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Did you know,
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dolphins can look inside our bodies?
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Snakes have thermal imaging.
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Ants can predict earthquakes
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and platypus can sense electrical pulses, like a shark can.
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We enjoy the rich colors,
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sounds and smells of the natural world,
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but it seems there is a lot we miss out on.
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(playful music)
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The five senses, sight, smell, hearing,
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taste and touch have been taken to extremes
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across the animal kingdom.
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And some have powers we can only dream of.
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To accommodate these superpowers,
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animals have some of the weirdest features
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and quirks of behavior,
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revealing to them the world we miss.
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(playful, magical music)
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(wind blowing)
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We live on an incredible planet.
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(waves crashing)
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(gentle music)
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The endless colors,
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(gentle music)
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smells,
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(chainsaw buzzing)
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sounds,
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(African drumming)
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and textures of nature.
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We lap them up with our key senses.
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(light music)
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These basic senses are common in the animal kingdom.
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(light music)
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Some senses, like vision, we are pretty fortunate with
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and can hold our own among most animals.
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(monkey squawks)
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(light music)
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With others, like our sense of smell,
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the animals leave us in the dust.
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But we can only perceive what we can perceive.
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(light music)
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There is a world beyond our senses we can scarcely imagine.
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(light music)
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We all know our sense of smell
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is limited compared to animals,
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especially our canine companions.
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(suspenseful music)
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Some dogs, like bloodhounds, can pick up scent trails
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two weeks after they were laid
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and follow them for a hundred kilometers or more.
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(dog barks)
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But their skills are not unique.
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Brown bears have a better sense of smell than a bloodhound.
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They're said to be able to detect food
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from 30 kilometers away.
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(playful music)
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And polar bears can sniff out seals
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that are under thick ice.
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(playful music)
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The sensory area to pick up and decipher smells
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is 100 times bigger in a bear than it is in us.
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(playful music)
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Oh, I think polar bear is coming.
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(playful music)
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Many very diverse animals
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have this extraordinary gift.
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(light music)
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Birds are visual creatures without a strong sense of smell.
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But the turkey vulture breaks the mold.
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The olfactory part of its brain is four times bigger
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than even close cousin, the black vulture.
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Soaring on thermals, they pick up the tiniest whiff
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and can find food a kilometer and a half away.
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The silk moth family are even more impressive.
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Though not using their noses,
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when they are ready to breed,
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female moths waft pheromones, insect perfume to lure males.
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The males have much larger antenna than the females.
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They look like feathers, but they are scent catchers.
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It only takes one molecule of scent to alert the boys.
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They can pick up the traces of a potential mate
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from more than 11 kilometers away.
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(light music)
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(ominous music)
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Sharks could be called the bloodhounds of the sea.
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It's thought a shark can pick out
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a single drop of blood in 10 billion drops of water.
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And can locate food from hundreds of meters away.
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(ominous music)
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But according to science,
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the best sniffer is something different.
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Scientists analyzed the genes in a wide variety of animals
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and found elephants came out on top
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with 2000 genes devoted to their sense of smell.
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This is twice as many as a bloodhound
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and five times more than us.
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They can detect and follow the scent of water
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from 20 kilometers away,
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a life saving skill on the baking plains.
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With such incredible abilities,
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it's hardly surprising they have the biggest
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and weirdest noses going.
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(playful music)
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(elephant honks)
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(playful music)
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The colossal pachyderm proboscis
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does a lot more than detect smells.
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(playful music)
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It can lift many liters of water.
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(exciting, playful music)
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Pick up tiny blades of grass.
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(exciting, playful music)
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Or tear down trees.
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(exciting, playful music)
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It's a tool like a fifth leg and hand all in one.
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(exciting, playful music)
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On top of that, it's a trumpet.
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(elephant trumpets)
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These many uses are thanks to some 40,000 muscles
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that powerfully control every move.
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(playful music)
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And of course, it's a tool for breathing.
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(cow moos)
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Strangely, after studying the number
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of scent-related genes in different species,
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Scientists concluded that cows and mice
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both have many more genes
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devoted to smelling than bloodhounds.
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With this way of measuring,
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elephants came first, followed by rats.
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(playful music)
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The sense of smell in those rodents is so well developed
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that they can even be trained to sniff out cancer
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and help to locate undetonated landmines.
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(playful music)
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Rats have another peculiarity among mammals,
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they have binocular sniffing.
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(rats chittering)
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An incredible skill, so far,
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only recognized in them and moles.
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They can detect which nostril receives the stronger scent,
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helping them to more accurately follow the trail.
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(playful music)
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Noses are one of the most prominent features of the face.
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(playful music)
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And their variety is weird,
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(suspenseful, playful music)
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and wonderful.
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(playful music)
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There are some seriously strange noses out there.
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Like the proboscis monkeys of Borneo.
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(monkeys chattering)
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The males have hand-sized honkers
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to help amplify their calls.
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(monkeys chattering)
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Tapirs have mini trunks to detect danger.
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(playful music)
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And help them pull high-growing leaves into their mouth.
