你見過會叫的蜘蛛嗎?
These spiders can purr
這種蜘蛛能發出低沉的聲音Wolves howl to let others know that they're around - and maybe even that they are looking for a mate. But not the wolf spider known as Gladicosa gulosa. It makes a kind of a purr. It's quite a trick for guys of this species. And that's because it's not clear that the target of their attentions can actually hear a purr. A female may just feel the effects of that sound as vibrations in her feet. But even that may not happen unless both he and she are standing on the right surface.
狼通過嚎叫的方式告知周圍它們的存在，甚至還會用這種方式求偶。但一種被稱爲Gladicosa gulosa的狼蛛則不然，它們會發出一種低沉的咕嚕聲，對於這種生物來說這樣做也的確算得上是一項獨門祕技。因爲他們所關注的目標實際上能否聽見其低鳴尚不清楚，或許雌蜘蛛只能感覺到雄蜘蛛發出聲音時在它們腳底下產生的振動，可是當他們沒有站在合適的平面上時雌蛛可能連振動都感覺不到。
How the spider purrs
蜘蛛如何發出低鳴聲？
At mating time, male wolf spiders try to catch a female's attention by creating "persuasive" vibrations, Sweger says. They strum one structure on their body against another - somewhat as a cricket does - to impress the gals. Getting the message right can be a matter of life and death to the guy who's doing the wooing. If the female isn't totally convinced that he's the "one," it could be worse than just being rejected, Sweger explains. "She could eat him." About one out of every five male wolf spiders will be eaten by the female he had been wooing. But the guys who prove suitably persuasive will get to mate - and live to tell the tale.
求偶時雄性狼蛛會使出渾身解數用"勸誘"的振動方式吸引雌性狼蛛的注意，他們用身體的一部分拍打另一部分發出震動聲（就像蟋蟀一樣），而後給雌蜘蛛留下印象。Sweger表示能否正確收到求愛信息關係着求愛者的性命，如果雌蜘蛛沒能被完全說服他就其 "真命天子"，那麼雄蜘蛛的情況有可能比被拒絕還要糟糕，他可能會被她吃掉。這並不稀奇，因爲每五個雌性狼蛛中就有一個被他們的所追求的另一半吃掉。但如果事實證明雄蜘蛛的確有勸誘能力，那麼他們最終將會得到交配的機會，並向配偶講述他們悲慘的"浪漫際遇"。Purring spiders "are using the same vibratory tactics as every other wolf spider in North America. More or less," Sweger says. "They're using the same structures. And they're making vibrations."But the scientists showed that compared to the wooing vibrations made by other wolf spiders, those by Gladicosa gulosa are far stronger.
Swege稱在北美這種能發出低吟聲的蜘蛛或多或少使用的都是和所有其他狼蛛一樣的振動技巧。它們使用的是同樣的身體結構來產生振動。但科學家表示，與其他發出求愛振動信號的狼蛛相比，這種名爲Gladicosa gulosa的狼蛛的振動更加強烈。Sweger discovered something else as well. When a purring spider was on a surface that is good at conducting vibrations, such as leaves, an audible sound was produced.
Sweger還發現了其他一些東西。當一隻低吟的狼蛛處在更有利於傳導振動的位置，比如說樹葉上時它們會發聲音。If a person is within a meter of the courting spiders, they can actually hear the sound. "It's very soft, but when we're out in the field, you can hear them," Sweger says. The sound, he explains, is a bit like a "little strumming chirp" or a "soft rattle or purr." (You can judge for yourself.)
Sweger表示當一個人距離一隻正求偶的狼蛛僅一米時，他會聽到這種聲音，和柔和。但當我們在野外時，你也會聽到它的聲音. 這種聲音類似於有節奏的唧唧聲，或者是那種柔和的咯咯聲、咕嚕咕嚕的聲音等等（這就得靠你自己判斷了）。
