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科学美国人60秒 SSS Hawaiian Crows Ready for the Call of the Wild

时间:2017-03-06 07:09:26

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(单词翻译)

 

Once upon a time, on the big island of Hawaii, it would not have been unusual to hear: 

[wild Hawaiian crow call]

That’s the call of the Hawaiian crow. It’s is a critically endangered species, now extinct in the wild after decades of habitat loss, persecution1 by farmers, and invasive diseases. In the mid-1990s, wildlife biologists rounded up the few surviving crows and put them into a captive breeding program. Today, Hawaiians can once again hear the calls of more than one hundred Hawaiian crows – or 'alalā, as it is called there – but only in aviaries2.

[aviary3 crow call]

Researchers once focused their efforts primarily on breeding and husbandry. But now they need to know more. 

"And now that they are doing so well, and it's at the point where they could be in the wild again, now we can look at their vocalizations and their behaviors and things like that." 

University of Hawaii bioacoustics researcher Ann Tanimoto. Those other aspects—culture, if you will—are critical for a species as socially complex as the 'alalā.

Tanimoto and her team made recordings5 of captive-bred 'alalā pairs at the Keauhou Bird Conservation Center in Volcano, Hawaii, and compared them to recordings made in the early 1990s by Fish and Wildlife service biologists of the last few wild pairs.

"The wild have more, almost double the number of alarm calls, than the aviary 'alalā do. And they also have these really cool territorial6 broadcast calls they do in the wild 

[Wild territorial call]

that weren't found in captivity7."

The absence of the territorial call in captivity makes good sense, because captive birds have different territory demands that wild ones. It also makes sense that they would have fewer alarm calls, because captive birds don't experience the threat of predation. The study was published in the journal Animal Behaviour. [Ann M. Tanimoto et al.. Changes in vocal4 repertoire8 of the Hawaiian crow, Corvus hawaiiensis, from past wild to current captive populations.]

"So we think that their vocalizations that are similar, aviary and wild, are more innate9, so basically naturally inside of them. And those that differ are socially learned by being passed on generation to generation."

So what happens when the captive-bred birds are released? They won't have the luxury of learning these calls from their ancestors.

"It will definitely be interesting to determine if they will begin vocalizing something similar to those that they used in the wild before, or if they will begin vocalizing call types that are completely different than those that were in the wild previously10."

In Hawaiian mythology11, the 'alalā are thought to lead souls to their final resting place near the Ka Lae volcano. With luck, scientists can help the rare species avoid their own journey to Ka Lae.

—Jason G. Goldman


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1 persecution PAnyA     
n. 迫害,烦扰
参考例句:
  • He had fled from France at the time of the persecution. 他在大迫害时期逃离了法国。
  • Their persecution only serves to arouse the opposition of the people. 他们的迫害只激起人民对他们的反抗。
2 aviaries dd82791347ad47577ec23d089d79c8a3     
n.大鸟笼( aviary的名词复数 );鸟舍;鸟类饲养场;鸟类饲养者
参考例句:
  • Alarmed feathers from five aviaries of rare birds went flying. 说来说去,结果都没什么两样。 来自互联网
  • Tourists can find some aviaries, some cable cars and Water World there. 在那里游客们可以看到些鸟舍,一些缆车和水世界。 来自互联网
3 aviary TuBzj     
n.大鸟笼,鸟舍
参考例句:
  • There are many different kinds of birds in the aviary.大鸟笼里有很多不同种类的鸟。
  • There was also an aviary full of rare birds.那里面还有装满稀有鸟类的鸟舍。
4 vocal vhOwA     
adj.直言不讳的;嗓音的;n.[pl.]声乐节目
参考例句:
  • The tongue is a vocal organ.舌头是一个发音器官。
  • Public opinion at last became vocal.终于舆论哗然。
5 recordings 22f9946cd05973582e73e4e3c0239bb7     
n.记录( recording的名词复数 );录音;录像;唱片
参考例句:
  • a boxed set of original recordings 一套盒装原声录音带
  • old jazz recordings reissued on CD 以激光唱片重新发行的老爵士乐
6 territorial LImz4     
adj.领土的,领地的
参考例句:
  • The country is fighting to preserve its territorial integrity.该国在为保持领土的完整而进行斗争。
  • They were not allowed to fish in our territorial waters.不允许他们在我国领海捕鱼。
7 captivity qrJzv     
n.囚禁;被俘;束缚
参考例句:
  • A zoo is a place where live animals are kept in captivity for the public to see.动物园是圈养动物以供公众观看的场所。
  • He was held in captivity for three years.他被囚禁叁年。
8 repertoire 2BCze     
n.(准备好演出的)节目,保留剧目;(计算机的)指令表,指令系统, <美>(某个人的)全部技能;清单,指令表
参考例句:
  • There is an extensive repertoire of music written for the flute.有很多供长笛演奏的曲目。
  • He has added considerably to his piano repertoire.他的钢琴演奏曲目大大增加了。
9 innate xbxzC     
adj.天生的,固有的,天赋的
参考例句:
  • You obviously have an innate talent for music.你显然有天生的音乐才能。
  • Correct ideas are not innate in the mind.人的正确思想不是自己头脑中固有的。
10 previously bkzzzC     
adv.以前,先前(地)
参考例句:
  • The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
  • Let me digress for a moment and explain what had happened previously.让我岔开一会儿,解释原先发生了什么。
11 mythology I6zzV     
n.神话,神话学,神话集
参考例句:
  • In Greek mythology,Zeus was the ruler of Gods and men.在希腊神话中,宙斯是众神和人类的统治者。
  • He is the hero of Greek mythology.他是希腊民间传说中的英雄。

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