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(sniffing)
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(playful music)
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For many animals, nostrils can help filter out dust.
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And in a few antelope, the function has been enhanced.
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Both saiga And dik-dik have big ones.
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The large air chambers help to control
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the temperature of the air they breathe.
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It's air conditioning.
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(light music)
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Even more advanced in camels, who use their large noses
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to absorb moisture from the air before they breathe it out,
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conserving every tiny drop.
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Pigs are famous for their sensitive snouts too.
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(playful music)
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And their noses are unique,
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(playful music)
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with a tough cartilage disc at the end that they can angle.
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(playful music)
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It is a built-in shovel for rummaging and digging for food.
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This, combined with their acute sense of smell,
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is what them such renowned trufflers.
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(playful music)
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The key to this skill
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isn't just their sense of smell, but sex.
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Truffles contain a sexy hormone
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that male pigs secrete in their saliva
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and that the girls find hard to resist.
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So if you want to uncover a truffle,
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get yourself a female pig.
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Though, be careful to grab it,
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before she makes a pig of herself.
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(water trickling)
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(men speaking foreign language)
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Our noses are nothing to be sniffed at
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but other animals could rightly look
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down their noses on ours.
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But as you'll see, our vision is an eyeopener.
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(light music)
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Most primates have average eyesight.
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But ours is exceptional.
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We have three types of color-detecting cones in our eyes,
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giving us a broader spectrum of colors
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than most other mammals.
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(water trickling)
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We are not leaders in the field.
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Some kinds of shrimp have 15 kinds of cones,
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rather putting ours to shame.
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But our vision is better than most.
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(water splashes)
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Most mammals use their eyes
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as part of their arsenal of senses.
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(water splashing)
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Only a few, like bats, river dolphins and moles,
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creatures who live in dark conditions
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have tiny eyes and poor vision.
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(light music)
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Most mammals see a bit of color
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but usually have fewer cones than us,
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so don't see as many colors.
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(light music)
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It's thought that mammal ancestors were mostly nocturnal,
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perhaps so they could hide from dinosaurs in the early days.
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Mammal eyes have sacrificed sharpness and color
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that are typical of day-active birds and reptiles
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in favor of eyes that are light sensitive.
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Humans are the exception.
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(playful music)
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We are more dependent on vision than any other mammal
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and have better color perception than most.
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(playful music)
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Our vision isn't perfect.
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We have 200,000 receptors
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for every square millimeter of our eyes,
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which gives us the sharpness and clarity of our vision.
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Buzzards have 1 million,
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so we can only imagine the incredible detail they perceive.
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(bird squawks)
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(light music)
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But even with our quite good vision,
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we are only perceiving a tiny part of the light spectrum.
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There are lots of colors we can't see
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and a weird and wonderful array of animals that can.
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Ultraviolet is the part of light that we try to block out
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with our sunglasses and sun cream to protect our skin.
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The lenses in our eyes naturally block it out.
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We can't see it, but many other species can.
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In fact, science keeps revealing a growing list of animals
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that can perceive ultraviolet, including bats,
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a range of marsupials, hedgehogs, even cats and dogs.
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(suspenseful music)
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Whether most see and use
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this part of the color spectrum is unknown,
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but there are many species that actively do.
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(playful, suspenseful music)
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Rodents for example, like rats and mice,
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can see each other's urine, glowing ultraviolet,
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helping them to find each other.
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(playful music)
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And birds of prey like kestrels,
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can also see mice urine to help them locate their dinner.
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(suspenseful music)
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(bird squawking)
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We love the color of flowers,
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their dazzling array of hues.
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But we can only see the spectrum from red to violet.
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Many flowers absorb or reflect ultraviolet light
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to create dramatic patterns that are invisible to us.
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And it's possible they use these specifically
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to attract animal eyes sensitive to the colors,
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such as bees.
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(gentle fluttering)
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Hummingbirds too, are sensitive to these floral flags.
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(gentle fluttering)
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00:19:17,970 --> 00:19:22,970
But the winners are butterflies.
273
00:19:23,117 --> 00:19:26,270
(playful, upbeat music)
274
00:19:26,270 --> 00:19:28,310
They are believed to see a wider range
275
00:19:28,310 --> 00:19:30,970
of colors than any other species,
276
00:19:30,970 --> 00:19:33,563
with 15 different types of receptors.
277
00:19:34,514 --> 00:19:37,940
(playful music)
278
00:19:37,940 --> 00:19:40,900
They use eye-like markings on their wings
279
00:19:40,900 --> 00:19:44,313
to look like predators faces to scare off attackers.
280
00:19:45,726 --> 00:19:48,476
(playful music)
281
00:19:51,226 --> 00:19:55,976
And they use color to attract and assess potential mates.
282
00:19:56,830 --> 00:19:59,930
The vibrancy of the colors helping them to identify
283
00:19:59,930 --> 00:20:02,010
the healthiest possible partner.
