?Some Crows Hit On Dead Companions有些烏鴉會“勾引”已故的同類
? About 5 percent of crows will attempt to copulate with other crows that have joined the choir invisible. 有大約百分之五的烏鴉會試圖與已經(jīng)上了“天堂唱詩班”的同類交配。
? 撰文/播音 賈森?G?戈德曼(Jason G. Goldman) 翻譯?許楠 審校?張藝簫 Crows react really strongly to one of their own being dead—including gathering around their deceased comrades. Some experts believe that these so-called crow funerals are efforts to learn. Perhaps so they can avoid the same fate. ? 烏鴉對同類死亡的反應非常強烈——包括聚集在已故的同伴周圍。一些專家認為,這些所謂的烏鴉葬禮其實是它們在進行學習如何避免同樣的命運。 University of Washington researcher Kaeli Swift is one of those crow experts. When a film crew came to her campus to record these behaviors, Swift and her colleagues placed a dead crow on the grass. And they waited for the crows to show up and investigate. Just as they had done hundreds of previous times. 華盛頓大學的研究員凱利·斯威夫特(Kaeli Swift)是一名烏鴉專家。當一個電影攝制人員來到其學校記錄烏鴉的行為時,斯威夫特團隊在草地上放了一只死烏鴉,等待烏鴉出現(xiàn),并進行研究。就像之前做過的幾百次實驗一樣。 "The first bird came in, like they do, and I'm bracing myself for what I'm expecting to be the typical response. Which is that it alights in a tree, and it alarm calls, and then other birds come in…but instead what it does is it flies down to the ground, and it kind of walks up to the crow…but then it goes into really typical crow precopulatory posturing. Where basically they drop their wings down, and they stick their tails up, and they strut. And it just struts on over to the dead crow and jumps on top and copulates with it." “第一只烏鴉飛了進來,就像它們一樣,我也為將要見到意料之中的典型反應而激動。當在樹上發(fā)現(xiàn)地上的烏鴉后,它會發(fā)出警報,然后其他的烏鴉也會飛進來……它會飛到地面上,然后走到烏鴉那里……然后,它會變成典型的交配前的姿勢——把翅膀垂下來,尾巴翹起來,昂首闊步。它這樣走到死去的烏鴉身邊,跳上它的頭頂,和它交配?!?/span> Neither Swift nor her advisor had ever heard of this behavior. So they decided to determine just how common it is by conducting a series of experiments with wild crows in Seattle. They saw that most crows don't touch their dead—they observed physical contact roughly a quarter of the time. And sexual contact occurred less than five percent of the time. The finding is in the journal Philosophical Transactions of the Royal Society B. [Kaeli Swift & John M. Marzluff. Occurrence and variability of tactile interactions between wild American crows and dead conspecifics] 斯威夫特和她的導師都沒有聽說過這種行為。所以,他們決定在西雅圖對野生烏鴉進行一些的實驗,來確定這種現(xiàn)象的普遍性。他們發(fā)現(xiàn),大多數(shù)烏鴉不會觸碰同伴的尸體——只有大約有四分之一的時間,他們會觀察到它們有身體的接觸。性接觸發(fā)生的幾率不到5%。這一發(fā)現(xiàn)發(fā)表在《英國皇家學會哲學學報B》(Philosophical Transactions of the Royal Society B)雜志上[Kaeli Swift & John M. Marzluff. Occurrence and variability of tactile interactions between wild American crows and dead conspecifics]。 There's a twist that may be instructive: the crows' sexual behaviors were often combined with aggressive ones—not something that usually happens during mating encounters. And this was most frequent early in the breeding season. The researchers therefore wonder if some extremely hormonal crows may be unable to suppress one set of behaviors while expressing the other. 有一種可以解釋這一現(xiàn)象的聯(lián)系:烏鴉的性行為,通常與攻擊性行為結(jié)合在一起——但在交配時不常見。這一現(xiàn)象在繁殖季節(jié)的早期是最常見的。因此,研究員們想知道,是否有一些激素水平超高的烏鴉,在表達一種行為時,可能無法抑制另一種行為。 "Maybe these birds, because of these hormonal influences, are so incredibly territorial, they're so quick to take advantage of any opportunity for an extra-pair copulation, which is something we know crows engage in…but the part about this that makes it so exciting is we were actually able to quantify how frequent this behavior is. And that's completely brand new to science in any vertebrate animal." “也許這些烏鴉受激素的影響,領域意識異乎尋常的高,它們會快速的把握任何一個交配的機會,于是就出現(xiàn)了我們觀察到的事……而最令人興奮的是我們可以算出這種行為的頻率。對于任何脊椎動物研究來說,這都是全新的發(fā)現(xiàn)。 原文鏈接:https://www.scientificamerican.com/podcast/episode/some-crows-hit-on-dead-companions/