世界上最危險(xiǎn)的鳥是如何長(zhǎng)出它獨(dú)特的羽毛的

世界上最危險(xiǎn)的鳥是如何長(zhǎng)出它獨(dú)特的羽毛的

It's been called the world's most dangerous bird. Its long dagger-like toes, in fact, were responsible for the death of a man in Florida last year.

它被稱為世界上最危險(xiǎn)的鳥。事實(shí)上，它那像匕首一樣的長(zhǎng)腳趾導(dǎo)致了去年佛羅里達(dá)州一名男子的死亡。

But what excites scientists about the cassowary — a large, emu-like, flightless bird — is its distinctive look. With its black iridescent feathered body, its blue, turquoise and magenta neck and horned crest, it's been described as looking like a "high-fashion dinosaur."

但是，讓科學(xué)家們興奮的是，這種大型的、類似鴯鹋的、不會(huì)飛的食火鳥有著與眾不同的外表。它有著黑色夾著彩虹色的羽毛身體，藍(lán)色、藍(lán)綠色和洋紅色的脖子，以及有角的羽冠，被形容為“高級(jí)時(shí)尚恐龍”。

"It's a little over a meter tall. It's pretty heavy. Their bones are dense. They definitely can cause some damage," said Chad Eliason, a staff scientist and postdoctoral fellow at the Field Museum in Chicago and an author of a new paper on the giant bird that published Wednesday in the journal Science Advances.

“它有一米多一點(diǎn)高。它很重。它們的骨骼很致密。它們肯定會(huì)造成一些損害，”查德·埃利亞松說。他是芝加哥菲爾德博物館的研究員和博士后，周三在《科學(xué)進(jìn)展》雜志上發(fā)表了一篇關(guān)于這種巨型鳥類的新論文。

"There's lots of stories about dangerous kicks with their claws. They help you to realize birds are related to dinosaurs."

“有很多關(guān)于用危險(xiǎn)的爪子踢人的故事。它們幫助你認(rèn)識(shí)到鳥類和恐龍是有聯(lián)系的。”

Each of its three-toed feet has a claw that can be up to 4 inches or 10 centimeters long, allowing it to slice open a predator with a single kick, according to the San Diego Zoo. It can also run up to 31 miles per hour through dense forest and jump up to 7 feet (2 meters).

根據(jù)圣地亞哥動(dòng)物園的說法，它的三趾腳各有一個(gè)長(zhǎng)達(dá)4英寸或10厘米的爪子，可以一腳踢開捕食者。它還可以在茂密的森林中以每小時(shí)31英里的速度奔跑，跳躍高度可達(dá)7英尺(2米)。

High gloss

高光澤

New research on the feathers taken from a dead bird has now revealed what gives cassowary feathers their glossy black shine.

對(duì)取自一只死鳥的羽毛的最新研究現(xiàn)在已經(jīng)揭示了是什么使食火雞的羽毛呈現(xiàn)出光滑的黑色光澤。

"Understanding basic attributes — like how colors are generated — is something we often take for granted in living animals," said paleontologist Julia Clarke, a professor at the Jackson School of Geosciences at the University of Texas at Austin and the paper's senior author.

德克薩斯大學(xué)奧斯汀分校杰克遜地球科學(xué)學(xué)院教授、該論文的資深作者、古生物學(xué)家朱莉婭·克拉克說:“了解基本屬性——比如顏色是如何產(chǎn)生的——是我們通常認(rèn)為了解活的動(dòng)物應(yīng)該具備的(知識(shí))。”

"Surely, we think, we must know everything there is to know? But here, we started with simple curiosity. What makes cassowaries so shiny?"

“當(dāng)然，我們認(rèn)為，我們必須知道所有該知道的事情嗎?但在這里，我們從簡(jiǎn)單的好奇心開始。是什么讓食火雞如此閃亮?”

Unlike in other shiny birds, such as hummingbirds or crows, the cassowary's glossiness is produced by the rachis, or the spine of the feather, rather than the barbules, or minute filaments fringing a feather.

與其他有光澤的鳥類，如蜂鳥或?yàn)貘f不同，食火雞的光澤是由羽軸或羽毛的脊柱產(chǎn)生的，而不是由羽枝或羽毛邊緣的細(xì)絲產(chǎn)生的。

Since the fluffy barbules on cassowary feathers are pretty sparse, the rachis gets more exposure to light than in "thick-feathered" birds, giving it a chance to literally shine.

由于食火雞羽毛上蓬松的羽枝相當(dāng)稀疏，因此與“厚羽毛”鳥類相比，羽軸能接觸到更多的光線，這就給了它真正閃亮的機(jī)會(huì)。

"The gloss is in a totally different part (compared to other birds). You picture a feather being like a tree, the gloss is in the trunk of the tree, not the branches," Eliason explained.

“與其他鳥類相比，這種光澤是完全不同的。你想象一根羽毛就像一棵樹，光澤在樹干上，而不是樹枝上，” 埃利亞松解釋說。

The study suggested that the cassowary's unique gloss-producing mechanism would have evolved gradually over time, with an ancestral bird losing its barbules and the cassowary developing a thicker central feather shaft.

這項(xiàng)研究表明，食火雞獨(dú)特的產(chǎn)生光澤的機(jī)制會(huì)隨著時(shí)間的推移逐漸進(jìn)化，一只祖?zhèn)鞯镍B失去了它的羽枝，而食火雞進(jìn)化出了更厚的中央羽毛軸。

Eliason suspected that flightlessness might have given cassowaries more evolutionary room to develop their odd-shaped feathers.

埃利亞松懷疑，沒有飛行能力可能給了食火雞更多的進(jìn)化空間來發(fā)展它們的奇形怪狀的羽毛。

"Losing that constraint, that need to fly, might result in new feather morphologies that produce gloss in a way that a flying bird might not."

“失去這種約束，即需要飛翔的約束，可能會(huì)導(dǎo)致新的羽毛形態(tài)，以一種飛行的鳥類可能不會(huì)的方式產(chǎn)生光澤。”