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.
鳥中的偷竊行家
有些鳥兒是犯罪行家。這些偷偷摸摸的鳥類會從別的鳥兒那里偷取食物,然后逃走。有這種偷竊行為的鳥有許多不同的種類??茖W(xué)家們長期以來一直想弄清楚這些鳥類有什么共同點。
一項新的研究發(fā)現(xiàn),體型大并不意味著就會強橫霸道。與其他特征相比,倒是鳥腦的大小與此最有關(guān)系。
據(jù)估計,全世界鳥類中有2%有偷食行為。也就是說,在已知的9672種鳥類中,有197種曾被人看見從其他鳥類那里偷過食物。
為弄清楚是什么驅(qū)使有些鳥去過犯罪生涯,科學(xué)家們分析了856份已經(jīng)發(fā)表的有關(guān)鳥類偷竊的報道。結(jié)果發(fā)現(xiàn)他們所研究的鳥的行為有幾種模式。首先,經(jīng)常偷竊的鳥類往往居住在開闊的環(huán)境里(如海濱)。
在那里,它們輕而易舉地就能看到它們想要襲擊的目標(biāo)。同時,這類鳥往往是吃魚、老鼠和其他脊椎動物的,而不是光吃昆蟲的。這些食物捕捉起來比較困難,因此它們就冒險去偷。
最后,這種鳥的腦子與它們的身體相比比較大。這一點看上去可能有點奇怪,因為一般認(rèn)為強橫霸道的人體格比較強大而并非腦子聰明。但對于鳥類來說,偷竊靠的不是體格強壯。要從別的饑餓的鳥(尤其是比自己大的鳥)的爪子下把食物搞到,這只鳥必須相當(dāng)聰明。(注意斜體詞的譯法)
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."