好英语网乌鸦可能是除灵长类外最聪明的动物
The crow’s name was Betty. And she was on her way to stardom. A gaggle of Oxford University scientists watched in wonder as she casually picked up a piece of wire in her cage and then used a nearby object to bend it at one end, transforming the wire into a hooked tool. That tool allowed Betty to hoist up a small container of meat – delicious pig’s heart – from inside a plastic tube. Lunch was served.
这只乌鸦的名字叫贝蒂。她这次表演使她名扬天下。一群牛津大学的科学家惊奇地看着她随意抓起笼子里的一根铁丝，然后用附近的一个物体把铁丝的一端弄弯曲，把这只铁丝做成了一个钩子。最后贝蒂用这个钩子从一个塑料管中掏出一小包肉——美味的猪心，於是开餐享用她的午饭。
Back then, in 2002, Betty’s feat was a source of amazement. How did this crow solve such a complex problem so spontaneously? It suggested mental acrobatics akin to our own. This, the headlines read, was one stunningly clever crow.
我们再讲回2002年贝蒂那次的惊人表演。这只乌鸦是如何随机应变地解决如此复杂的问题? 其惊人之举似乎意味这只乌鸦的精神活动与我们人类相近似。当时媒体的新闻标题即称之为“聪明绝顶的乌鸦”。
乌鸦显示有能力解决其在大自然中不会遭遇到的高级难题。
Except that Betty was not quite as special as some first thought. Many years later, research showed that New Caledonian crows are habitual tool-benders. In the wild, they do it all the time. Observers had initially been startled by Betty’s behaviour because it looked as though she had come up with the design for her hooked tool on the fly. Like an engineer inventing a new machine. In reality, New Caledonians have evolved to make hooked tools from soft twigs as part of their usual foraging activity.
只是后来人们发现贝蒂并不像最初想象的是一只特殊的乌鸦。许多年后，研究发现新喀里多尼亚乌鸦都习惯弄弯树枝做钩子。这种乌鸦在野外经常这样幹。一开始，观察者被贝蒂的行为吓了一大跳，因为看起来她的工具钩子好像是她独自设计想出来的，其行为就像一个人类工程师发明了一种新机器一样。事实上，新喀里多尼亚乌鸦用柔软的小树枝制作钩形工具是这个物种进化衍生出来的天性，是它们日常觅食行为的一种本能。
It was less a moment of genius – and more an expression of her nature.
与其说这是一个天才乌鸦的表演，不如说这是贝蒂觅食的天然本性。
“I don’t want to downplay her cognitive abilities,” says Christian Rutz at the University of St Andrews. “At the very least, it forces us to reassess how insightful Betty’s behaviour was.”
圣安德鲁斯大学的克里斯蒂安·鲁兹说，“我不想贬低贝蒂的智力。至少，这可以迫使我们重新评估贝蒂的行为有多么聪明。”
New Caledonian crows belong to the corvid family of birds – as do jackdaws, rooks, jays, magpies and ravens. In recent years, the brains of these birds have been studied ever more closely. There is no doubt that some of them display impressive cognitive abilities. But intelligence is a murky subject. What exactly is it, in the first place? And why has it evolved?
新喀里多尼亚乌鸦是属于鸦科的一种鸟。属于鸦科的还有寒鸦、白嘴鸦、松鸦、喜鹊和渡鸦等。近年来，对鸦科鸟类大脑的研究越来越深入。毫无疑问，鸦科中某些类乌鸦的确表现出令人印象深刻的智力行为。但智力是一个含义模糊不清的题目。首先，所谓的鸦科鸟类的智力到底是什么?其次，为什么这种鸟类会进化出智力?
Corvids are helping us to answer these questions.
鸦科鸟类正在帮助我们回答这些问题。
Intelligence is rooted in the brain. Clever primates – including humans – have a particular structure in their brains called the neocortex. It is thought that this helps to make advanced cognition possible. Corvids, notably, do not have this structure. They have instead evolved densely packed clusters of neurons that afford them similar mental prowess.
智力来自于大脑。聪明的灵长类动物，包括人类，在大脑中有一种特殊的结构，叫做新皮层。人们认为就是新皮层使得高级智慧成为可能。显然，鸦科鸟类没有这种结构，而是进化出密集的神经元簇。正是这种神经系统赋予鸦科鸟类类似的智力。
The specific kind of brain they have doesn’t really matter – corvids and primates share some of the same basic capabilities in terms of problem-solving and plasticity, or being able to adapt and change in the face of new information and experiences. This is an example of convergent evolution, where completely different evolutionary histories have led to the same feature or behaviour.
大脑结构的具体类型并不重要，鸦科动物和灵长类动物在解决问题和随机应变方面有一些相同的基本能力，在面临新信息和新状况时能作出适应的改变。这是趋同进化的一个例子。所谓趋同进化是指这样一种进化现象，即完全不同的物种，因处于相同的生态而进化出相同的特征或行为。
It’s easy for humans to see why the things corvids can do are useful. From identifying people who have previously posed a threat to them or others in their group to using gestures for communication – we too rely on abilities like these.
