关注微信领¥50

百门课程¥0元


50万+已关注

科学美国人60秒:军舰鸟可连续飞行两个月-托福听力下载

2016-11-21 16:16:16来源:科学美国人60秒

点击查看>>科学美国人60秒音频:军舰鸟可连续飞行两个月

  科学美国人60秒中英文翻译:军舰鸟可连续飞行两个月

  科学美国人60秒英文文本

  This is Scientific American — 60-Second Science. I'm Julia Rosen.

  Got a minute?

  Great frigate birds are extraordinary creatures. They're seabirds with six-foot wingspans, yet they weigh only about three pounds. Their preferred food: flying fish—which they pluck out of the air above the water's surface. Frigate birds' feathers aren't waterproof, so landing on the water to fish is a no-go.

  Now, scientists have discovered that great frigate birds do something else amazing: they can fly for up to two months at a time without landing.

  Researchers already knew that these birds took extended trips over the Indian and Pacific Oceans to feed. But in a new study, scientists used tracking devices to follow the movement and vital signs of birds from the island of Europa, near Madagascar. They discovered that the birds have a highly specialized strategy for staying aloft.

  "When they are traveling, most of the time, they flap very infrequently their wings."

  Henri Weimerskirch, an ecologist at the National Center for Scientific Research in France.

  "In fact, what they are doing, they are doing sort of a roller coaster flight where they take altitude. Even they can climb up to 3,000 or 4,000 meters, and when they climb, they do not flap their wings at all."

  Weimerskirch and his colleagues found that the birds climb currents of rising air associated with cumulus clouds, circling upwards the way hawks and vultures do over land. Then they glide back down again, hardly flapping. By using atmospheric conditions to their advantage, the birds covered an average of 420 kilometers a day almost effortlessly. The study is in the journal Science.

  The researchers also discovered that the birds endure some harrowing conditions on their voyage, including some thrills and chills.

  "When you enter into the clouds, there's a lot of turbulence. After, when you see from the recording on the logger of the bird, when they are at 4,000 meters, the temperatures are negative. It's a tropical bird. It's a bird that has no specific down like geese that are operating in the Arctic. So they are encountering sort of a polar temperature, but it's a typical tropical bird."

  Of course, the birds have to eat during their journey. The researchers found that diving down to the sea surface to snatch a meal consumed most of the birds' energy, even though it only occupied about 10 percent of their time.

  "When they are climbing, they have a period where there is no movement at all during several minutes. And so, during this time is probably the time when they are sleeping."

  That's right—like many others who make long-distance flights, great frigate birds catch a little shut-eye along the way.

  Thanks for listening for Scientific American — 60-Second Science Science. I'm Julia Rosen.

  中文翻译请点击下一页

为你特别匹配的托福超值课程,快速提分先人一步!
  • 【留学TED】丢掉困扰,留学生活就该丰富多彩

    丢掉困扰,留学生活就该丰富多彩

    适合人群:留学党

    课时:1小时

    查看详情
  • 阅读营 – 扫清托福阅读长难句4大障碍

    阅读营 – 扫清托福阅读长难句4大障碍

    适合人群:备考托福阅读,攻克长难句的考生!

    课时:4小时

    查看详情
  • 1小时讲透托福(第2季:重难点解析)

    1小时讲透托福(第2季:重难点解析)

    适合人群:托福备考小白

    课时:4小时

    查看详情
  • 【活动价】新东方托福名师在线一对一(体验课)

    【活动价】新东方托福名师在线一对一(体验课)

    适合人群:想体验新东方在线致赢托福1对1辅导冲分课程的同学

    体验课时:30分钟

    查看详情
  • "美国大学直达号”系列公开课

    课程特点:留学考试专家与17位申请规划大咖带你直达梦校

    课时:8小时

    查看详情
全部课程>>
单项突破
直播课堂

更多托福课程
新东方25年教学经验沉淀
托福考生必修课
托福考生,高效提分,安心之选

查看详情>>
更多>>
更多课程>>
更多>>
更多内容
更多>>

TOEFL 20天扫清托福阅读长难句4大障碍

4天直播技巧讲解16天社群打卡学习

每周一小时直播,半小时答疑,4天12句长难句练习讲解,助你搞定托福长难句。 活动日期 : 2018.09.27-2018.10.31

价格 : ¥免费

675人 已报名

查看详情
更多>>
更多公开课>>
更多>>
更多课程>>