284
00:20:03,822 --> 00:20:05,989
(buzzing)
285
00:20:08,487 --> 00:20:11,070
(wind blowing)
286
00:20:12,190 --> 00:20:16,963
Unlike our lenses that block UV, most mammals' don't.
287
00:20:18,300 --> 00:20:21,193
So they see a little more of the spectrum than we do.
288
00:20:23,110 --> 00:20:26,303
But to be especially sensitive to it is unusual.
289
00:20:28,690 --> 00:20:32,200
Researchers were recently surprised to discover
290
00:20:32,200 --> 00:20:35,540
that many marsupials and monotremes, like platypus
291
00:20:38,440 --> 00:20:41,533
and echidnas glow under UV.
292
00:20:46,316 --> 00:20:48,150
No one is sure why,
293
00:20:48,150 --> 00:20:51,403
but it might be an aid to their nocturnal lifestyles,
294
00:20:52,850 --> 00:20:55,083
helping them find each other in the dark.
295
00:20:56,637 --> 00:20:58,887
(crickets)
296
00:21:00,900 --> 00:21:04,530
Amazingly, reindeer can adapt their color-viewing
297
00:21:04,530 --> 00:21:05,993
to match the seasons.
298
00:21:07,568 --> 00:21:10,568
(reindeer grunting)
299
00:21:11,870 --> 00:21:14,383
They shift their vision towards ultraviolet.
300
00:21:16,730 --> 00:21:20,120
During the long dark months of the arctic winter,
301
00:21:20,120 --> 00:21:22,320
the deer can use the extra light rays
302
00:21:22,320 --> 00:21:24,580
to help them locate lichens,
303
00:21:24,580 --> 00:21:26,833
which faintly reflect the UV light.
304
00:21:30,400 --> 00:21:33,943
And both the urine and the bodies of polar bears
305
00:21:33,943 --> 00:21:36,210
and wolves might stand out more against the snow
306
00:21:36,210 --> 00:21:40,013
to the reindeer's sensitive eyes, helping to keep them safe.
307
00:21:41,713 --> 00:21:44,296
(wind howling)
308
00:21:50,700 --> 00:21:53,093
Many animals depend on night vision.
309
00:21:54,870 --> 00:21:58,270
And rather than color-sensing cones we have favored,
310
00:21:58,270 --> 00:22:02,800
they have more rods, enhancing any trace of light.
311
00:22:02,800 --> 00:22:05,690
(playful music)
312
00:22:05,690 --> 00:22:07,290
The most skilled specialists
313
00:22:07,290 --> 00:22:09,243
have inspired road safety design.
314
00:22:11,520 --> 00:22:14,930
So-called cats eyes in the road are bits of glass
315
00:22:14,930 --> 00:22:18,453
that reflect back light in the same way cat's eyes do.
316
00:22:19,357 --> 00:22:22,024
(playful music)
317
00:22:23,682 --> 00:22:26,432
(car horn beeps)
318
00:22:27,570 --> 00:22:30,283
Many species have eyes that glow in torchlight.
319
00:22:33,467 --> 00:22:35,560
Known as eye shine,
320
00:22:35,560 --> 00:22:38,900
the glow is because most nocturnal animals
321
00:22:38,900 --> 00:22:42,450
have a shiny layer in the back of their eyes
322
00:22:42,450 --> 00:22:47,450
called the tapetum lucidum, which is like a mini mirror.
323
00:22:47,850 --> 00:22:49,653
It reflects light back.
324
00:22:51,720 --> 00:22:55,343
The retina is the part of the eye that sees the world.
325
00:22:56,219 --> 00:22:59,600
(serene music)
326
00:22:59,600 --> 00:23:01,760
The dim light enters the eye
327
00:23:01,760 --> 00:23:03,973
and passes through the retina in us.
328
00:23:05,560 --> 00:23:08,550
But in nocturnal animals, it is reflected
329
00:23:08,550 --> 00:23:10,003
and passes through again,
330
00:23:11,280 --> 00:23:14,371
increasing the light the eye has to work with.
331
00:23:14,371 --> 00:23:17,450
(serene music)
332
00:23:17,450 --> 00:23:21,617
The enhanced image is like our night vision technology.
333
00:23:21,617 --> 00:23:24,200
(serene music)
334
00:23:29,430 --> 00:23:31,680
We and the rest of mammal kind
335
00:23:31,680 --> 00:23:35,633
are also restricted by the number of eyes, a pair a piece.
336
00:23:37,890 --> 00:23:41,023
Spiders famously have eight eyes.
337
00:23:42,600 --> 00:23:45,270
Their vision isn't as good as ours,
338
00:23:45,270 --> 00:23:47,090
but they have broken down the tasks
339
00:23:47,090 --> 00:23:48,593
between the different pairs.
340
00:23:50,980 --> 00:23:53,750
In jumping spiders, it's the big pair
341
00:23:53,750 --> 00:23:55,683
at the front that sees best.
342
00:23:57,970 --> 00:23:59,993
They capture the most detail,
343
00:24:01,500 --> 00:24:03,045
but the other three pairs
344
00:24:03,045 --> 00:24:04,573
are more sensitive to movement,
345
00:24:06,240 --> 00:24:09,178
spotting predators or prey.
