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The Sneaky Birds

2008-05-30

中学科技 2008年5期
关键词:行家体格脑子

Some birds are masters of crime. These sneaky species stealfoodfromotherbirds, andgetaway withit. A diverse collection of birds is guilty of such thievery, and scientists have long wondered what these families of birds have in common.

A new study suggeststhat bigbody size does not predict bullying behavior. Instead, among other traits, it is the size of the birds' brains that matters most.

It is estimated that about 2 percent of the world's birds steal. That's 197 out of 9672 known bird species that have been seen stealing food from other bird species.

To learnmore aboutwhat makessome birdstend toward a life of crime, scientists analyzed 856 published reports of theft by onebirdfromanother. Theyfound some patterns among the behaviors of the birds they studied. For one thing, bird families that often steal tend to live in open environments such as ocean shores. There, theycaneasilysee the targets of theirattacks. Such bird families also tend to eat fish, mice, and other vertebrates instead of just insects. These meals are hard to catch, so they are tempting to steal.

Finally, such birds tend to have big brains in relation to their bodies. That may seem surprising, since human bullies are often thought to be stronger in size than in smarts. But for birds, stealing isn't about body strength. It takes a clever bird to get food out of another hungry bird's claws, especiallyif thatbird isbigger than you are.

鸟中的偷窃行家

有些鸟儿是犯罪行家。这些偷偷摸摸的鸟类会从别的鸟儿那里偷取食物,然后逃走。有这种偷窃行为的鸟有许多不同的种类。科学家们长期以来一直想弄清楚这些鸟类有什么共同点。

一项新的研究发现,体型大并不意味着就会强横霸道。与其他特征相比,倒是鸟脑的大小与此最有关系。

据估计,全世界鸟类中有2%有偷食行为。也就是说,在已知的9672种鸟类中,有197种曾被人看见从其他鸟类那里偷过食物。

为弄清楚是什么驱使有些鸟去过犯罪生涯,科学家们分析了856份已经发表的有关鸟类偷窃的报道。结果发现他们所研究的鸟的行为有几种模式。首先,经常偷窃的鸟类往往居住在开阔的环境里(如海滨)。

在那里,它们轻而易举地就能看到它们想要袭击的目标。同时,这类鸟往往是吃鱼、老鼠和其他脊椎动物的,而不是光吃昆虫的。这些食物捕捉起来比较困难,因此它们就冒险去偷。

最后,这种鸟的脑子与它们的身体相比比较大。这一点看上去可能有点奇怪,因为一般认为强横霸道的人体格比较强大而并非脑子聪明。但对于鸟类来说,偷窃靠的不是体格强壮。要从别的饥饿的鸟(尤其是比自己大的鸟)的爪子下把食物搞到,这只鸟必须相当聪明。(注意斜体词的译法)

Britain's Fastest Supercomputer Unveiled

A supercomputer that could help answer some of science's biggest questions will be unveiled soon in Britain. With the power of 12,000 desktop personal computers, the mammoth machine called HECToR is the country's fastest computer and oneof themost (A) p ____in Europe. Itcan make 63 million calculations each (B) s_____, allowing scientists to conduct research into everything from climate (1) c_____ to new medicines. That supercomputer is (C) h ________in 60 wardrobe-sized cabinets inthe University ofEdinburgh'sadvanced computingcentreneartheScottishcapital. Afteryearsofdevelopment, Chancellor Alistair Darling is due to attend the official launch (D) c______ for the 113 million pound machine.

"HECToR will enable usto do (E) r______ that we simply could not do in any other way," saidJane Nicholson, ofthe Engineeringand Physical Sciences ResearchCouncil, thepublicbody which actsastheproject'smanaging agent. "We want to push (2) f______ the boundaries of knowledge."

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