looks like nothing but a built-in baby sling.

看起來像什麼，但內置的嬰兒吊帶。

But if you peeked inside,

但如果你偷看裡面。

you'd see it's far more complex than a simple pocket.

你會發現這比一個簡單的口袋要複雜得多。

It has to be, because the joey inside

一定是的，因為裡面的喬伊...

is not your average baby.

不是一般的嬰兒。

An adult male red kangaroo can stand over

一隻成年的雄性紅袋鼠可以站立於

1 1/2 meters tall and weigh 90 kilograms.

高1.5米，重90公斤。

That's larger than a grown man.

這比一個成年男子還大。

But the newborns start out the size of jelly beans.

但新生兒一開始的大小就像果凍豆一樣。

They're blind, deaf, and hairless to boot.

他們是瞎子，聾子，沒有頭髮的引導。

After all, they only spend 33 days

畢竟，他們只用了33天

inside their mom before birth.

在他們的媽媽體內，在出生前。

That's like a human having a baby

這就像人類生孩子一樣

when she's two months pregnant.

當她懷孕兩個月的時候。

So the underdeveloped roo isn't ready to face

所以，發育不全的大鵬還沒有準備好面對

the harsh Australian wilderness.

嚴酷的澳洲荒野。

That's where the pouch comes in.

這就是小袋的作用。

It's a pocket of skin that acts like a second womb,

這是一個皮膚的口袋，就像第二個子宮。

giving the joey a safe, cozy environment to grow.

給喬伊一個安全、舒適的成長環境。

And, like a pregnant belly,

而且，像懷孕的肚子。

the pouch can stretch to fit the baby as it gets bigger.

袋子可以拉伸以適應寶寶長大後的需求。

It's lined with powerful,

它的內涵是強大的。

but flexible, muscles and ligaments.

但靈活，肌肉和韌帶。

To keep the joey safe, mom can tighten those muscles

為了保證喬伊的安全，媽媽可以收緊這些肌肉。

to shut the pouch flush against her body,

要把袋子齊刷刷地關在她的身上。

just like pulling a drawstring bag closed.

就像拉上一個拉繩包一樣。

And it will need the extra space,

而且它將需要額外的空間。

because over the course of eight months,

因為在八個月的時間裡，。

that bean-sized baby will reach the size

豆大的孩子會長大

of a large house cat.

的大型家貓。

That's thousands of times its birth weight.

那是它出生體重的幾千倍。

That rapid growth is thanks to the pouch's four nipples,

這種快速增長得益於小袋的四個乳頭。

which spout milk that contains germ-fighting antibodies

含有抗病菌抗體的牛奶。

to keep the little roo from getting sick.

以免小公雞生病。

But that's just the start.

但這僅僅是個開始。

You see, the nutrient levels change

你看，營養水準的變化

to meet the baby's needs as it ages.

以滿足寶寶年齡增長的需求。

For example, sulfur, a major building block of hair,

例如，硫磺，是頭髮的主要構成成分。

peaks around three months in.

在三個月左右達到高峰。

That's the same time the baby starts growing fur.

也就是寶寶開始長毛的時候。

The best part?

最精彩的部分？

Mom can produce multiple types of milk at the same time,

媽媽可以同時生產多種類型的牛奶。

each squirting from its own nipple.

每個人都從自己的乳頭噴出。

So she can suckle two babies

這樣她就可以給兩個孩子餵奶了

in different age groups simultaneously.

在不同年齡段同時進行。

Another special feature about the kangaroo pouch

袋鼠袋的另一個特色是

is that it's lined with sweat glands

是，它的內側有汗腺。

that release antimicrobial substances,

釋放抗菌物質的。

which help protect the baby roos

這有助於保護小公雞

from harmful viruses, bacteria, and parasites.

不受有害病毒、細菌和寄生蟲的侵害。

But there's one more way that pouch's design

但是，還有一種方式，小袋的設計。

keeps the joey safe.

確保喬伊的安全。

It's totally hairless, and that skin-to-skin contact

它完全沒有毛髮，而且皮膚與皮膚之間的接觸。

keeps the baby warm and cozy.

讓寶寶溫暖舒適。

Basically, it's the ultimate nursery.

基本上，它是終極的幼兒園。

But nothing lasts forever.

但沒有什麼是永遠的。

Eventually, the joey will need to leave the pouch.

最終，喬伊將需要離開這個袋子。

At about 5 months old, it pokes its head out.

在5個月左右的時候，它就會把頭探出來。

And a month later, it takes its first tentative

而一個月後，它第一次試探性地。

steps into the world.

步入世界。

There, it will explore for a few short seconds

在那裡，它將會探索幾秒鐘的時間

before high-tailing it home.

才高高興興地回家。

But as it gets older and bolder, it stays out longer,

但隨著年齡的增長，膽子也越來越大，在外面呆的時間也越來越長。

until eight months in:

直到八個月後。

It's ready to leave the nest, well, the pouch, for good.

它已經準備好離開巢穴了，嗯，是離開袋子，永遠離開。