bbc講義貓眼看世界

1、Cats Uncovered1. Catsplayful pats, fearsome fightersdeadlyters. 2. They beguile us,rigue us, and mercilessly exploit us.9 But how much do we really understand these enigmatic creaturesK- we share our lives with?& Millions of us have cats in our homes.2 They re one of our favorite pets9 and yet we st

2、ill know very little about them.69 Yeah, hes a good boy. 9 & In last years Horizon, we revealed what the cats of one village & 2got up to once they left the cat flap.&-3 Now were taking it even further. Cats Uncovered9. In a ground-breaking scientific study, weve asked some of the worlds top cat exp

3、erts to run experiments&L 2investigating the secrets of our feline friends.2CH 10. To find out how our cats can unleash moreer9 Pn a racehorseWhappenshe milliseconds before your cat poun=9Q This is really extraordinarily detailed.& Id never expected to see all of this.77 and discover the secret weap

4、on behind their superb sense of balance.9 13. Tve even deepero their hidden world, &r9 were fitting our cats with se-of-the-art tracking deviand cameras.- &n 14. Were aiming to create the definitive guide to your cat.R 15. And one of the most fundamental questions we can ask is, how does the cat exp

5、erience the world?2PO 16. Tonight, well reveal how our pet cats see, smell5 Pand hear with the senses of a supreme predator.z 17.his series, wereng something unique. 18. Were following 100 catshree very different environments& 100 to get an insighto their secret lives.=9 19.he crowded terraof Hanove

6、r in central Brighton, were tracking city cats like Minky. 20. With so many cats crammedo so little space,) & her remarkable sense of smell has goneo overdrive and shes feeling stressed.z= #Cats Uncovered21. Just a fewaway,he leafy streets of Rottingdean, live our village cats. # 22. With space to r

7、oam,)m Kalis using her remarkable eyesight tot things we barely notice. 23. And were going to compare our urban moggies to a third group of cats. 24. Ive comeo the countryside where, for thetime, so we cso capture a cats-eye view of the world. & 56. And all this information, the GPS data, the spe- G

8、PS ilist footagethe rest of the info were accumulating about our cats,zx)- will be pored over by our team of technical experts and scientistssot we can build up the most comprehensiv= scture of the catweve ever had. s 公眾kaonor 諾誼獲取精品資源One of the biggest questions our scientists are asking is, how do

9、 cats experience the world around them? PO To help answer this, were going to see how their senses develop. & 9P 59. Tenks ago, we filmed rescue cat Smokey giving birth to= &a litter of kittens here at the Cats Protection centre. & out was white and black male Monty. 60.And weve been following him e

10、ver since.79& This kitten is the youngest member of our study. 63. And by following his development from day one,97 we can understand just how our cats experience the world.O all of fluff was a supreme predator.64. The wild antor to this cuittn 65. Andts key to finding out why, even though we share

11、the same home, PT &Cats Uncoveredcats smell, hear and see the world in a compley different way.9 2s 66. Today, Montys leaving the familiarity of the rescue center5 &and heading off to join our village cat population in Rottingdean.9r# There we go.& How is he?9 & At his new home theres a lot to take

12、in.9 & 70. For humans, viis our dominanse but what aboats?2 K!D o, little one. C 71.72. Montys eyes didnt open until he was around a &9k oldrevealing the bright blue irisest most cats are born with.9 1 73. By fourks, he could focus enough to see his mother 99&and detect depth well enough to walk wit

13、hout falliner.D 74. Well, almost.g!D 75. Now at tenks old, his blue eyes are changing to a golden green& 10 ,9&as deits of thgment melanin build upand his visual system is almosfull strength.9 & 76. But a cats-eye view of the world is very different to ours.K 77. Biologist Dr John Bradshaw has been

14、studying cats for over 25 years.& 25 78. Back at Cat HQ, hes helus to recreate cat vi. 9 79. Ok, so theres the comparison betn human and cat vi.& 2 80. What strikes me immediay about the cats field of view, colours are pretty much washed out and its all rather blurry. 3 Cats UncoveredSo why this vas

15、t difference? PD Well, cats eyes have few coneshem, ts the color receptive cells2t we rely on tobuild up a color picture of the world, the worldt we see. Di 83. On this picture of a cats retina, you can see theres no central foveawhich is the area Rt we have which is absoluy packed with cones.2 & 84