346
00:24:09,178 --> 00:24:11,928
(playful music)
347
00:24:17,210 --> 00:24:20,373
And giving the odd-eyed hopper's amazing depth perception.
348
00:24:21,251 --> 00:24:24,001
(playful music)
349
00:24:35,770 --> 00:24:39,603
Scallops and clams are on the ball, eye-wise.
350
00:24:42,060 --> 00:24:44,530
They can have hundreds of tiny eyes
351
00:24:44,530 --> 00:24:47,420
spread along the gap between shells.
352
00:24:47,420 --> 00:24:49,210
Their vision is poor.
353
00:24:49,210 --> 00:24:52,403
They do see some color, but not much detail.
354
00:24:54,620 --> 00:24:57,350
But there are so many eyes that they can pick up
355
00:24:57,350 --> 00:24:59,810
the movement of approaching predators,
356
00:24:59,810 --> 00:25:01,803
just in time to clam up.
357
00:25:04,420 --> 00:25:07,087
(playful music)
358
00:25:11,040 --> 00:25:15,930
And dragonflies have 360 degree vision.
359
00:25:15,930 --> 00:25:18,560
Thanks, not to one pair of lenses,
360
00:25:18,560 --> 00:25:21,463
but 28,000 pairs of lenses.
361
00:25:24,300 --> 00:25:27,130
Eagle eyes enable their lightning-fast reactions
362
00:25:27,130 --> 00:25:29,023
and spectacular coordination.
363
00:25:30,838 --> 00:25:33,588
(playful music)
364
00:25:44,720 --> 00:25:47,663
And a few more oddballs among eyeballs.
365
00:25:51,335 --> 00:25:54,491
(ominous music)
366
00:25:54,491 --> 00:25:57,743
Ostrich's eyes are bigger than their brains.
367
00:26:00,350 --> 00:26:03,813
They have the biggest eyes of any living land creature.
368
00:26:06,476 --> 00:26:09,476
(suspenseful music)
369
00:26:10,630 --> 00:26:14,320
Their perceptive peepers, combined with their height,
370
00:26:14,320 --> 00:26:16,903
make them expert at spotting approaching danger.
371
00:26:20,820 --> 00:26:24,360
And for that reason, antelope and other animals
372
00:26:24,360 --> 00:26:27,123
like hanging out near the bird-brained watch towers.
373
00:26:28,819 --> 00:26:31,486
(ominous music)
374
00:26:52,300 --> 00:26:55,090
Perhaps the weirdest eyes you could imagine
375
00:26:55,090 --> 00:26:57,560
belong to the chameleon.
376
00:26:57,560 --> 00:27:00,310
(playful music)
377
00:27:04,050 --> 00:27:08,344
Little pin pricks on the end of highly mobile stalks.
378
00:27:08,344 --> 00:27:11,344
(suspenseful music)
379
00:27:14,870 --> 00:27:17,493
They can move each eye independently,
380
00:27:18,650 --> 00:27:21,503
enough to make you go cross-eyed just thinking about it.
381
00:27:23,512 --> 00:27:26,512
(suspenseful music)
382
00:27:27,690 --> 00:27:32,040
Amazingly, they can enjoy monocular vision from each eye
383
00:27:32,040 --> 00:27:34,600
scanning the environment all around them
384
00:27:34,600 --> 00:27:37,063
and interpreting each view separately.
385
00:27:40,990 --> 00:27:43,233
But then when they spot prey,
386
00:27:45,370 --> 00:27:49,480
both eyes swing forwards giving binocular vision,
387
00:27:49,480 --> 00:27:51,713
the perfect depth perception.
388
00:27:52,574 --> 00:27:55,241
(gentle music)
389
00:28:11,090 --> 00:28:13,063
We enjoy the visuals of the world,
390
00:28:14,473 --> 00:28:17,056
(gentle music)
391
00:28:21,400 --> 00:28:24,993
but life's rich soundtrack can be just as exciting.
392
00:28:26,530 --> 00:28:29,363
(thunder crashes)
393
00:28:32,934 --> 00:28:35,851
(orchestral music)
394
00:28:41,750 --> 00:28:45,253
Listening to an orchestra, the air is alive with sound.
395
00:28:46,843 --> 00:28:49,760
(orchestral music)
396
00:28:50,600 --> 00:28:53,050
A rich cascade of notes,
397
00:28:53,050 --> 00:28:56,333
but we can only hear a fraction of the world's sounds.
398
00:28:57,467 --> 00:29:00,217
(exciting music)
399
00:29:01,450 --> 00:29:05,820
Many sounds are above or below our hearing range.
400
00:29:05,820 --> 00:29:09,588
And our range gets narrower as we get older.
401
00:29:09,588 --> 00:29:12,505
(orchestral music)
402
00:29:17,600 --> 00:29:19,720
Some animals not only hear,
403
00:29:19,720 --> 00:29:21,986
but harness sound in ways
404
00:29:21,986 --> 00:29:24,294
that seem fit only for superheroes.
