and they can see orange. |
能够看到橙色 |
[calling] |
|
[monkeys calling] |
|
[calling] |
|
[monkeys calling] |
|
The langur sounded the alarm before she could get close enough. |
雌虎还没有靠近 |
[panting] |
长尾叶猴就发出了警报 |
If the langurs can easily spot her, |
如果长尾叶猴能轻易发现它 |
why, then, is the tiger orange at all? |
那为什么老虎还要长成橙色? |
Why isn't she green? |
它怎么不长成绿色呢? |
That's because mammals are unable to develop green pigments, |
那是因为哺乳动物无法形成绿色色素 |
so it seems the next best solution for the tiger |
所以对于老虎来说 |
is to have orange fur, |
最好还是长出橙色的皮毛 |
which appears green to her main prey. |
这在它的主要猎物眼中 |
[growls softly] |
看上去是绿色 |
She will have to find a new target. |
它必须寻找新的目标 |
Down by the water, she finds one. |
顺着水流 它找到了一只 |
Sambar deer. |
水鹿 |
Sambar don't keep company with monkeys. |
水鹿没有猴群作伴 |
They are on their own. |
它们自力更生 |
They have the same limited eyesight as the chital, |
它们和白斑鹿一样 视力受限 |
but ears like satellite dishes. |
但是听力却像是卫星天线一样灵敏 |
If she treads on a twig and it snaps, |
如果雌虎踩到树枝 树枝折断 |
the hunt will be over before it began. |
这次捕猎就会在开始前便宣告失败 |
[snarls] |
|
[suspenseful orchestral music playing] |
|
The deer seem to sense danger. |
鹿群似乎感觉到了危险 |
They still can't see her. |
它们还看不见雌虎 |
[suspenseful orchestral music intensifies] |
|
[sambar bleats] |
|
[sambar calling] |
|
[water splashing] |
|
Despite her effective camouflage, |
尽管它伪装得很好 |
most hunts end like this. |
但大部分捕猎都会像这样结束 |
Less than 10% of her attacks are successful. |
出击的成功率不足10% |
But without her orange fur, |
但要是没有橙色皮毛 |
her chances would be even lower. |
它的机会还会更小 |
It is her colours that are key to her survival. |
颜色是它生存的关键 |
[wind whistling] |
|
The Cairngorm Mountains in Scotland. |
这里是苏格兰的凯恩戈姆山 |
Here, there are special problems for the hunted. |
在这里 捕猎也会遇到特别的难题 |
Some animals have developed camouflage of such perfection |
有些动物已经进化出了完美的伪装 |
that they are virtually invisible against their surroundings. |
几乎可以在周围环境中隐形 |
But what happens when those surroundings change? |
但是 如果环境改变了 那会发生什么呢? |
Well, then, of course, the animals have to change too. |
动物当然也必须随之改变 |
完整版请点击 |
|
These mountains are home to a particular kind of grouse |
这些山脉中 居住了一种特别的松鸡 |
called the ptarmigan. |
叫做雷鸟 |
[ptarmigan croaking] |
|
Their mottled brown feathers make them inconspicuous |
斑驳的棕色羽毛 让它们很容易藏身于 |
among the rocks and heather. |
岩石和石南属植物之间 |
But in winter, |
但是 到了冬天 |
these mountains are hard places in which to live. |
这些山脉就会变成很难生存的地方 |
Temperatures drop, |
温度下降 |
and the land can, overnight, be covered by a blanket of snow. |
一夜之间 大地就被白雪覆盖了 |
Most birds, by now, have gone south to warmer parts of the world, |
大多数鸟儿在这个时候 都已飞向南方更温暖的地方 |
but not the ptarmigan. |
但是雷鸟并没有这么做 |
When winter comes, |
冬天来临之时 |
they undergo the most extraordinary change. |
它们会发生特别巨大的变化 |
They replace their brown feathers with pure white ones. |
它们会换掉棕色羽毛 长出纯白色的羽毛 |
They do so for a simple reason. |
这么做的原因很简单 |
They must go unnoticed. |
因为它们必须不被发现 |
They need to hide. |
它们需要藏起来 |
[tense orchestral music playing] |
|
This open habitat |
这个开放的栖息地 |
makes the ptarmigan very vulnerable to predators. |
让雷鸟非常容易受到掠食者的攻击 |
Being the right colour is crucial. |
长对颜色很重要 |
Now they are invisible even to a keen-eyed eagle. |
现在即使是面对眼神敏锐的老鹰 它们也是隐形的 |
Ptarmigan are not the only animals to use this disappearing act. |
雷鸟不是唯一会采取 这种隐身行为的动物 |
So does the Arctic fox, |
北极狐 |
snowshoe hares, |
北美野兔 |
and weasels. |
黄鼠狼都是如此 |
All, with the coming of winter, |
冬天到来的时候 |
change their coats and vanish from sight. |
它们全都会改变外表 从视野中消失 |
Their transformation is triggered by the decreasing daylight, |
不断减少的日光 引发了它们的改变 |
and, over several weeks, |
经过数周的时间 |
they replace their brown costumes with white ones. |
它们的棕色外套就会变成白色 |
So changing colour with the seasons, |
因此 随着季节改变颜色 |
for some animals, |
对某些动物而言 |
is the only way to avoid becoming a meal. |
是避免成为捕食者食物的唯一方式 |
[wind whistling] |
|
But many plants, of course, |
但是 很多植物 |
do the reverse. |
恰好相反 |
[whimsical orchestral music playing] |
|
In spring, |
在春天 |
they produce colour to declare that they are providing food, |
它们会改变颜色 来表明自己可以提供食物 |
nectar. |
花蜜 |
Bees and many other insects love it. |
蜜蜂和许多其它昆虫 都很喜欢花蜜 |
In spring and summer, |
春夏季节 |
they travel busily from flower to flower collecting it. |
蜜蜂们穿梭在花丛间采蜜 |
And when the bees leave to look for more, |
当蜜蜂离开去寻找其他花蜜时 |
they inadvertently take pollen with them, |
会在不经意间进行授粉 |
which then fertilises the next flowers they visit. |
再接着给之后的花朵授粉 |
But there's a hunter here that exploits this relationship. |
但是这里还有一个猎人 想要利用这种关系 |
A crab spider. |
一只蟹蛛 |
She's tiny, no bigger than a fingernail, |
这只雌蛛很小 只有指甲盖大小 |
and she's waiting for her prey. |
它正在等待猎物 |
Almost the same colour as her background, |
它几乎和背景颜色一样 |
she's virtually invisible. |
几乎是隐身了 |
No more honey for her. |
这只蜜蜂再也采不到蜜了 |
But, of course, the spider's hunting grounds are limited. |
但是 蜘蛛的猎场当然也会受到限制 |
Not all flowers are yellow. |
并非所有的花都是黄色的 |