青蛙族群数量减少被认为是环境遭到破坏的一项指标。但是新的研究发现青蛙的实际情况或许要我们想像的还糟糕，因为通过蛙鸣来统计青蛙数量的志愿者很可能会把数字估计的高了。
Declining frog populations are considered an indicator 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 overestimating. The North American Amphibian 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. Ted Simons from North Carolina State University and colleagues put recordings 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. -Cynthia Graber
青蛙族群数量减少被认为是环境遭到破坏的一项指标。但是新的研究发现青蛙的实际情况或许要我们想像的还糟糕，因为通过蛙鸣来统计青蛙数量的志愿者很可能会把数字估计的高了。 北美两栖类监测计划是美国最大的青蛙计数系统。志愿者们倾听蛙鸣，鉴定其品种，并作出数量估算。十多年来，他们都是这么做的。 北卡罗来纳州立大学的泰德•西蒙斯（Ted Simons）及其同事将蛙鸣录了下来，好比现在播放的树蛙的鸣声，对志愿者们进行实地测试。他们将其称为Ribbit Radio。 许多志愿者最终报出的结果都有误差——他们通过判断蛙鸣而列出的蛙种其实并未在录音中播放。因此，实际上的青蛙数量或是品种或许要比调查统计的数目少。该研究成果发表在《生态学》杂志上。 目前，西蒙斯与负责两栖类监测的美国地质调查局合作来解释这些误报率，并对志愿者们进行更好的训练，这样他们就不会写下“青蛙大合唱”而实际上是梭子蛙发出的鸣叫。显然，绿皮肤的青蛙可不简单，而人们若想成为环保先锋亦非易事。