神奇! 這種動物的便便竟然是方形的!

Scientists say they have uncovered how and why wombats produce cube-shaped poo -- the only known species to do so.

科學家們表示，他們發現了袋熊是如何以及爲何會拉方形便便的，這是已知的唯一一種會拉出方形便便的物種。

The Australian marsupial can pass up to 100 deposits of poop a night and they use the piles to mark territory.

這種澳大利亞有袋動物每晚可以拉多達100塊的大便，並使用這些糞堆來標記領土。

Despite having round anuses like other mammals, wombats do not produce round pellets, tubular coils or messy piles.

儘管有像其他哺乳動物一樣的圓形肛門，不過袋熊不會排出圓形顆粒、管狀圈形或一塌塌的糞便。

"The first thing that drove me to this is that I have never seen anything this weird in biology. That was a mystery," Georgia Institute of Technology's Patricia Yang said.

佐治亞理工學院的帕特麗夏·楊表示：“我從未在生物學上看到這麼奇怪的現象，這引起我的興趣。這是一個謎。”

After studying the digestive tracts of wombats put down after road accidents in Tasmania, a team led by Dr Yang presented its findings at the American Physical Society Division of Fluid Dynamics' annual meeting in Atlanta.

在研究了在塔斯馬尼亞被汽車撞傷並安樂死後的袋熊的消化道後，由楊博士領導的一個小組在美國物理學會流體動力學部門於亞特蘭大舉行的年會上介紹了其研究結果。

"We opened those intestines up like it was Christmas," said co-author David Hu, also from Georgia Tech, according to Science News.

據《科學新聞》報道，同樣來自喬治亞理工學院大衛·胡稱：“我們在聖誕節期間剖開了這些腸子。”

The team compared the wombat intestines to pig intestines by inserting a balloon into the animals' digestive tracts to see how it stretched to fit the balloon.

該團隊通過在動物的消化道中插入一個氣球，將袋熊的腸道與豬腸進行比較，看看它是如何伸展以適應氣球的。

In wombats, the faeces changed from a liquid-like state into a solid state in the last 25% of the intestines -- but then in the final 8% a varied elasticity of the walls meant the poop would take shape as separated cubes.

糞便在袋熊腸道最後25%的位置處從液體狀態變爲固態--但在最後8%的位置處，腸壁的彈性變化意味着大便會形成分離的立方體。

This, the scientists explain, resulted in 2cm (0.8in) cube-shaped poops unique to wombats and the natural world.

科學家們解釋稱，這就形成了2釐米（0.8英寸）的立方形糞便，這是自然界和袋熊獨有的特徵。

The marsupial then stacks the cubes -- the higher the better so as to communicate with and attract other wombats.

然後這種有袋動物會堆疊這些立方體，堆得越高越好，它們通過這樣的方式與其他袋熊交流並吸引其他袋熊。

"We currently have only two methods to manufacture cubes: We mould it, or we cut it. Now we have this third method," Dr Yang said.

楊博士表示：“我們目前只有兩種製造立方體的方法：模塑或切割。現在我們有了第三種方法。”