地平线系列：猫咪观察（1）（2014）

So why this vast difference?
那么为何会有这么大的差别呢
Well, cats' eyes have very few cones in them,
猫的眼睛里极少有视锥细胞
that's the colour receptive cells that we rely on to
那是人类的色彩感觉细胞
build up a colour picture of the world, the world that we see.
因此我们看这世界才会有彩色图像
On this picture of a cat's retina, you can see there's no central fovea
这是猫的视网膜图片 你看它就没有中♥央♥凹
which is the area that we have which is absolutely packed with cones.
而人类就有中♥央♥凹且布满了视锥细胞
In a cat's eye, there are far fewer of them
但在猫眼中 就极少有这些细胞
and those that there are, are spread out over the entire retina.
仅有的一些还是散布在整个视网膜上
What the retina is packed with is rods,
由于视网膜上多是视杆细胞
the black and white receptors that work much better in dim light
猫们在暗光下对黑白的感觉
than they do in bright light.
要比在亮光下强
And because in daylight rods are not very efficient,
因为视杆细胞在白天并不怎么有用
they tend to get a little bit washed out,
它们会有点儿疲倦
so it is a little bit more blurry and washed out than ours would be.
所以猫的视角就比人类的要模糊和泛白一点儿
And when we move into night-time or at least dusk,
而当天黑了或者暗了的时候
it gets even more interesting, doesn't it?
情况就更有趣了 是吧
Yeah, what happens at dusk is that,
是的 到了晚上之后
first of all, our eyes completely shut down,
首先人眼就废了
they pick up very little light.
吸收不了多少光线了
All we can really see is a bit of light in the sky
我们所能看到的就是天上的零星光线
and pretty much nothing else.
其它的就看不到了
Whereas in the cat vision,
而在猫的视觉中
you can see that the cat is still getting a really detailed picture
他们仍然能看到很清晰的画面
of what's going on on the ground,
看到地面上的各种东西
and that's essentially down to two things.
这基本上就靠两个原因
One is that a cat's eye has about five times as many rods in it
一是猫眼中的视杆细胞是人眼的
as ours does.
5倍之多
And they've got another feature which helps those rods to work
二是猫眼中闪亮闪亮的部分能帮助
even more efficiently which is the shiny bit behind the eye,
视杆细胞工作得更加高效
the tapetum, which we don't have
那是反光膜 人类是没有的
but if you shine a torch in a cat's eyes,
但如果你朝着猫眼打光的话
you can see literally that green eye shine coming back.
你就能看到它们的绿眼睛一闪一闪的
This reflective layer bounces the incoming light
这一反光层能把射入光
back through the cat's retina a second time,
二次反弹进视网膜
boosting its low light vision by up to 40%.
最多能帮猫提亮40%的低光图像
It's 10pm and village cat Sandwich is out on patrol.
夜间10点 乡下猫三明子外出巡逻中
Her eyes can see clearly in just one sixth of the light
她的眼睛只需要人眼所需光亮的1/6
that our eyes need,
就能看清
allowing her to spot the fox creeping past her garden.
所以她能看到狐狸穿过了她家花♥园♥
And to capture this moth.
甚至是看到这只飞蛾
She's seeing the world just as her wild ancestors would have done.
她观察这个世界的方式与其祖先一模一样
Our domestic cats are descended from pretty much nocturnal animals
家猫的祖先们多是些夜行族
that do most of their hunting at night or dusk and dawn.
其猎食多数都在夜间或黄昏或黎明中进行
So what we essentially have today is
所以基本上现在就是
an eye which works much better at night than during the day,
他们的眼睛在夜间要比在白天高效
even though our modern cats, our domestic cats don't really need that
虽然这对现在的猫 现在的家猫用处也不大
because we have electric light for them.
因为晚上也有了人类的电力光源
That's of no relevance to them,
但他们我行我素
they're still using a visual system that evolved millions of years ago.
依然用着那数百万年前演化出的视觉系统
Cats' eyes evolved to help them spot their prey in low light,
猫眼的进化帮助他们在弱光下发现猎物
whereas primates like us who sleep at night
而在夜间睡觉的我们这类灵长类动物
have eyes that evolved to work best in the day.
我们的眼睛则进化成最适合白天使用
Light levels have fallen enough now for my eyes to begin to struggle,
光亮度现在已经降得我眼睛快看不清了
but a cat's vision evolved to serve it well in this light
但猫眼进化得在此光亮下还能看得一清二楚
because dusk and dawn were peak hunting times
因为黄昏和黎明正是猫的祖先
for its wild ancestors.
的猎食高峰期
But while our cats have retained
不过既然猫咪们保留了
their ancestors' ways of seeing the world,
他们祖先观察这世界的方式
what about their behaviours?
那他们的行为是否也如此呢
Have their activity patterns changed with domestication?
被驯养后的他们有没有改变了行为习惯呢
We want to know if our cats are still most active at dawn and dusk.
我们想知道猫咪们是否在黄昏和黎明时仍最为活跃
We've fitted their GPS collars with motion sensors
我们给他们装的GPS上带有运动传感器
so we can tell if they're resting or out and about.
所以我们能知道他们是在歇息或是外出之类的
So, Harvey, we're beginning to get some data from our cats.
哈维 猫咪们给了我们一些数据
What do these plots tell us?
