什么是有袋動(dòng)物？袋鼠都吃些什么

今天的這段對話，在討論袋鼠，
 
什么是有袋動(dòng)物？袋鼠都吃些什么
 
來聽今天的講解:
 
A: What's your favourite animal? I like koalas the most.
 
你最喜歡什么動(dòng)物？我最喜歡的是考拉。
 
B: Funny you should say that, I like kangaroos. How very antipodean of us!
 
說起來還真有意思。我喜歡的是袋鼠。我們真是截然不同啊！
 
A: I think kangaroos are funny looking animals.
 
我認(rèn)為袋鼠的樣子看上去很好玩。
 
B: Kangaroos are part of a special category of animals, called marsupials.
 
它是一種特殊的動(dòng)物，叫做有袋動(dòng)物。
 
A: Kangaroos usually have small deer-like heads with wide set eyes and binocular vision, prominent upright ears which rotate to hear in all directions.
 
它的小腦袋象麋鹿，但眼睛大且雙眼都有視力，耳朵高高豎起，還可以轉(zhuǎn)動(dòng)以便聽到四面八方的聲音。
 
B: Yes, and a moderately long muzzle with a split upper lip, short forelimbs with mobile grasping forepaws that can hold food, open its pouch and box just like a boxer!
 
是的，它的口鼻長度中等，上唇裂開，前肢短小。它前爪靈活，可以抓事物，打開袋子，并且象拳擊手一樣打架。
 
A: They are very skilled at using their little arms! And when they have a little baby in the pouch it looks adorable.
 
它們還很善于運(yùn)用短臂！它們的育兒袋里放著小袋鼠時(shí)看起來非?？蓯?。
 
B: A joey.
 
一只幼獸。
 
A: A what?
 
一只什么？
 
B: A joey, that's what a baby kangaroo's called. Another interesting thing about them is their long hind limbs, with the characteristic long narrow feet which gives them the name of "macropod" or "big-foot".
 
一只幼獸，也就是小袋鼠。袋鼠的另外一個(gè)有意思的地方就是它們的后腿很長，而腳是又長又細(xì)，因此又被稱作“長腳”或“大腳”。
 
A: So, because they have short forelimbs and long hindlimbs, they can jump easily, quickly and for long distances.
 
正是因?yàn)榇笄爸芏潭笾趾荛L，所以它們才能跳得又快又遠(yuǎn)。
 
B: Right. Taking off on their hind feet, landing on their fore limbs and tail, pushing off again with their hind limbs. The elongated and very strong fourth toe of the hind foot serves as a lever to propel the animal along and bears the animal's weight when it stands.
 
沒錯(cuò)。袋鼠用后腳起跳，用前肢和尾巴著地，然后用他們的后肢推動(dòng)再次跳起。袋鼠后腳的第4個(gè)腳趾長而有力，作為向前跳時(shí)的支撐點(diǎn)，還承擔(dān)著自己站立時(shí)的體重。
 
A:I see. Long legs increase the stride when hopping. Forelimbs and tails prop them up when they crawl slowly to feed. Powerful hind limbs and a large heavy tail serve for balance and support.
 
我知道了。長腿使它們跳得更遠(yuǎn)，而緩慢爬行進(jìn)食時(shí)，它們的前肢和尾巴又起著支撐作用。它們強(qiáng)有力的后退和粗重的尾巴也起著平衡和支撐作用。
 
B: But tree kangaroos have shorter prehensile tails and climb rather than hop. Many kangaroo species are grazers and browsers adapted to living in dry desert habitats.
 
但是樹袋鼠的尾巴較短，有捕捉力，適合爬而不適合跳。許多袋鼠都是食草和嫩葉的動(dòng)物，喜歡四處覓食，適合在干旱的沙漠環(huán)境中生活。
 
A: Just like me! I'm always eating and gazing at what's going on around me. The desert is so dry, what can they eat?
 
就象我一樣！我總是一邊吃東西一邊注意觀察身邊發(fā)生的事。不過沙漠這么干，袋鼠都吃些什么呢？
 
B: They usually eat any grass they can find, even very hard grass.
 
能找到的所有草類，它們通常都吃，哪怕是那些很堅(jiān)硬難啃的草。
 
A: They must have food, strong teeth too.
 
它們的牙齒也一定都堅(jiān)硬耐磨。
 
B: Some, such as several tree kangaroos, my particular favourite, are threatened with survival, but others, like the grey and red kangaroos, have flourished and are now considered to be pests.
 
有些袋鼠，比如一些樹袋鼠，也是我最喜歡的那種，現(xiàn)在正瀕臨滅絕；但另外一些種類，比如紅袋鼠和灰袋鼠，現(xiàn)在因繁殖過多而被當(dāng)成禍害。