青蛙族群數(shù)量減少被認(rèn)為是環(huán)境遭到破壞的一項(xiàng)指標(biāo)。但是新的研究發(fā)現(xiàn)青蛙的實(shí)際情況或許要我們想像的還糟糕,因?yàn)橥ㄟ^蛙鳴來統(tǒng)計(jì)青蛙數(shù)量的志愿者很可能會(huì)把數(shù)字估計(jì)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
青蛙族群數(shù)量減少被認(rèn)為是環(huán)境遭到破壞的一項(xiàng)指標(biāo)。但是新的研究發(fā)現(xiàn)青蛙的實(shí)際情況或許要我們想像的還糟糕,因?yàn)橥ㄟ^蛙鳴來統(tǒng)計(jì)青蛙數(shù)量的志愿者很可能會(huì)把數(shù)字估計(jì)的高了。 北美兩棲類監(jiān)測(cè)計(jì)劃是美國最大的青蛙計(jì)數(shù)系統(tǒng)。志愿者們傾聽蛙鳴,鑒定其品種,并作出數(shù)量估算。十多年來,他們都是這么做的。 北卡羅來納州立大學(xué)的泰德?西蒙斯(Ted Simons)及其同事將蛙鳴錄了下來,好比現(xiàn)在播放的樹蛙的鳴聲,對(duì)志愿者們進(jìn)行實(shí)地測(cè)試。他們將其稱為Ribbit Radio。 許多志愿者最終報(bào)出的結(jié)果都有誤差——他們通過判斷蛙鳴而列出的蛙種其實(shí)并未在錄音中播放。因此,實(shí)際上的青蛙數(shù)量或是品種或許要比調(diào)查統(tǒng)計(jì)的數(shù)目少。該研究成果發(fā)表在《生態(tài)學(xué)》雜志上。 目前,西蒙斯與負(fù)責(zé)兩棲類監(jiān)測(cè)的美國地質(zhì)調(diào)查局合作來解釋這些誤報(bào)率,并對(duì)志愿者們進(jìn)行更好的訓(xùn)練,這樣他們就不會(huì)寫下“青蛙大合唱”而實(shí)際上是梭子蛙發(fā)出的鳴叫。顯然,綠皮膚的青蛙可不簡單,而人們?nèi)粝氤蔀榄h(huán)保先鋒亦非易事。