405
00:29:24,294 --> 00:29:26,877
(light music)
406
00:29:27,850 --> 00:29:31,440
We know ultrasound, the very high pitched sound waves
407
00:29:31,440 --> 00:29:34,413
we can fire into our bodies to look inside them.
408
00:29:36,330 --> 00:29:38,153
It seems like space-age technology,
409
00:29:39,950 --> 00:29:43,757
But animals harnessed this power millions of years ago.
410
00:29:45,887 --> 00:29:48,640
(church bell tolls)
411
00:29:48,640 --> 00:29:50,683
Bats are creatures of the night.
412
00:29:52,900 --> 00:29:55,490
Their eyes are tiny and weak.
413
00:29:55,490 --> 00:29:58,523
There's no point investing in eyes for a life in the dark.
414
00:30:02,660 --> 00:30:05,423
Their world is one of acoustics.
415
00:30:06,271 --> 00:30:09,790
(church bell tolls)
416
00:30:09,790 --> 00:30:12,850
Most of the sounds bats make are too high pitched
417
00:30:12,850 --> 00:30:14,393
for our ears to pick up.
418
00:30:15,390 --> 00:30:17,960
It's only when the sounds are slowed down
419
00:30:17,960 --> 00:30:21,000
that they reach a frequency we can hear,
420
00:30:21,000 --> 00:30:23,758
allowing us to listen in on their world.
421
00:30:23,758 --> 00:30:27,175
(high-pitched squeaking)
422
00:30:33,980 --> 00:30:37,750
As the bats fly, they make their high-pitched squeaks
423
00:30:37,750 --> 00:30:39,730
and their huge sensitive ears
424
00:30:39,730 --> 00:30:42,233
listen for the returning echoes of their calls.
425
00:30:46,260 --> 00:30:48,390
This helps them map out the landscape
426
00:30:48,390 --> 00:30:50,383
and navigate through obstacles.
427
00:30:52,975 --> 00:30:56,392
(high-pitched squeaking)
428
00:31:04,550 --> 00:31:08,440
And when the sound hits other animals, (thunder crashes)
429
00:31:08,440 --> 00:31:13,083
like flying insects, it can help them to target their prey.
430
00:31:16,220 --> 00:31:18,940
Incredibly some insects have learned
431
00:31:18,940 --> 00:31:20,613
to use their weapon against them.
432
00:31:22,100 --> 00:31:24,890
(light music)
433
00:31:24,890 --> 00:31:26,960
Some crickets emit frequencies
434
00:31:26,960 --> 00:31:29,083
that cancel out the bat sounds.
435
00:31:30,728 --> 00:31:33,311
(light music)
436
00:31:34,490 --> 00:31:36,510
And the wings of moths are stacked
437
00:31:36,510 --> 00:31:39,770
with little scales that can absorb sounds,
438
00:31:39,770 --> 00:31:40,820
softening the echoes.
439
00:31:41,915 --> 00:31:44,498
(light music)
440
00:31:54,980 --> 00:31:57,823
Dolphins, deploy a very similar tactic.
441
00:32:00,280 --> 00:32:03,800
In their murky, churning, underwater world,
442
00:32:03,800 --> 00:32:05,883
vision is not very reliable.
443
00:32:08,290 --> 00:32:11,420
They produce high pitch clicks and whistles,
444
00:32:11,420 --> 00:32:14,079
and again harvest the echoes.
445
00:32:14,079 --> 00:32:17,079
(dolphins clicking)
446
00:32:19,430 --> 00:32:23,047
They can make out the sea bed and scan for prey.
447
00:32:23,047 --> 00:32:25,430
(dolphins clicking)
448
00:32:25,430 --> 00:32:28,000
They can even fire pulses of sound
449
00:32:28,000 --> 00:32:32,357
into the silty sea floor to detect hiding creatures.
450
00:32:32,357 --> 00:32:35,107
(playful music)
451
00:32:37,200 --> 00:32:41,290
It's believed that just like our medical ultrasound,
452
00:32:41,290 --> 00:32:45,124
dolphins can look into each other's bodies.
453
00:32:45,124 --> 00:32:47,874
(playful music)
454
00:32:48,860 --> 00:32:51,300
They can check one another's health
455
00:32:51,300 --> 00:32:54,383
and even look at unborn babies.
456
00:32:54,383 --> 00:32:57,770
(playful music)
457
00:32:57,770 --> 00:33:01,393
They can do the same to us, looking inside our bodies.
458
00:33:04,327 --> 00:33:07,077
(playful music)
459
00:33:12,260 --> 00:33:15,383
This one knows the lady has something hidden in her wetsuit.
460
00:33:17,310 --> 00:33:20,480
It's detected the different density of the camera,
461
00:33:20,480 --> 00:33:23,293
based purely on the echoes of its clicks.