这些图形说明了什么呢
So what we're looking at here is plots from each of our three areas.
这些是我们三个研究区域的分♥析♥图表
The inner city cats on the left, our village cats in the middle
城里猫的在左 乡下猫的在中间
and the farm cats on the far right here.
农场猫的在最右边
And we're looking at the average activity from the cats
我们可以看到猫儿们的平均活动
and that's in black over the two days that we've tracked them for now.
黑色的轨迹就是我们两天来记录到的
We're seeing quite an obvious split between
我们可以看到城里猫和农场猫
our urban cats and our farm cats.
有着很明显的区别
You see the farm cats, they're much more active
农场猫他们较为活跃于
through the night and at dawn and dusk.
夜间 黎明 傍晚
Whereas with our urban cats they seem to be active
再看城里猫 他们似乎
throughout the whole day really.
整个白天都很活跃
The senses of our cats' wild ancestors
猫的野外祖先为了
were finely tuned for hunting at night
夜间捕猎而演化完善了其感官
and that's when our farm cats are most lively.
所以农场猫也是在夜间最为活跃
But with the same senses,
但有着同样感官的
why are our city cats so active during the day?
城里猫为何又会在白天那般活跃呢
All right, so, Alan, how can we unravel this?
好吧 那么艾伦 我们要怎么解释这个呢
I think our farm cats, they are hunting to eat,
我认为农场猫他们要捕猎进食
so they're going to go out and hunt when they're most successful.
所以他们会在成功性最大的时候外出猎食
Dawn and dusk is when the prey animals are active.
黎明和傍晚正是猎物最活跃的时候
They're hunting rats, they're hunting rabbits,
他们可以捕猎老鼠 捕猎兔子
so that's when they're going to be out and hunting.
所以他们会在那时候外出猎食
I think our domestic cats have been domesticated for many generations
我认为我们的家猫已经被驯化了多代
and quite a lot of their activity pattern probably relates
他们的许多行为模式可能都受到了
to what their owners are doing and when their owners are around.
主人们的生活的影响
The house may be warm in the evening cos the heating's on,
房♥里可能开着暖气 所以晚上也暖和着
the owner may be there and feeding them.
主人们可能也在给他们喂食
I think they're exploiting what resources are available to them.
他们利用着一切可用资源
And to be honest, the owners are one of the resources they'll exploit.
说实话 他们可以剥削他们的主人嘛
So despite being born with the same senses as the farm cats,
所以尽管长着和农场猫一样的感官
our urban cats may be adapting to fit in with us.
城里猫可能更适应了和人类生活
Is it dinnertime, Miss Piggy?
该吃饭了吧 皮吉小姐
It's the first hint we've had that the modern world our cats live in
时至今日 猫咪们所生活的这个现代世界
is clashing with thousands of years of evolution.
与其数千年来的进化产生了冲突
Our cats may see best in low light, but even in broad daylight,
猫咪们在低光中也许看得更清楚 但即使在大白天
they can spot things we barely notice.
他们也能注意到我们轻易忽略的事物
Three-year-old Bengal Kali is one of our village cats.
3岁的孟加拉猫 卡莉 是一只乡下猫
She spends hours chasing insects.
她追虫子追了几个小时
Sometimes they're out in the garden and you think,
有时看她们在花♥园♥里 你会想
"What are they chasing?"
她们究竟在追什么
They're hunting something but I normally can't see what it is.
她们追逐着什么 但我一般都看不清那是何物
Kali can detect even the tiniest fly,
卡莉甚至能看到最小只的苍蝇
moving so fast we can hardly see it.
它飞得太快以致我们都看不清
Flies, insects, anything that moves, really.
苍蝇啊 昆虫啊 只要在动的 她都要追
While our brains get swamped with
我们脑子里满是泛滥的
information about patterns and colour,
图像和色彩信息
through Kali's eyes, fast movement trumps everything.
而卡莉的眼里只有飞速运动的物体
As she stalks the flies,
她在追逐苍蝇时
her eyes send signals to the brain's visual cortex,
她的眼睛将信♥号♥♥传送至大脑的信♥号♥♥中枢
which analyses what's changed between one picture and the next
大脑对每幅画面间的差异进行分♥析♥
up to 70 times every second - faster than the human brain.
每秒刷新70次 比人脑快多了
And a far bigger proportion of the neurons
卡莉大脑里的神经元要比
than nerve cells in Kali's brain
神经细胞有着更多的
are dedicated purely to the detection of movement.
完全分属于运动侦测的部分
She almost can't help but pounce.
她几乎控制不住自己的扑追
The combination of low light vision
低光视力加上
and a remarkable ability to detect movement,
非凡的运动侦测能力
made it easy for the cat's wild ancestor to stalk the prey
使得猫的祖先更易追捕猎物
it relied on for survival.
以维持生存
But there's a downside to these evolutionary adaptations.
但这些进化而来的适应能力也有个缺点
Once the prey was close enough to catch, it went out of focus.
一旦猎物凑得太上来 猫眼就会失焦
In fact, cats can't focus on anything closer than about 30cm.
事实上 猫咪们无法看清30厘米之内的东西
But, of course, nature has taken care of that as well.
不过大自然自有其安排
Where their eyes fail them,
在目力不及的地方
cats rely on another perfectly adapted sense to go in for the kill.
猫咪们靠着演化出另一绝妙感官来终极一击