人类很容易明白为什么鸦科鸟类的智力行为于其生存是有用的，比如乌鸦能识别曾经对它们构成威胁的人类或它们群体的其他乌鸦，以及能使用身体姿势进行沟通交流等，因为我们人类也要依赖这些能力。
Rutz is unequivocal. Some birds, like the New Caledonian crows he studies – can do remarkable things. In a paper published earlier this year, he and his co-authors described how New Caledonians seek out a specific type of plant stem from which to make their hooked tools. Experiments showed that crows found the stems they desired even when they had been disguised with leaves from a different plant species. This suggested that the birds were selecting a kind of material for their tools that they knew was just right for the job. You wouldn’t use a spanner to hammer in a nail, would you?
鲁兹的研究很明确。有些鸟类，比如他所研究的新喀里多尼亚乌鸦，可以做出不同寻常的事情。在今年早些时候发表的一篇论文中，他和他的合著者描述了新喀里多尼亚乌鸦如何寻找一种特殊类型的植物茎干来制造他们的钩形工具。实验表明，乌鸦能找到它们想要的茎干，即使这些茎干被其他不同植物的叶子遮住。这说明，新喀里多尼亚乌鸦选择某种材料做钩子时，知道这种材料最适合做这项工作。就像人类，你不会用扳手去敲钉子吧?
In the wild, New Caledonians use their tools to scoop insects out of holes, for example in tree trunks. Footage of this behaviour has been caught on camera.
新喀里多尼亚乌鸦在野外用它们的工具把昆虫从洞里挖出来，例如树干上的洞。这种行为的视频已经被科学家用摄像机录了下来。
You might think that some animals are smarter than others – with humans at the top of the proverbial tree. Certainly, humans do rely excessively on intelligence to get by. But that doesn’t mean we’re the best at every mental task. Chimps, notes Dakota McCoy at Harvard University, have been shown to possess better short-term memories than humans. This might help them to memorise where food is located in the forest canopy, for example.
你可能会认为有些动物比其他动物聪明，而人类则位居这颗智力树的顶端。当然，人类确实过度依赖智力来生存。但这并不意味着人类在所有的脑力工作上都是最好的。哈佛大学的达科塔·麦考伊指出，黑猩猩已经被证明比人类拥有更好的短期记忆力。例如，这可能有助于黑猩猩记住食物在森林树冠层的位置。
Ranking the intelligence of animals seems an increasingly pointless exercise when one considers the really important thing: how well that animal is adapted to its niche. Intelligence is, first and foremost, a means towards specialisation.
如我们考虑到对物种最重要的能力是这一物种适应其生存环境的能力，那么，对动物的智力高低进行排序就是无意义之举。因为智力首先是物种为适应生存而演化出特定功能的手段。
As Rutz says, analysis of crows’ intelligence “cannot be divorced from the natural history of the animal”. And New Caledonians are far from the only non-human species to have evolved the ability to use tools. The list of other animals that share this trait includes chimpanzees, parrots, alligators and even crabs.
正如鲁兹所说，对乌鸦智力的分析“不能脱离动物的自然演化史”。新喀里多尼亚乌鸦远非唯一进化出使用工具能力的非人类物种。其他具有这种特征的动物还有黑猩猩、鹦鹉、短吻鳄，甚至螃蟹。
While cognition may help a creature to do things required for survival in its own environment, other animals get by via other means. Where a crow uses mental abilities and tools to access hard-to-reach food, a giraffe simply stretches its long neck. Clever cogs just have another tool from evolution’s own toolbox.
虽然智力可以让一种物种做出适应环境的行为以助其生存，但其他动物通过其他方式一样获得生存之道。乌鸦利用脑力和工具来获取难以够到的食物，而对于长颈鹿，只需要伸展它的长脖子就够了。聪明的家伙乌鸦只是多了一个进化工具箱里的工具。
That said, “clever” animals can sometimes perform tasks beyond those strictly demanded by nature.
也就是说，聪明的动物有时能超额完成自然严格要求的任务。
In this clip from the BBC TV series, Inside the Animal Mind, Chris Packham watches a New Caledonian, nicknamed 007, solve an artificially constructed puzzle involving eight distinct steps.
在这段英国广播公司纪录片《动物会思考吗》(Inside the Animal Mind)的片段中，克里斯·帕克汉姆(Chris Packham) 观看了一个绰号007的新喀里多尼亚乌鸦如何解决一个人工构建，有八个步骤的谜题。
This seems to dwarf Betty’s humble hooked tool demo. A crow has now been shown to apply its cognitive abilities to advanced problem solving. It’s a situation the bird would never encounter in the wild, but it excels all the same. True, 007 had already learned how the individual steps worked but solving them in sequence presents an even greater challenge. It’s a hint that this bird can plan ahead to some extent. There are likely many other fascinating things that 007 and his fellow crows can do, we just haven’t tested for them yet.
