鳥類如何長途跋涉，飛越海洋和陸地？科學家離揭開這個謎團又近了一步。

Scientists studied the robin – a familiar garden bird that can sometimes migrate – flying alone, at night and often over great distances. They identified a magnetically sensitive molecule in the bird’s eye, known as a cryptochrome, that could form the basis of the in-built magnetic compass birds may use to navigate.

科學家們研究了知更鳥，一種經常可以在自家花園見到的鳥類，它有時會遷徙，在夜晚獨自翱翔，而且經常長途飛行。這些科學家在知更鳥的眼睛里發現了一種對磁場非常敏感的分子，被稱為隱花色素。鳥類可能借助體內的磁羅盤導航，而這種隱花色素也許就是構成磁羅盤的基本元素。

Professor Peter Hore at the University of Oxford says it could be that birds can ‘see’ the Earth’s magnetic field, although they don’t know that for sure.

牛津大學的彼得·霍爾教授說，這也許是因為鳥類可以 “看到” 地球的磁場，不過科學家們還不能完全確定這一點。

The researchers are planning further studies to investigate how birds, and perhaps other animals, might use this living compass in their epic migrations.

研究人員正在計劃進一步研究鳥類甚至其它動物是如何利用這種 “活羅盤” 來進行壯觀的大遷徙的。

詞匯表

migrate 遷徙
magnetically 磁力地
molecule 分子，微粒
compass 羅盤，指南針
magnetic field 磁場
epic 壯觀的

閱讀理解：請在讀完上文后，回答下列問題。

1. Where are robins often seen?

2. Where is the molecule, the ‘cryptochrome’, located?

3. What could this new molecule help robins do?

4. True or false? This cryptochrome molecule is limited only to birds.

答案  

1. Where are robins often seen?
Robins are a familiar garden bird.

2. Where is the molecule, the ‘cryptochrome’, located?
The molecule known as the ‘cryptochrome’ is located in the eye.

3. What could this molecule help robins do?
It could form the basis of the in-built magnetic compass birds may use to navigate.

4. True or false? This cryptochrome molecule is limited only to birds.
False. The researchers are planning further studies to investigate how birds and perhaps other animals might use this molecule.