不会飞的鸟

It's a biological mystery that has confounded scientists for over a century: How did the world's tiniest flightless bird find its way to one of the world's most remote islands?

世界上最小的不会飞的鸟，到底是怎样来到世界上最远岛之一的呢?这是困惑了科学家们一个世纪的生物学谜题。

The Inaccessible Island rail (Atlantisia rogersi), sometimes called the "bird from Atlantis," is only found in one place on Earth, the appropriately named Inaccessible Island in the South Atlantic Ocean, smack dab between Africa and South America. Because the bird is flightless, it's unclear how it could have found its way to such a far-flung place.

荒岛秧鸡(拉丁学名Atlantisia rogersi)，有时候也称“亚特兰蒂斯之鸟”，只在地球上的一个地方被发现过，该地在南大西洋，它有一个很合适的名字——难达岛，刚好位于非洲和南美之间。

When the bird was first discovered, scientists guessed that perhaps its ancestors walked to the island at a time when sea levels were lower and a land bridge stretched out across the Atlantic. This theory also became the basis for assigning the bird its own genus, Atlantisia, an homage to the mythical lost city of Atlantis which, according to legend, had also been swallowed by the sea.

当科学家们首次发现这种鸟类时，他们猜测也许是它们的祖先还在海平面低的时候，就沿着横跨在大西洋上的陆地桥走到了岛上。这个理论后来成为了将鸟归为秧鸡属的基础，传说是为了崇敬早已被海淹没的亚特兰蒂斯城的陨落。

But it now appears that this theory was mistaken. A new genetic analysis of the bird has revealed what its closest living relatives are, which has, in turn, provided some telling clues about how its ancestors may have found themselves in such a distant locale, reports Science Daily.

但现在看来这个理论好像是错误的。据科学日报报道，一项新的鸟类遗传分析已经揭晓了它们现存的最近亲属是谁，这也为它们的祖先是如何发现自己身处如此之远的岛上，提供了一些有效证据。

It turns out, this itsy-bitsy flightless bird probably got to Inaccessible Island by flyingthere about 1.5 million years ago. Of course, at that time it was not flightless; the bird likely evolved to become flightless as an adaptation to its remote habitat.

事实证明，这种迷你不会飞的鸟，很可能在约150万年前就飞到了这座难达岛上。当然那时它们还是会飞的，只是后来为了适应这种偏远栖息地，最后很可能就不会飞了。

Although the Inaccessible Island rail is certainly an oddity, the study found that it has a distant relation to the dot-winged crake in South America and the black rail found in both South and North America. These birds are adept flyers, known to colonize habitats far and wide.

虽然荒岛秧鸡的确很奇怪，但该研究发现，它和南美的点翅秧鸡，还有在南北美都发现过的黑田鸡有着深远的关系。这些鸟都很擅长飞行，也因“殖民”的栖息地广泛而闻名。

"It seems that rail birds are extremely good at colonizing new remote locations and adapting to different environments," explained evolutionary biologist Martin Stervander, who conducted the research.

主管该项研究的进化生物学家Martin Stervander这样说道：“秧鸡们好像非常擅长‘殖民’又新又远的地方，也很会适应不同的环境。

It might seem unusual for a bird so adept on the wing to ever give up the ability to fly for a life confined to the ground on a small island, but it's a fairly smart adaptation. Flying takes a lot of energy and resources, and resources aren't plentiful on small islands in the middle of an ocean. Furthermore, there are no land predators on Inaccessible Island, so there's no need for wings to escape. Instead, the bird is able to fill the niche that tiny rodents might occupy elsewhere, scurrying around through the vegetation.

对一只非常熟练飞行的鸟来说，放弃飞行，把自己限制在小小的一座岛屿上生活，真的很不寻常，但这确实是相当聪明的适应。飞行消耗大量能量和资源，而大海中的一片小岛上本来资源就不充足。再说，难达岛上没有陆地掠食者，所以也没必要需要翅膀逃亡。相反，这些鸟儿可以在植被中四处乱窜，以填补小的啮齿类动物为了占领每个地方所挖的坑。

"The bird has not had any natural enemies on the island and has not needed to fly in order to escape predators," said Stervander. "Its ability to fly has therefore been reduced and ultimately lost through natural selection and evolution over thousands of years."

Stervander说：“这些鸟在岛上还没有任何自然敌人，也不需要为了逃开掠食者而飞走，它们的飞行能力因此也就降低了，最终通过几千年的自然选择和进化失去了飞行的能力。”

So, mystery solved. But this bird is truly one-of-a-kind, the last surviving member of a lost lineage that somehow found its way to a very unlikely habitat, and its rarity underscores the importance of making sure that it's protected. For now, Inaccessible Island is relatively pristine, with few introduced species that might compete with the bird. It will be important for conservationists to ensure that it stays this way.

所以谜题解开了。但该鸟真的是世界上不知为何能够找到几乎不可能的栖息地的，快要灭绝的血统中，唯一，也是最后的幸存成员了。它们的稀少也意味着保护它们的重要性。现在，难达岛还相对原始，只是有一些可能和它们竞争的鸟类存在。对自然资源保护者来说，保持这个岛原本的样貌真的很重要。