这个解谜过程似乎使贝蒂简陋的钩形工具演示相形见绌。这已证明乌鸦可以将其认知能力用于解决高级问题。谜题情景是这只乌鸦在野外永远不会遇到的，但它仍然很出色地解开了谜题。诚然，这八个步骤的每个单独步骤007早已经学会，但如要解决谜题必须按顺序一步一步来，这是更大的挑战。这暗示这只乌鸦可能在某种程度上已事前做了计划。007和它的乌鸦同胞或许还能做很多其他有趣的事情，只是我们还没有进行测试而已。
McCoy, like Rutz, also studies New Caledonian crows. In a paper published this year, she and colleagues described an experiment designed to show if the birds’ mood were affected by tool use. New Caledonians were trained to recognise that a box at one end of a table contained more food than a box at the opposite end. Then, the crows were presented with a box in the middle of the table – suggesting an uncertain quantity of meat inside.
麦克可伊（McCoy）和鲁兹一样，也在研究新喀里多尼亚乌鸦。在今年发表的一篇论文中，她和同事描述了一项实验，该实验旨在显示这种乌鸦的情绪是否受到工具使用的影响。新喀里多尼亚乌鸦经过训练后认识到，桌子一端的盒子里装的食物比桌子另一端盒子里的多。然后，麦克可伊在桌子中间给乌鸦放了一个盒子，并暗示这个盒子中有数量不确定的肉。
Birds that had recently used tools to retrieve food from a container approached the mystery box more quickly than those that had not used tools. This indicated that tool use made the crows more optimistic, says McCoy.
实验结果发现，最近使用过工具从盒子中取出食物的乌鸦比那些没有使用过工具的乌鸦更快地接近这个神秘的盒子。麦克可伊说，这表明使用工具使乌鸦对能够获取到食物的期望比较乐观。
That’s not to say they were necessarily “happy”, she adds – but it does suggest a positive relationship between tool use and expectation.
她补充说，这并不是说他们一定是快乐的，但确实表明工具使用和期望值之间有正面的联系。
Cognition, says McCoy, can be fun. It opens a door to behaviour that isn’t necessarily essential for survival.
麦克可伊说，智力可以是有趣的。它打开了一扇门，让那些不一定对生存至关重要的行为得以存在。
Crows, in fact, might be like us not so much because they are clever (and so are we) but rather because they sometimes engage their cleverness simply for fun – and so do we.
事实上，乌鸦之所以像我们人类，并不是因为它们聪明，我们人类也一样，而是因为乌鸦有时运用其智慧只是为了好玩，而我们也是一样。
The crows McCoy studies have a natural curiosity, she says. They cheekily grab scientific equipment and fly off with it in the aviary. Young birds especially, she says, love to play. Humans are not so different, she argues: “We have these incredibly huge brains but we use them to do crossword puzzles – that’s not something that is evolutionarily selected for.”
麦克可伊说，她研究的乌鸦有一种天生的好奇心。他们会在鸟舍中，很顽皮地抓起科研设备飞走。她说，幼鸟尤其喜欢玩耍，这与人类没有那么不同。她指出，“我们人类有难以置信的巨大大脑，但我们常用这样的大脑来做填字游戏，这不是进化所选择的功能。”
One could argue that there are utilitarian benefits to such mental exertion. It keeps the mind sharp, it reinforces one’s abilities – all the fitter to survive. But if there is pleasure in it or if it has unexpected effects, one might also say that such activity is just part of what makes life colourful. New Caledonian crows, like us and other clever animals, have moods and memories. Strategies and expectations. They seem remarkably able to engage with complexity.
有人可能会说，这种脑力劳动自有其功能，可使头脑保持敏锐，增强一个人的能力，而所有这些都有利于生存。但是，如果此种脑力活动会产生乐趣或有意想不到的效果，人们也可能会说，这样的脑力活动只是让我们的生活变得丰富多彩的一部分。新喀里多尼亚乌鸦，像我们人类和其他聪明的动物一样，有情绪和记忆，有策略和期望。它们似乎非常善于处理复杂的事情。
Evolution made this possible. But cognition, like life itself, serves more than just a need. Animal intelligence allows all sorts of fascinating phenomena to arise. A gorilla that recognises human language. A crow that solves puzzles. A parrot that tells jokes.
进化使这成为可能。但是智力，就像生命本身一样，不仅仅是一种需要。动物的智力使各种迷人的现象得以出现。有能识别人类语言的大猩猩。有能解谜题的乌鸦。也有会讲笑话的鹦鹉。
Nature provided the notes, but animal brains make the music. The mind, as they say, is the only limit.
大自然提供了音符，是动物的大脑用这些音符制造了音乐。正如人们爱所说的，人类的心智才是唯一的极限。