（数量）估计过高，对…作过高的评价( overestimate的现在分词 )

参考例句：

• I think you're overestimating his abilities. 我看你对他的能力评价过高。
• With hindsight, he was overestimating their desire for peace. 事后看来，他高估了他们对和平的渴望。

5 amphibian   

n.两栖动物；水陆两用飞机和车辆

参考例句：

• The frog is an amphibian,which means it can live on land and in water.青蛙属于两栖动物，也就是说它既能生活在陆地上也能生活在水里。
• Amphibian is an important specie in ecosystem and has profound meaning in the ecotoxicology evaluation.两栖类是生态系统中的重要物种，并且对环境毒理评价有着深远意义。

6 recordings   

n.记录( recording的名词复数 )；录音；录像；唱片

参考例句：

• a boxed set of original recordings 一套盒装原声录音带
• old jazz recordings reissued on CD 以激光唱片重新发行的老爵士乐