红海龟也能辨识经度

作者:未知 来源:未知 2013-03-30

If you splashed down in the Atlantic, you'd flounder on which way to swim. But a hatchling loggerhead turtle would know just where to paddle—by reading the Earth's magnetic field. Scientists knew turtles can pinpoint latitude this way. Because the field varies a lot from north to south. But not east to west. So how do turtles know which side of the Atlantic they're on?
如果你掉进了大西洋,一定会为分不清方向而焦急不已。然而红海龟幼龟却知道该往哪里爬——通过辨识地球磁场。科学家知道海龟可以通过这种方式准确定位纬度。因为磁场由北至南变化很大。但是从东西向来看却并非如此。那么海龟怎样分辨自己在大西洋的那一侧呢?

To find out, researchers strapped hatchlings into custom Lycra bathing suits, tethered to a tracking unit. They plopped each turtle into a small pool surrounded by magnetic coils. And they replicated the magnetic fields of Puerto Rico and the Cape Verde Islands, two points along the turtles' migration, with equal latitudes but different longitudes. The hatchlings swam opposite directions in the two trials—both being the right ones, to stay on the migratory track. The study appears in the journal Current Biology. [Nathan Putman et al., "Longitude Perception and Bicoordinate Magnetic Maps in Sea Turtles"]
为了寻找答案,研究人员给海龟套上特制的莱卡泳衣,并附上跟踪装置。他们把每个海龟放进有磁线圈围绕的小池子里。模拟波多黎各和佛得角之间的磁场,这两地是海龟迁徙路线途经的两点,拥有同样的纬度但经度不同。在两次实验中位置不同的海龟选择了不同的方向,都成功找到了迁徙路线。这一研究发表在《当代生物学》期刊上。【Nathan Putman 等,“海龟的经度感知能力和双坐标磁力图”】

The researchers say turtles may calibrate their migratory maps by sensing the magnetic field's intensity, and its inclination to the Earth's surface—a combo that gives each point of the migration a unique signature. As for any human navigators out there, you'll just have to shell out for a GPS.
研究人员称,海龟可以通过辨识地球表面的磁场强度和磁场方向来校准自己的迁徙路线,这二者的结合使其迁徙路线上的每一点都有迹可循。而对于人类航海家来说,买个全球定位系统(GPS)足矣。

词汇解释

1. splash down vt. 溅落

2. hatchling n. 刚孵化的小动物

3. loggerhead n. 红海龟

4. pinpoint v.精确地找到

5. tether vt.拴住

6. plop v. 使扑通掉下, (扑通地)掉下

7. combo n.组合物

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