课程咨询
托福培训

扫码免费领资料

托福全科备考资料

免费水平测试及规划

托福培训

扫码关注掌握一手留学资讯

回复XDF免费水平测试

科学美国人60秒:松鸦挑选食物先摇晃称重-托福听力下载

2017-01-24 16:53:00来源:科学美国人60秒

  科学美国人60秒中文翻译:

  If you've ever been to an all-you-can-eat buffet, you know how important it is to carefully weigh your options. 如果你去过任君吃到饱的自助餐,你就会明白仔细慎重食物的重要性。

  You don't want to fill up on salad when so many calorie-laden delights await. 在面前摆满满是高卡路里的美食时,你肚子里肯定不想全是沙拉。

  It seems some birds also weigh their mealtime choices—literally. 而从字面意思上讲一些鸟类也会这样选择自己的食物。

  A study finds that Mexican Jays pick up and shake peanuts to assess their relative heft before choosing one. 一项研究发现墨西哥松鸦在挑选坚果时会通过摇晃对其重量进行评估。

  That report is served up in the Journal of Ornithology. 这项研究已经在《鸟类杂志》上发表。

  Foods that hide their edible bits on the inside present a challenge to hungry diners. 某些食物的可食用部分是在其内部,因此对这些饿货们而言无疑是个难题。

  How can you tell which fruits are ripe or which shells harbor the biggest nuts? 你该如何分辨果实的成熟或哪个是最大的坚果呢?

  We humans knock on melons or squeeze avocados. 我们人类通常会通过在西瓜上拍拍或在牛油果上挤挤的方式挑选。

  But how do other species select the highest quality snacks? 但其它物种又是怎样选择呢?

  To find out how the jays do it, researchers fiddled with their feed. 为探究墨西哥松鸦的行为方式,研究人员在它们的食物中做了手脚。

  First they doctored peanuts so that some contained three nuts while others had none. 他们先下手的是坚果,使得一些坚果中有3粒果肉,另一些则一个也没有。

  When they offered these pods to some jays, the birds turned their beaks up at the empty shells and instead chose those that were full. 当这些坚果呈现在墨西哥松鸦面前时,它们用嘴去碰触那些空壳,然后选择了满满果肉的。

  And when the jays were allowed to choose between normal peanuts and those that weighed just one gram more, 而后这些墨西哥松鸦面对的是正常及重一克的坚果,

  because the researchers had stuffed them with clay, the birds again went for the heavier meal. 松鸦再一次选择了较重的坚果,因为研究人员在一些坚果涂上粘土使其比正常版本重一克。

  Videos revealed that the jays shake the nuts before selecting one, 视频显示墨西哥松鸦在选择时会先进行摇晃。

  which apparently lets them gauge the nut's mass and perhaps also listen for the rattle of a well-packed shell. 这样的动作能够判断坚果的重量,甚至倾听食物内部的声音。

  Pretty clever for a bird brain. 对鸟类而言这已经算是顶尖聪明了。

  以上就是新东方在线托福网为你带来的科学美国人60秒中英文文本翻译音频下载等资料,更多精彩敬请关注新东方在线托福网。

托福辅导

关注新东方在线托福

托福机经·Official题目练习

考前重点突破·听说读写海量资料

更多资料
更多>>
更多内容

免费获取托福备考大礼包

微信扫描下方二维码 立即领取

托福辅导
更多>>
更多公益讲座>>
更多>>
更多资料