16、. In a cats eye, there are far fewer of themK -and thoset there are, are spread out over the entire retina.4 - 85. What the retina is packed with is rods,) the black and white receptorso t work much better in dim lightn theyn bright light.1o 86. And because in daylight rods are not very efficient, t

17、hey tend to get a littit washed out,Djd so it is a littit more blurry and washed outn ours would be.=2 j 87. And when we moveo night-time oreast dusk,&b it gets even moreeresting, doesnt it?& 88. Yeah, whappens at dusk ist,of all, our eyes compley shut down, & n2& they pick up very little light. &o&

18、 89. All we can really see is a bit of lighthe sky and pretty much nothing else. oz & 90. Whereashe cat vi, you can seet the cat is still getting a really detailed picture96of whats going on on the ground, andts essentially down to two things. (Cats Uncovered91. One ist a cats eye has about five tim

19、es as many rods in it as ours does. 2 5 92. And theyve got another feature which helps those rods to work( 11even more efficiently which is the shiny bit behind the eye,Q the ttum, which we donve but if you shine a torch in a cats eyes,o 2KRo you can see literallyt green eye shine coming back.R 93.

20、This reflective layer boun orotheing lightback through the cats retina a second time,( boosting its low light viby up to 40%.1 40%Moi Its 10pm and village cat Sandwich is out on patrol. 10 # Her eyes can see clearly in just one sixth of the lightt our eyes need,2o1 1/6 allowing her to spot the fox c

21、reng past her garden.=& And to capture this moth. Shes seeing the world just as her wild antors would have done. zn 98. Our domestic cats are descended from pretty much nocturnal animalsn-t do most of theirting at night or dusk and dawn.z 99. So whatssentially have today is= an eye which works much

22、better at night9 n during the day,even though our modern cats, our domestic cats dont really need ! because we have electric light for them. !&2o t100.ts of no relevance to them,K9theyre still using a visual systemt evolved millions of years ago.W )Cats Uncovered101. Cats eyes evolved to help them s

23、pot their prey in low light,9o whereas primates like us who sleep at nighthave eyest evolved to work besthe day.T 102. Light levels have fallen enough now for my eyes to bego1 & o struggle,but a cats vievolved to serve it wellhis lightKo1 (because dusk and dawn were peakting times for its wild antor

24、s. n103. But while our cats have retained their an tors ways of seeing the world, &9n what about their behaviours?9 ! 104. Have their activity patterns changed wit domestication?9& We want to know if our cats are still most active at dawn and dusk.6 Weve fitted their GPS collars with motion sensors9

25、 GPS Eso we can=l if theyre resting or out and about.9 107. So, Harvey, were beginning to get some data from our cats. &108. What do these plots - l us?-&3 109. So what were looking at here is plots from each of our three areas.- 110. The inner city cats on the left, our village cats # and the farm

26、cats on the far right here. he middle111. And were looking at the average activity from the cats=jandts in black over the two dayst weve tracked them for now. 112. Were seeing quite an obvious spilt bet=our urban cats and our farm cats n*Cats Uncovered113. you see the farm cats, theyre mu9 )ore acti

27、vethrough the night and at dawn and dusk.h 114. Whereas with our urban cats they seem to be active9J throughout the whole day really. 115. The senses of our cats wild antors were finely tuned forting at nightn &zandts when our farm cats are most lively.=! 116. But with the same senses,K why are our

28、city cats so active during the day? PD 117., so, Alan, how can we unravel this? F 118. I think our farm cats, they areting to ear, 9 so theyre going to go out andt when theyre most sucsful.=9Db 119. Dawn and dusk is when the prey animals are active.hb 120. Theyreting rats, theyreting rabbits,9= q so

29、ts when theyre going to be out andting.=9Db 121. I think our domestic cats have been domesticated for many generations &;and quite a lot of their activity pattern probably relates9 &to what their owners areng and when their owners are around. 2 122. The house may be warmhe evening cos the heatings o

30、n,= !the owner may be there and feeding them. 2!9 123. I think theyre exploiting what resour9 are available to them.124. And to be honest, the owners are one of the resour 9=9 2 theyll exploit.+Cats UncoveredSo despite being born with the same senses as the farm cats,= our urban cats may be adapting

