?Coquí frogs?are invasive species in Hawaii. But they don’t seem to bug the islands’ native and nonnative birds. Jason G. Goldman reports.Coquí?蛙是夏威夷的入侵物種。但是它們似乎不會影響島上的原生和外來鳥類。賈森·G·戈德曼(Jason G. Goldman)報道
? 撰文\播音:賈森·G·戈德曼(Jason?G?Goldman) 翻譯:張藝簫 審校:郭曉
? Coquí frogs. They’re named for the sound they make.?And though just an inch long, a coqui can produce a 90-decibel call—about the volume of a motorcycle 25 feet away. Coquí?蛙的名字由它們的叫聲得來。<聲音>盡管身長僅1英寸,coquí?蛙能發(fā)出90分貝的叫聲——相當于一輛距離25英里的摩托車發(fā)出的音量。 The animals and their nocturnal chirps are beloved in?their native Puerto Rico. But not in Hawaii, where they became invasive in the late 1980s. 這種動物和它們的“夜曲”在其原生的波多黎各很受歡迎。但在夏威夷卻并不如此,它們于二十世紀80年代晚期成為了夏威夷的入侵物種。 The frogs have become a nuisance in part because they cause people to lose sleep, which has actually driven down property values. But some of Hawaii's endangered insect species could face extinction due to the hungry invaders. Biologists also feared that the frogs could impact Hawaii's insect population to such an extent that native birds that also eat insects could go hungry. 這種青蛙已經成為當地公害,部分原因是它們導致人們失眠,進而降低了當地的房價。但是這些饑餓的入侵者可能會導致夏威夷的一些瀕危昆蟲物種滅絕。生物學家還擔心,這些青蛙可能會影響夏威夷的昆蟲數量,使得本地吃昆蟲的鳥類挨餓。 A group of researchers has now put that concern to the test by looking at thirty sites on the big island—half that were infested with coquís, and half that were still coquí-free. 一支研究團隊現在正在驗證這種擔憂,他們觀察了大島上的30個測試點,其中一半測試點有coquí?蛙入侵而另一半沒有。 "And we didn't see any response in the native birds. They seem to be doing fine with the coquís. At least their abundances were similar in places where there were coquís, and not coquís." “我們并沒有觀察到原生的鳥類有任何反應。它們似乎和Coquí?蛙相處融洽。至少在有coquí?蛙和沒有coquí?蛙的地區(qū),它們的數量沒有什么區(qū)別。” University of Utah ecologist Karen Beard. 猶他大學的生態(tài)學者Karen?Beard?說 "But it was the nonnative birds where we really saw the response. And we didn't see it in a negative way." “但是我們卻觀察到了非本地鳥類的反應。并不是負面反應。” Three types of nonnative birds were actually?more?abundant in areas with more frogs. 在coquí蛙更多的地方,三種非本地鳥的數量也更多。 "And we were like, huh. That's kind of interesting." “我們看到這個結果的反應就是:嗯,有點意思。” The researchers think they can explain this in two parts: coquís forage in leaf litter while Hawaii's native insect-eating birds forage in the canopy and understory, so they may be going after different types of prey. Meanwhile, the nonnative birds may be getting a boost by eating the frogs themselves. After all, a fingernail sized baby coquí frog is about the same size as a typical rainforest insect. The study is in the journal The Condor.?[Robyn L. Smith, Karen H. Beard, & David N. Koons.Invasive coquí frogs are associated with greater abundances of nonnative birds in Hawaii, U.S.A.] 研究人員認為它們可以從兩個方面解釋這種現象:coquí?蛙在落葉中覓食而夏威夷以昆蟲為食的原生鳥類則在樹冠層和下層植被中覓食,所以它們可能要找的獵物不一樣。與此同時,非本地鳥類可能通過吃掉青蛙,數量得以增長。畢竟,一個指甲大小的嬰兒coquí?蛙和一個典型的雨林昆蟲大小差不多。這項研究結果發(fā)表在《神鷹》(The Condor)雜志上?[Robyn L. Smith, Karen H. Beard, & David N. Koons.Invasive coquí frogs are associated with greater abundances of nonnative birds in Hawaii, U.S.A.]
? Despite these findings, coquí frogs could still harm Hawaii's native birds—indirectly. 除了這些研究結果之外,coquí?蛙還是會間接地傷害夏威夷的本地鳥類。 "If there's a lot more nonnative birds, there's a lot more nonnative bird nests. That could do something like increase rat and mongoose populations, which are known to be nest predators of native birds." “如果非本地鳥類大量增加,非本地鳥類的鳥巢也會大量增加。那可能會增加老鼠和貓鼬的數量,而老鼠和貓鼬是出了名的本地鳥類巢穴的捕食者。” Hawaii has stopped attempting to eradicate the big island of the invasive hoppers, where some spots may have 10 million coquis per square kilometer. Instead, the focus is on keeping them from expanding even further into the rainforest. To protect local species—and allow them to get some sleep. 夏威夷州已經停止試圖根除大島上的入侵跳躍者,然而島上的有些地方可能每平方千米有一千萬只coquí?蛙。取而代之,夏威夷著重防止coquí?蛙進一步入侵至雨林。這樣做是為了保護當地物種,也是為了讓當地人睡個好覺。