462
00:33:26,630 --> 00:33:27,950
While dolphins and bats
463
00:33:27,950 --> 00:33:30,023
have harnessed the power of ultrasound,
464
00:33:31,300 --> 00:33:33,853
sound waves too high for our ears to hear,
465
00:33:35,780 --> 00:33:38,771
others go to the opposite extreme.
466
00:33:38,771 --> 00:33:41,770
(waves splashing)
467
00:33:41,770 --> 00:33:43,963
Whales, alligators,
468
00:33:46,690 --> 00:33:49,773
even giraffes, use infra-sound,
469
00:33:50,611 --> 00:33:51,820
(whale grunting)
470
00:33:51,820 --> 00:33:55,670
sounds that are so deep we can only hear them
471
00:33:55,670 --> 00:33:56,853
if we speed them up.
472
00:33:57,754 --> 00:34:00,587
(water splashing)
473
00:34:01,860 --> 00:34:04,500
The champions of this super sound wave
474
00:34:04,500 --> 00:34:06,173
might be elephants again.
475
00:34:11,880 --> 00:34:14,590
The very deep sounds can rumble through the earth
476
00:34:14,590 --> 00:34:17,603
or through water over very long distances.
477
00:34:19,940 --> 00:34:22,133
We can hear some elephant rumbles,
478
00:34:23,460 --> 00:34:24,993
but others are too deep.
479
00:34:26,470 --> 00:34:28,503
They just vibrate through the earth.
480
00:34:33,570 --> 00:34:36,560
Incredibly, they don't just use their ears
481
00:34:36,560 --> 00:34:40,093
for long distance chat, they feel their way.
482
00:34:44,950 --> 00:34:47,080
Lying their trunks on the ground,
483
00:34:47,080 --> 00:34:49,710
and using the rubbery and highly sensitive pads
484
00:34:49,710 --> 00:34:52,310
on their feet, they can feel the vibrations
485
00:34:52,310 --> 00:34:56,822
of other Ellie's rumbling as much as 15 kilometers away.
486
00:34:56,822 --> 00:34:59,405
(low rumbling)
487
00:35:00,710 --> 00:35:02,910
From these faint signals,
488
00:35:02,910 --> 00:35:06,180
it's believed the big-brained behemoths
489
00:35:06,180 --> 00:35:09,080
can triangulate where each other are,
490
00:35:09,080 --> 00:35:13,450
check in on who's about, proclaim territories,
491
00:35:13,450 --> 00:35:15,480
check out the dating scene,
492
00:35:15,480 --> 00:35:17,723
and warn of approaching danger.
493
00:35:19,477 --> 00:35:22,060
(low rumbling)
494
00:35:26,087 --> 00:35:28,337
All without lifting a foot.
495
00:35:31,320 --> 00:35:34,153
(water splashing)
496
00:35:37,585 --> 00:35:40,002
(low bellow)
497
00:35:44,840 --> 00:35:47,593
Like us, elephants enjoy caressing.
498
00:35:51,170 --> 00:35:53,753
(light music)
499
00:36:00,348 --> 00:36:05,348
Touch is another of the weird and wonderful senses we enjoy.
500
00:36:05,890 --> 00:36:09,433
This is perhaps the first, most ancient of the senses.
501
00:36:11,650 --> 00:36:14,493
Pretty much all organisms have a sense of touch.
502
00:36:16,330 --> 00:36:18,210
It helps them to avoid surfaces
503
00:36:18,210 --> 00:36:22,650
that are too hot, too cold, or too sharp.
504
00:36:22,650 --> 00:36:25,400
(playful music)
505
00:36:29,650 --> 00:36:31,920
They can sense pressure and pain,
506
00:36:31,920 --> 00:36:35,156
and so help organisms to avoid danger.
507
00:36:35,156 --> 00:36:37,906
(playful music)
508
00:36:40,000 --> 00:36:43,543
It's how spiders know when prey has landed in their webs.
509
00:36:45,530 --> 00:36:47,680
They feel the vibrations in the strands
510
00:36:47,680 --> 00:36:50,353
of silk with the tiny hairs on their legs.
511
00:36:51,549 --> 00:36:54,049
(light music)
512
00:36:57,982 --> 00:37:01,010
(bird chirps)
513
00:37:01,010 --> 00:37:03,150
Though nerve cells cover our bodies
514
00:37:03,150 --> 00:37:06,210
and all over the bodies of most organisms,
515
00:37:06,210 --> 00:37:10,450
detecting pain, temperature, texture, and pressure,
516
00:37:10,450 --> 00:37:15,450
some animals have senses that are much more finely tuned.
517
00:37:15,609 --> 00:37:18,192
(light music)
518
00:37:21,080 --> 00:37:23,962
Whiskers are an animal's feelers.
519
00:37:23,962 --> 00:37:26,545
(light music)
520
00:37:28,080 --> 00:37:30,530
While all are embedded in nerve endings,
521
00:37:30,530 --> 00:37:33,774
some are more sensitive than others.
522
00:37:33,774 --> 00:37:36,357
(light music)
523
00:37:37,960 --> 00:37:41,200
Manatees are covered in coarse hairs,
524
00:37:41,200 --> 00:37:43,283
especially around their muzzles.
