经济学人下载:远古动物行为 侏罗纪雨燕

Science and technology
科学技术

Ancient animal behaviour
远古动物行为

Jurassic lark
侏罗纪雨燕

How the pterosaur caught its supper
翼龙是如何逮到晚餐的

PALAEOETHOLOGY, working out how long-extinct animals behaved, is a subject whose practitioners can never, definitively, be proved right.
古行为学，作为一门研究那些早已灭绝的动物的行为的学科，其研究者永远不可能证明自己的理论是确凿无误的，

But that does not stop them trying.
但这一点从来没有阻止过他们对真相的探索。

The latest effort, to be presented later this month to the International Symposium on Pterosaurs in Rio de Janeiro, is an attempt by Michael Habib of the University of Southern California, in Los Angeles, and Mark Witton at the University of Portsmouth, in Britain, to work out how one of the most peculiar of the flying reptiles of the Jurassic earned its living.
本月晚些时候，将于里约热内卢举行的国际翼龙目研讨会将展示该领域最新一项研究成果，南加州大学的Michael Habib和普利茅斯大学的Mark Witton进行了该项研究，目的在于弄清楚侏罗纪最神奇的飞行类爬行动物之一是如何捕捉食物的。

Anurognathus and its relatives have been known for 90 years.
蛙嘴龙及其近亲为人类了解已有90年。

They were the size of swifts and until now it had been thought that, like swifts, they chased around the sky after insects—a technique known as hawking.
它们体型如雨燕般大小，直到今天，人们一直认为它们像雨燕一样在天空中到处疾飞追逐昆虫—即一种被称为飞行捕食的摄食策略。

Dr Habib and Dr Witton believe this is wrong.
两位博士Habib 和Witton认为这种理论是错误的，

They suspect instead that Anurognathus sat in wait for its prey, and then sallied forth to intercept it like a surface-to-air missile.
他们猜想蛙嘴龙反而是静待猎物，然后像地空导弹一样突然腾空截击。

They came to this conclusion by comparing Anurognathus with 36 birds and 20 bats from the Smithsonian Institution in Washington, DC.
在将蛙嘴龙与取自斯密森学会博物馆的36种鸟和20种蝙蝠进行对比后，Habib和Witton做出这一推论。

Using a mix of computerised tomography and mundane measurements with callipers, they assessed the lengths, widths, thicknesses, densities and bending potential of the bones of the modern animals and compared them with those gleaned from Anurognathus fossils.
他们综合了计算机断层摄影术和使用卡钳的普通测量方法，分析评估了现代动物骨骼的长度，宽度，厚度，密度及弯曲度可能性，并将它们和从蛙嘴龙化石中搜集到的数据进行对比。

Anurognathus's mouth, they found, was similar to the mouths of nightjars, which also sally after prey.
他们发现，蛙嘴龙的嘴与夜鹰相似，后者也是突袭猎物的。

Moreover, the pterosaurs' legs and wings were stronger than those of any comparable bird or bat, reinforcing the idea that they could leap rapidly into the air.
另外，翼龙的腿和翅膀要比任何可以相提并论的鸟类和蝙蝠都要强壮，这一点强化了它们可以迅疾腾空的观点。

Their conclusion was that Anurognathus did indeed feed by sallying—and probably more effectively than any living creature.
两位博士Habib和Witton的结论是，蛙嘴龙的确是突然腾空袭击猎物的—而且它们的狩猎有可能比任何生物都要更高效。