我们终于解开了为什么这只无聊的鸟有这么多五颜六色的小鸡的奥秘

我们终于解开了为什么这只无聊的鸟有这么多五颜六色的小鸡的奥秘

The American coot is a ubiquitous bird often seen waddling across the surfaces of North America's ponds and lakes. Their plumage is rather forgettable; a plain-black coloring that often blends with the murky waters where it swims.

美洲白骨顶是一种常见的鸟类，经常可以在北美的池塘和湖泊表面看到它摇摆的身影。它们的羽毛很容易被遗忘;一种纯黑色，经常与它游泳的浑浊的水混合在一起。

Why are coot chicks so much flashier than adults? (Photo: Casey Klebba/Wiki Commons [CC 4.0 License])

This unadorned look is all a ruse, however. Coots are hiding some rather mischievous behavior under that boring veneer, and while the adults can hide it well, it's written all over the feathers of their chicks, reports Phys.org.

然而，这种不加修饰的打扮完全是一种诡计。据Phys.org报道，白骨顶在无聊的外表下隐藏着一些相当淘气的行为，虽然成年白骨顶可以很好地隐藏这些行为，但这些行为却写在了雏鸟的羽毛上。

Scientists have long been befuddled by the discrepancy between the colors displayed by coot chicks and coot adults. Unlike their parents, chicks are born with fiery-orange feathers, beaks, and skin. Their flamboyancy seems to go against common evolutionary logic. Usually, colorful plumage in birds is utilized as a mating display; better-ornamented adults (most often males) are more likely to attract mates, and thus pass down their genes to the next generation.

科学家们一直对白骨顶雏鸟和成年白骨顶的颜色差异感到困惑。与它们的父母不同，小鸡出生时羽毛、喙和皮肤都是桔红色的。他们的浮夸似乎违背了普遍的进化逻辑。通常，鸟类的彩色羽毛被用作求偶展示;装饰得更好的成年人(通常是雄性)更有可能吸引配偶，从而将他们的基因传给下一代。

But that can't be what's happening with coot chicks, because they lose their colors by the time they reach sexual maturity. Furthermore, chicks are typically more vulnerable to predators than adults are, so shouldn't that brilliant colorization make them even more susceptible to catching the eye of a hungry carnivore?

但那不可能是发生在白骨顶雏鸟身上的事，因为它们在性成熟时就会失去颜色。此外，雏鸟通常比成鸟更容易受到捕食者的攻击，所以鲜艳的色彩难道不应该使它们更容易被饥饿的食肉动物盯上吗?

But now, scientists think they've solved the mystery, and the explanation hints at these birds' hidden wild side.

但是现在，科学家们认为他们已经解开了这个谜团，而且这个解释暗示了这些鸟类隐藏的野性的一面。

In a new study published in Proceedings of the National Academy of Sciences, researchers explain how coot chick ornamentation was found to correlate with the order in which those chicks hatched. Coot hens lay about ten eggs, one per day, and the eggs usually hatch in the order in which they were laid. It turns out that the later a chick hatches, the more colorful it is.

在《美国国家科学院院刊》上发表的一项新研究中，研究人员解释了如何发现白骨顶小鸡的纹饰与这些小鸡孵化的顺序有关。白骨顶母鸡每天产大约10个蛋，蛋通常是按它们产蛋的顺序孵出来的。事实证明，小鸡孵得越晚，颜色就越鲜艳。

Why should this weird correlation exist? The researchers realized it was a clue. For one, it indicates that it's not the chicks who are 'choosing' their colors, it must be their mothers.

为什么会存在这种奇怪的相关性?研究人员意识到这是一个线索。首先，这表明不是小鸡“选择”它们的颜色，而是它们的妈妈。

"That tells us the chicks can't be controlling their coloration, because they don't know where they are in the laying order. This is a maternal effect, presumably due to the mom putting more carotenoid pigments in the later eggs," explained Bruce Lyon, first author of the new study.

“这告诉我们，小鸡不能控制它们的颜色，因为它们不知道它们在产卵顺序中的位置。这项新研究的第一作者布鲁斯·里昂解释说:“这是一种母性效应，可能是由于母亲在后来的鸡蛋中添加了更多的类胡萝卜素。”

Further observation of coot nesting and laying behavior helps to reveal why it might be useful for coot mothers to color-code their chicks. Turns out, coots utilize a roguish parental tactic known as brood parasitism. They lay a number of eggs in the nests of other coots in an effort to fool them into raising their chicks for them. They typically do this with the first few eggs that they lay, reserving the later eggs for their own nests.

对白骨顶筑巢和产卵行为的进一步观察有助于揭示为什么对白骨顶母亲来说用颜色给雏鸟编码是有用的。事实证明，白骨顶利用了一种被称为幼体寄生的顽皮亲代策略。它们会在其他白骨顶的巢里下很多蛋，试图愚弄它们，让它们替自己喂养雏鸟。它们通常会在刚下蛋的时候这样做，把后来的蛋留到自己的巢里。

So, the color coding can help them to identify which chicks are more likely to be their own, and not the orphans of some other sneaky coot. Researchers confirmed this strategy by noting how coot parents tend to pick favorites, making sure that the most colorful chicks are also the best fed.

因此，颜色编码可以帮助它们识别哪些小鸡更有可能是自己的，而不是其他一些狡猾的白骨顶的孤儿。研究人员通过观察白骨顶父母倾向于挑选最喜欢的品种来证实这一策略，以确保色彩最鲜艳的雏鸟也能得到最好的喂养。

Coot breeding is a labyrinthine world, where these drab birds hide their true colors, secretly attempting to pull one over on each other.

白骨顶繁殖是一个迷宫般的世界，在那里这些单调的鸟隐藏他们的真实面目，秘密地试图把对方拉过来。

"They're complicated birds. For over 20 years, we've been chipping away at understanding their reproductive behavior, and this is another interesting aspect of that," Lyon said.

“他们复杂的鸟类。20多年来，我们一直在研究它们的繁殖行为，这是其中另一个有趣的方面。”里昂说。

Further research into the genetics of this strategy should help to reveal the evolutionary logic behind it. How often are coots tricked into favoring chicks that aren't their own? The color-coding fail-safe must falter sometimes, otherwise it wouldn't make much sense for coots to go through with the whole bait-and-switch game to begin with.

对这种策略的遗传学的进一步研究将有助于揭示其背后的进化逻辑。白骨顶有多少次被骗去喜欢不是自己的小鸡?颜色编码故障保险有时必须动摇，否则通过整个诱饵和开关游戏开始，它将没有多大意义。

At the very least, the research shows that these birds have a lot more going on than their appearance might first suggest.

至少，研究表明，这些鸟比它们的外表看起来要复杂得多。