525
00:37:45,920 --> 00:37:48,830
And these can detect changes in water temperature
526
00:37:48,830 --> 00:37:52,480
and pressure, helping them to navigate tides
527
00:37:52,480 --> 00:37:54,323
and maintain their body temperature.
528
00:37:58,020 --> 00:38:00,860
It's thought pressure changes help them to detect
529
00:38:00,860 --> 00:38:04,063
objects ahead of them so they can avoid a collision.
530
00:38:05,268 --> 00:38:07,935
(ominous music)
531
00:38:11,990 --> 00:38:14,850
This super sense is essential underwater
532
00:38:14,850 --> 00:38:17,063
and several species make the most of it.
533
00:38:20,420 --> 00:38:24,030
Crocodiles and alligators have thousands of little pores
534
00:38:24,030 --> 00:38:27,053
on their snouts that can detect vibration.
535
00:38:28,320 --> 00:38:31,293
And these can help guide them to the movements of prey.
536
00:38:34,116 --> 00:38:36,574
(water splashes)
537
00:38:36,574 --> 00:38:39,241
(ominous music)
538
00:38:44,230 --> 00:38:49,230
But the feel fanatics, the champions of touch, are seals.
539
00:38:49,263 --> 00:38:51,920
(playful music)
540
00:38:51,920 --> 00:38:54,340
Their whiskers have far more nerve receptors
541
00:38:54,340 --> 00:38:55,893
than any other animal.
542
00:38:56,763 --> 00:38:58,930
(playful music)
543
00:38:58,930 --> 00:39:03,200
In the murky seas, they use the fan of hairs like a hand
544
00:39:03,200 --> 00:39:04,500
to feel their environment.
545
00:39:08,180 --> 00:39:10,970
They are so sensitive that they can pick up
546
00:39:10,970 --> 00:39:14,480
pressure changes caused by the swishing of a fish's tail
547
00:39:14,480 --> 00:39:17,803
nearly 200 meters away, guiding them to their food.
548
00:39:19,195 --> 00:39:21,945
(playful music)
549
00:39:24,620 --> 00:39:27,574
Taste is another vital sense.
550
00:39:27,574 --> 00:39:29,800
(playful music)
551
00:39:29,800 --> 00:39:32,486
We use it to enjoy our food.
552
00:39:32,486 --> 00:39:35,236
(playful music)
553
00:39:36,750 --> 00:39:39,360
But for animals it can be essential,
554
00:39:39,360 --> 00:39:41,763
allowing them to taste when food has gone off.
555
00:39:42,716 --> 00:39:46,020
(playful music)
556
00:39:46,020 --> 00:39:48,640
For us and most other animals,
557
00:39:48,640 --> 00:39:50,713
it's all about taste buds on the tongue.
558
00:39:52,290 --> 00:39:55,683
We can only taste what we put in our mouths.
559
00:39:57,372 --> 00:40:01,372
(playful music slows to a stop)
560
00:40:06,620 --> 00:40:09,423
We have about 10,000 taste buds.
561
00:40:11,400 --> 00:40:16,110
But catfish have 175,000
562
00:40:16,110 --> 00:40:18,403
and they are not confined to their mouths,
563
00:40:19,270 --> 00:40:21,635
they are all over their bodies.
564
00:40:21,635 --> 00:40:24,385
(ominous music)
565
00:40:25,600 --> 00:40:28,693
Catfish can literally taste their surroundings,
566
00:40:29,740 --> 00:40:32,483
ideal for trying to find food in murky water.
567
00:40:33,725 --> 00:40:36,308
(light music)
568
00:40:40,610 --> 00:40:42,760
For all five of these senses,
569
00:40:42,760 --> 00:40:45,130
we have a taste of what it's like.
570
00:40:45,130 --> 00:40:47,880
(playful music)
571
00:40:51,130 --> 00:40:54,300
But some oddball animals have superpowers
572
00:40:54,300 --> 00:40:55,793
we can barely imagine.
573
00:40:57,830 --> 00:41:02,110
Infrared is something our thermal imaging cameras can reveal
574
00:41:02,110 --> 00:41:04,573
by reading the heat signature of animals.
575
00:41:06,160 --> 00:41:08,953
Warm blooded animals appearing warmer in color
576
00:41:08,953 --> 00:41:10,843
against the cool landscape.
577
00:41:12,950 --> 00:41:16,240
Incredibly, some snakes can do the same
578
00:41:16,240 --> 00:41:18,485
using only holes on their heads.
579
00:41:18,485 --> 00:41:21,235
(ominous music)
580
00:41:22,500 --> 00:41:26,090
Boas, pit vipers and pythons,
581
00:41:26,090 --> 00:41:29,260
like this Burmese Python, have pit organs
582
00:41:30,320 --> 00:41:32,754
the series of holes in their snouts.
583
00:41:32,754 --> 00:41:35,710
(ominous music)
584
00:41:35,710 --> 00:41:37,993
They read thermal radiation,
585
00:41:40,570 --> 00:41:44,017
the waves of heat coming from anything warm.
