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Hawaiian Crows Ready for the Call of the Wild

一度濒危的夏威夷乌鸦又将返回自然啦

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

很久以前，在夏威夷大岛上听到乌鸦叫是司空见惯的事：

[wild Hawaiian crow call]

(野生夏威夷乌鸦的叫声)

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.

那就是夏威夷乌鸦的叫声。夏威夷乌鸦是一种极度濒危物种，由于数十年来遭遇栖息地丧失、农民迫害和疾病侵袭，现在已经在野外灭绝了。20世纪90年代中期，野生动物生物学家把极少数幸存下来的乌鸦聚集在一起，将它们纳入一个圈养繁殖计划。今天，夏威夷人可以再次听到100多只夏威夷乌鸦（亦称'alalā）的叫声了，不过只能在鸟舍才能听到。

\[aviary³ crow call]

(鸟舍乌鸦的叫声)

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

研究人员曾经把主要精力集中在繁殖和饲养上。但是现在他们需要了解更多了。

"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."

“现在，它们表现得非常好，是时候可以再次在野外生存了，所以我们可以对们的声音和行为等进行研究了。”

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.

夏威夷大学生物研究所的研究员谷本安说道。可以说，对像夏威夷乌鸦这种具有社会复杂性的物种来说，文化等其他方面至关重要。

Tanimoto and her team made recordings⁴ 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.

谷本和她的团队录下了夏威夷火山的凯奥霍鸟类保护中心圈养乌鸦的叫声，然后同美国渔业与野生动物局的生物学家在上世纪90年代录下的声音进行了比较。

"The wild have more, almost double the number of alarm calls, than the aviary 'alalā do. And they also have these really cool territorial⁵ broadcast calls they do in the wild

“与圈养的乌鸦相比，野外乌鸦的报警鸣叫次数几乎多了一倍。而且它们在野外还会发出非常酷的领土广播鸣叫。

[Wild territorial call]

(野外的领域号声)

that weren't found in captivity⁶."

而圈养乌鸦则没有发出过这种叫声。”

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.

圈养乌鸦没有领域号声完全说得通，因为圈养乌鸦同野生乌鸦有不同的领土要求。另外，圈养乌鸦的报警鸣叫次数更少，因为它们不会经历捕食的威胁，所以这也可以说得通。这项研究结果发表在《动物行为》杂志上。

"So we think that their vocalizations that are similar, aviary and wild, are more innate⁷, so basically naturally inside of them. And those that differ are socially learned by being passed on generation to generation."

“所以，我们认为圈养乌鸦的发声和野生乌鸦的发声很相似，这更多是与生俱来的，可以说是天生的。而那些不同的声音是通过代代相传的社会学习演变而来的。”

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

那当圈养繁殖的鸟类被释放到大自然中会发生什么?它们并没有机会从祖先那里学习这些叫声。

"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 previously⁸."

“确定它们是否会开始发出同此前在野外生活时类似的声音，或者它们是否会开始发出与在野外生活时完全不同的声音，一定会是非常有趣的事。”

In Hawaiian mythology⁹, 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.

在夏威夷神话中，认为夏威夷乌鸦能将灵魂引导至卡拉也火山附近的最终安息之地。幸运的是，科学家可以帮助这种珍稀物种不用去往卡拉也。