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Bird Beak¹ Shapes Depend on More Than Diet

The shape of the beaks² of different species of Galapagos finches played an important part in Darwin’s conception of natural selection.“In our field there is this presumption³ that the beak shape…in birds is quite correlated with what they eat and how they eat it. So, their feeding ecologies.”

加拉帕戈斯群岛不同种类雀喙的形状在达尔文的自然选择概念中起了重要作用。“在我们的研究领域，有这样一种假设:鸟类的喙形……与它们吃什么以及如何吃息息相关。”所以，它们的饮食生态。”

Guillermo Navalón, a PhD student at the University of Bristol in the U.K., and a co-author of a new study that found that the connection between beak shape and diet isn’t as tight as we thought. The study is in the journal Evolution.

吉尔莫·纳瓦隆，英国布里斯托尔大学的博士生一项新研究发现，喙形和饮食之间的联系并不像我们想象的那么紧密。这项研究发表在《进化》杂志上

Navalón and his colleagues analyzed⁴ photographs of museum specimens⁵ of 176 bird skulls⁶. They looked at beak shape and size in almost all of the orders of modern birds, and compared the beaks with other factors, such as feeding behavior and body size. And they found that the beak shape was indeed somewhat tied to what birds feed on and how they eat it—but the relationship was actually surprisingly weak, accounting⁷ for just 12 percent of beak shape variation.

纳瓦隆和他的同事分析了176个鸟类头骨标本的博物馆照片。他们研究了几乎所有现代鸟类的喙的形状和大小，并将喙与其他因素进行了比较，比如进食行为和体型。他们发现，鸟喙的形状确实在某种程度上与鸟类以什么为食以及它们如何进食有关——但这种关系实际上出奇地微弱，只占鸟喙形状变化的12%。

“The explanation that we extract from there is that the beaks are basically surrogate hands in the birds. They are used for a plethora⁸ of different functions beyond feeding ecology. Like the beak in general in birds have many other functions. So they use it for display, nest construction, singing, thermoregulation in some cases like toucans⁹ or like hornbills…so there is like a lot of factors that probably have intervened in the evolution of beaks in birds.”

“我们从中得出的解释是，喙基本上是鸟类的代理手。除了喂养生态外，它们还被用于许多不同的功能。就像鸟类的喙一般，还有很多其他的功能。所以他们用它来展示、筑巢、唱歌、调节体温，在某些情况下，比如巨嘴鸟或犀鸟……所以可能有很多因素影响了鸟类喙的进化。”