BBC News:考拉為何愛抱樹

Now, have you ever wondered why koalas hug trees? And apparently, according to a new scientific study it is to stay cool. That discovery was made by researchers from the University of Melbourne who were looking at how koalas regulate their body temperature.

你曾想過為什么考拉抱樹嗎?根據(jù)最新科學研究表明，顯然考拉抱樹是為了保持涼爽。這項研究是墨爾本大學的科研人員在觀察考拉如何調(diào)節(jié)自身體溫時發(fā)現(xiàn)的。

And one of my students Natalie Briscoe, her PHD was focused on this question in terms of the koala. And one of the questions we want to ask about the koala is, do they use behavior at all to regulate their temperature, are they able to choose places in their trees that make them a bit more comfortable.

我的一名學生納塔莉·布里斯科的博士論文就是集中研究考拉的這個問題的，而且也是我們都想要問的問題，考拉們是完全用行為來調(diào)控它們的體溫嗎?它們有能力在它們的樹上選擇能讓他們舒服點的地方嗎?

And how did you go about finding this out?

那么，你們是怎樣發(fā)現(xiàn)這點的呢?

Well, initially we went about this by putting a little weather station on a very long pole and lifting that weather station right up next to the koalas that we had radio transmitters on, and at the same time going around to other random places in their habitat and measuring the conditions in the trees of those locations. But what Natalie noticed was that the koalas in the hot weather would come down and will go to the thicker trunks. And they would flop onto those trunks and drop them limbs there. And we couldn't quite understand why they were doing that, but she also sought to measure the tree trunk temperatures and we found that they are actually quite a bit cool than the air. And then we took a special kind of camera that takes pictures of heat and tells us the temperature of every service in the picture. And it was so obvious once we got those pictures back. What the koalas were doing? They were putting their bottoms into the trees and dumping all their excess heating to the tree.

剛開始時，我們先要在長竿上安裝上小型氣象站，舉到考拉身邊，因為先前我們已經(jīng)在考拉身上也安裝了無線電發(fā)射器。同時，隨機選取考拉棲息地的其他地方的其他樹木來測定其他其他樹木的狀況。但是納塔莉注意到，在炎熱天氣下，考拉會從樹上爬下來，選擇更粗的樹干，跳上去，抱住這些樹干。我們剛開始時并不理解它們?yōu)楹芜@樣做，但是納塔莉努力檢測到了樹干的溫度，并發(fā)現(xiàn)樹干的溫度其實稍稍低于氣溫。然后，我們選用特殊照相機，拍下顯示樹干熱量的照片，照片上顯示出每一個照片里的樹干的溫度。我們把這些照片拍攝回來，一切就一目了然了?？祭降资窃谧鍪裁茨?考拉把自己的身體緊貼樹木是為了把多余的熱量傳給樹木來保持自身的涼爽。

And were you surprised by what you found because it's known or presumably zoologists know that the fur on the stomach of the koalas is a lot thinner than it is elsewhere.

你對這一發(fā)現(xiàn)感到驚訝嗎?因為我們知道，或者說動物學家們知道，考拉腹部的皮毛要比身體其他不為薄的多。

Yeah, well, we knew that and we thought, well, maybe they, I guess one idea was that they just expose that during the hot weather so that heat comes out their chests into the air. What we didn't realize was how much cooler the tree trunks were than the air temperature.

是的，我們知道，可能我們大家會想到考拉們只需要在炎熱的天氣中直接把腹部露出來，把熱量通過腹部直接傳到空氣中就好了。而我們沒有意識到的是樹干的溫度要比空氣溫度低很多。

That wasn't obvious to us. It was obvious when we looked at the trees with the special camera, but it wasn't before that. And then it made a whole lot of sense. And it's really surprised a lot of biologists.

我們開始也沒有太注意到這一點。直到我們用特別相機拍攝后才發(fā)現(xiàn)的，之前并不是很明顯。使用特殊相機拍攝后才真正明白所有，而且這也讓很多生物學家大吃一驚。

And it's always eucalyptus trees, is it?

考拉抱的總是桉樹嗎?

No, it's not. And not all eucalyptus trees is good as each other for this purpose, so we measure a whole, a few different species of eucalypts in their habitat where we did the study and also another kind of tree called acacia. And it turned out that the acacia was actually the best one. But they don't eat the leaves of the acacia trees, they only eat the leaves of the eucalypt trees.

不，不是的。并非所有的桉樹都適合考拉來抱，所以我們在考拉棲息地作了一項研究，所有的樹木中有幾種不同的桉樹類型，還有另一種樹名叫刺槐，并且研究證明刺槐是最適合考拉的。但是考拉們不吃刺槐樹葉，只吃桉樹葉。