31、 to fit in with us.&2 Is it dinnertime, Miss Piggy?& 127. Its thehweve hadt the modern world our cats live in5 ; is clashing with thousands of years of evolution. z/& 128. Our cats may see best in low light, but even in broad daylight,Mo ! KT they can spot things we barely notice.9! Three-year-old B

32、engal Kali is one of our village cats.3 # She spends hours chasing insects.& 131. Sometimes theyre outhe garden and you think, “What are they chasing?”RD “3 ”132. Theyreting something but I normally cant see what it is.3 K P 133. Kali can detect even the tiniest fly, moving so fast we can hardly see

33、 it. = 134. Fs, insects, anythingt moves, really. 135. While our brains get swed with information about patterns and colour,ithrough Kalis eyes, fast movement trumps everything.O 136. As she stalks the fs, her eyes send signals to the brains visual cortex,which E yses whats changed betn oncture and

34、the nextup to 70 times every second-faster 70 2& n the human brain.137. And a far biggroportion of the neuronsn nerve cells in Kalis brainkare dedicated purely to the detection of movement.s)X 138. She almost cant help but pounce. N Cats Uncovered139. The combination of low light viMo and a remarkab

35、le ability to detect movement,X made it easy for the cats wild antor to stalk the prey it red on for survival.Tn= But theres a downside to these evolutionary adapions.K-! Once the prey was close enough to catch, it went out of focus. D 142. In facts, cats cant focus on anything closern about 30cm. 3

36、0 But , of course, nature has taken care oft as well. z Where their eyes fail them, cats rely on anoth公眾kaonor 諾誼獲取精品資源erfectly adapted sense to go in for the kill. 145. Weve set up an experiment to reveal just how our cats secret weapon works.& 146. The cmera cann full HD resolution up to 2,700 fra

37、mes a second. 2700 s 147. I would have thought 20 to 30 times will get it. 2030 & 148. John Bradshaw is hothese ultra high speed cameras-will capture this extraordinary sensoryan in action. 149. It really is very, very quick. 150. Ive seen still photographs of ippening, but theres nothing like actua

38、lly seeing the whole motion.K ) 151. So I think we got it there.= But it is very, very quick.K & Johns trying to observe the cats whiskersQas they move forwardo the attackition.c9 #Cats UncoveredLets just take the toy away for a second and letsn DjCan we have a look at what weve just taken? Ok, so h

39、ere we go. The cat realizes the mouse is within his grasp 9&but he wants to know exactly where it is in relation to his mouth.K9 Its eyes give up because they cant focus very close. & 159.ts where the whiskers take over.) & 160. So what we can see here is the whiskerddenly being st forward. And now

40、the claws are coming So what weve got here, look,= o action.the whiskers are poing almost directly in front of the cats nose. 7I 163. In fact, hes catching them with his claws 9as he sps round trying to catch the mouse.!I& 164. But the little muscles at the base of each whiskerKare really tugging ha

41、rd to swing those forwardzcompley out of the normals& ition.This is really extraordinarily detailed. Id never expected to see all of this. $Cats Uncovered167. It all seems to take place in about a fifth of a second J 1/15 which just shows how fast cats reflexes really are,& from the powhere they sp

42、the whiskers forward9where the muscles contract and then relax backand the whiskers spring back again. 168. The mouse doesnve a chance.& 169. Far thicker and longern normal hairs,& whiskers also sit three times deeper 3 ) where they attach to nerve endingshe skin獲取ling the cat how far each is being

43、bent back and how quickly.& 170. Their whiskers are the same wids the cats body,9O so they can navigate the narrowest spa=9 .171. Cats also have whiskers above their eyes and on their ! sending them a constant stream of information= 9Vas they sense the world around them.9 les,172. The evolution of s

44、uperb low light viand hyper sensitive whiskersMowere critical for the cats role as a supreme predator. ting arsenal, it would never have survived.173. But ifts all the cad in itsK 9 & 174. Mice and other rodents, the cats main prey, are mostly hidden from view, so another sense was just as crul- hea

45、ring.= ! 175. Cats are almost compley deaf at birth. %Cats Uncovered176. So as a newborn,) all our kitten Monty could hear was a dull buzz around him. 177. But by ak old, he was responding to specific sounds 9-Q&and by fourks he could orient himself4 9towards the direction a sound was coming from.P&

