绿海龟是怎样在漫无边际的海洋中航行、找到阿森松岛的沙滩并在那里搭窝的？科学家们对它们的这一习性有了新的见解。

Every year between December and June, thousands of green sea turtles migrate. They go to Ascension Island to nest - females crawling ashore to lay their eggs in the sand. Because of the remote location and cost of research though, scientists still do not understand exactly how they get there.

每年12月到次年6月，成千上万只绿海龟迁徙。它们游到阿森松岛搭窝：雌龟爬上岸，在沙滩上挖坑产卵。然而，由于地点偏远和研究成本高昂，科学家们仍不清楚它们是如何到达那里的。

Now they've developed a model which simulates part of that arduous journey. What the scientists found is that the species uses a range of weak cues rather than a few strong ones, which could lead them off course. It makes sense - as relying on a single navigating cue, such as an inbuilt compass, could render them sensitive to change.

现在，他们研发出了一个模型来模拟绿海龟的那段艰辛征程。科学家们发现，该物种使用一系列微弱的线索来辨别方向，而不是靠可能引导它们偏离航线的大线索。这是有道理的，因为依靠单一的线索来定向，比如其体内的生物罗盘，可能使它们对变化十分敏感。

The scientists say that understanding how fish, animals and birds navigate could help them figure out how to protect those that are endangered, as well as what factors might affect their behaviour.

科学家们说，了解鱼、兽和鸟类的定向方式可以帮助他们弄清楚如何保护濒危动物以及哪些因素可能影响这些动物的行为。