評論
打印
字號:
蜻蜓幼蟲可以感知捕食者的存在，雖然這使它們更加安全，但卻使它們的死亡率高于一般未感受到壓力的幼蟲。
A hungry fish can kill prey with a quick bite. That is, of course, if its prey hasn't already died of fright. Take tasty dragonflies. The mere presence of predators—even caged ones—is enough to scare dragonflies to death, according to a study in the journal Ecology. [Shannon J. McCauley, Locke Rowe, and Marie-Josée Fortin, "The deadly effects of ‘nonlethal’ predators"]
一條饑餓的魚能夠一口咬死其獵物。當然，前提是經過一番殊死搏斗之后獵物依然健在。以有趣的蜻蜓為例，根據《生物學》雜志的一篇研究報告，捕食者的出現能夠將蜻蜓嚇死，哪怕這些捕食者被關在籠子里面。 [Shannon J. McCauley, Locke Rowe, Marie-Josée Fortin, 《非致命捕食者的“致命”效果》]
Researchers collected wild dragonfly larva, and placed them in tanks with fish or insect predators. The larvae could see and smell their hunters—but were kept safe by underwater cages. After two months, the researchers took a head count—and found that dragonfly larvae sharing quarters with their killers were two to four times as likely to die off, compared to counterparts living in predator-free waters. And they had slimmer chances of surviving metamorphosis, too.
研究者將野生蜻蜓幼蟲放進裝有魚類或昆蟲類捕食者的容器中，具體的安放位置是在水下的籠子里，這里有絕對的安全保障，但同時幼蟲們也能夠看見并嗅到它們的天敵。兩個月之后，研究者發現，與捕食者同住的蜻蜓幼蟲死亡率是正常蜻蜓幼蟲的2-4倍。而且它們蛻變的存活率也更低。
The authors suggest a couple reasons why. First, prey tend to make fewer forays for snacks when predators are lurking around, so they may not be as nutritionally fit. And previous studies have shown that the presence of predators ups stress levels in prey, weakening their immune systems and making them more vulnerable to disease—and death.
文章的作者提出了幾點原因。首先，當有捕食者在場時，處于劣勢的被捕食者會減少覓食行為，所以它們的營養狀況不佳。加上之前的研究表明，捕食者的出現使被捕食者的壓力水平升高，降低了它們的免疫系統機能，使它們更易生病乃至于死亡。
As if being eaten wasn't enough to worry about, looks can kill too.
正所謂：死不足懼，怕死堪憂。看來生物界的規律是相通的。
mere n. 淺湖; 池 larva n. 幼蟲 counterpart n. 相應物 lurk v. 潛藏, 埋伏 nutritionally adv. 滋養地
收藏