46、 獲取資源178. But back in Brighton, our urban moggies arent always using itheir hearing in quite the way their wild antors would have done.zT& 179. Tia! Dinnertime. Coco! Eric! Mikey., p 180. Cat behavior expert Dr Sarais has been studying just how our cats hear the world. P 181. Sarah, clearly cats are

47、elligent enough to assote certain sounds with the arrival of food- but how good are they at hearing? K9 182. Well, really good. 183. One of the thingst makes them so good at hearing different sounds9 is these huge earst they have.9 These structures are called pinnae and they can use those as-9Qto re

48、ally boost sound. But also they use them to help locate where the sound is.9L Our ears are pretty fixed on the side of our head here, but their ears can roe independently of one another.K9* And those movements can be up to 180 degrees. 180 lifiers&Cats UncoveredYeah, I mean, its pretty extraordinary

49、, isnt it?, &,?Theyre constantly listening out for9 sounds behind them, before them, above them, below them. 190. The ability to roe their ears is just thein detecting where sound is coming from.X stageOne of the ways is how quickly the sound comes to each ear. So therell be a time delayA tiny time

50、delay, though.DK Yep, very, very small,but they have a huge number of neuronsK9k7t go from the earto the brao deciphert information, moren we do as humans., 2 195. The time delayls the cat&whether a sound is to the left or right of them.9 196. And corrugations inside the ear distort the sound depend

51、ing on whether its coming from above or belowDallowing cats to pinpoa sounds precise location in just a fraction of a second.L4 197. Our cats ears also far surpass our ownhe range of soundsthey can hear, about 11octaves9w 11 t!)2otal,a wider rangen almost any other mammal. zP& 198. They can hear, if

52、 we think about low frequencies,9,M,as the same range as us, if you like.199. But if2 xtend up towards the high frequencies,K,they can hear actually approximay two octaves highern us.9 2 t Cats Uncovered200. Andt range is what we could call ultrasound.& 201. Andts great because theyve adapted really

53、 well9to the soundszDt their prey makes, so small rodentch as mice, the sounds they make will behat ultrasound range. 202. This gives our cats acs to a whole world of sound ts compley inaudible to us.s 203. To see this in action, weve used spelist equipment ,&- to transmit ultrasonic calls from mice

54、, rats and bats inside the houses of some of the cats in our study. The sounds are all above 22 kilohertz-s 22 = which should be well outside the range of a human ear.!2 Their owners are oblivious. 2 No, I cannot hear any animal noises. P Yeah cant hear a thing , nothing at all, not a sausage.3 But

55、once we let the cats in, its a different story.K & It takes lessn a minute for them to locate the source of the sounds. 9L& 209. Its only by lowering the frequencyt we can enter the cats worldMand hear this mouse almost as they do. 9& 210. Our cats well-honed senses evolved to equip their wild antor

56、Tznwith the tools they needed to& t.211. We only started treating them as pets around 100 years ago. 100 9 212. In evolutionary terms,ts the blink of an eye and theyve hardly changed. 9! (Cats Uncovered213. So whappens when the sensest evolved for survivalhe wild= collide with the domesticated cats

57、world? D 214. Three-year-old Daisy is one of our village cats3 # and like 80% of the cats in our study, she has a cat flap to get outside. 80% V 215. But Daisy refuses to use hers.K 216. Trapped inside, she rarely ventures out !unless she can persuade a human to help. 2 & 217. Do you want to go out?

58、R 218. Do you wantR pen the door?Come on, then. Go on, then.& Off you go. We have a cat flapt, you know,& Daisy can come in and out of as she so desires,but shed much rather use the doorK Tand we think this is because shes terribly, terribly&hand just refuses to do work2 t humans can do for her.222.

59、 So shed much rather stand and wait for the door to be opened=j2n actually push. 223. She is the prins cat.u 224. She is the prins cat.u 225. Tooh to push. 226. And shesngt now.j& )Cats Uncovered227. Vet Rachel Casey tackles problem cat behavior on a daily basis: and she beves Daisys reluctance is c

60、aused by something far more fundamental 228. Experienced through the senses of her wild annE n sheer laziness.tors,this simpl ece of plastic can be terrifying. Cat flaps are very different things for people and for cats.)2 Now you go off to the pet store and you buy somethingR&$&-which says cat door