586
00:41:44,017 --> 00:41:46,890
(ominous music)
587
00:41:46,890 --> 00:41:49,350
They can use it to sense ground temperature
588
00:41:50,850 --> 00:41:53,933
and so find places to warm up or cool down.
589
00:41:56,560 --> 00:41:57,883
And it helps them hunt.
590
00:42:01,403 --> 00:42:04,570
(slow, ominous music)
591
00:42:12,150 --> 00:42:14,350
Even in complete darkness,
592
00:42:14,350 --> 00:42:17,410
they can gather enough information from the pits
593
00:42:17,410 --> 00:42:20,383
to build a mental image of the location of their prey.
594
00:42:23,955 --> 00:42:28,955
And accurately plan their strike. (snake hisses)
595
00:42:29,160 --> 00:42:31,910
(dramatic music)
596
00:42:45,950 --> 00:42:47,960
Senses are innate,
597
00:42:47,960 --> 00:42:50,653
they need a bit of fine tuning as species grow.
598
00:42:52,038 --> 00:42:53,230
(bird chirping)
599
00:42:53,230 --> 00:42:56,382
But these amazing gifts are born into us.
600
00:42:56,382 --> 00:42:58,060
(bird chirping)
601
00:42:58,060 --> 00:43:00,743
And can lead to the seemingly impossible.
602
00:43:04,300 --> 00:43:05,980
One of the most extraordinary
603
00:43:05,980 --> 00:43:08,633
occurs when young birds leave the nest.
604
00:43:11,940 --> 00:43:14,179
They are born to migrate.
605
00:43:14,179 --> 00:43:17,030
(playful music)
606
00:43:17,030 --> 00:43:19,340
Some will travel halfway around the world,
607
00:43:19,340 --> 00:43:22,584
but somehow they will do so alone.
608
00:43:22,584 --> 00:43:25,334
(birds chirping)
609
00:43:27,450 --> 00:43:30,450
They do not learn by following their parents.
610
00:43:30,450 --> 00:43:32,123
They just seem to know.
611
00:43:35,700 --> 00:43:40,620
A super sense, deep within, will tell them when to fly,
612
00:43:40,620 --> 00:43:44,710
how far and in what direction to get them
613
00:43:44,710 --> 00:43:47,133
to a safe place to spend the winter.
614
00:43:50,601 --> 00:43:53,351
(dramatic music)
615
00:43:57,860 --> 00:44:00,130
Scientists have caught and moved birds
616
00:44:00,130 --> 00:44:01,563
to different locations,
617
00:44:03,890 --> 00:44:05,890
places that they have never been before.
618
00:44:08,950 --> 00:44:11,720
And before release, tried many measures,
619
00:44:11,720 --> 00:44:13,800
such as keeping them in darkness
620
00:44:13,800 --> 00:44:16,870
and using magnets to block the Earth's magnet field
621
00:44:16,870 --> 00:44:19,373
to try and eliminate different cues.
622
00:44:21,510 --> 00:44:25,153
But the birds somehow always find their way home.
623
00:44:29,580 --> 00:44:32,330
There's evidence that from a young age,
624
00:44:32,330 --> 00:44:34,840
birds watch and learn to track the movement
625
00:44:34,840 --> 00:44:36,483
of the sun and the stars,
626
00:44:39,230 --> 00:44:40,530
building a mental compass.
627
00:44:41,555 --> 00:44:44,055
(light music)
628
00:44:45,488 --> 00:44:48,600
(birds chirping)
629
00:44:48,600 --> 00:44:51,203
They also remember landmarks,
630
00:44:51,203 --> 00:44:53,786
(light music)
631
00:44:54,700 --> 00:44:56,738
even following roads.
632
00:44:56,738 --> 00:44:59,783
(light music)
633
00:44:59,783 --> 00:45:02,616
(birds squealing)
634
00:45:03,570 --> 00:45:05,560
And there is good evidence
635
00:45:05,560 --> 00:45:09,252
they can build a mental map with their sense of smell.
636
00:45:09,252 --> 00:45:11,835
(light music)
637
00:45:12,950 --> 00:45:15,280
Sniffing the ocean to one side,
638
00:45:15,280 --> 00:45:17,153
a forest to the other and so on.
639
00:45:20,420 --> 00:45:23,343
Key features that can help guide them.
640
00:45:24,190 --> 00:45:26,690
(light music)
641
00:45:28,113 --> 00:45:30,863
(birds chirping)
642
00:45:34,528 --> 00:45:37,330
Birds' ears, eyes and beaks
643
00:45:37,330 --> 00:45:39,580
all have special connections to their brains.
644
00:45:42,631 --> 00:45:46,020
And there can be tiny traces of iron in their ears
645
00:45:46,020 --> 00:45:50,508
and magnate, a magnetic rock, in their beaks.
646
00:45:50,508 --> 00:45:53,091
(light music)
647
00:45:54,790 --> 00:45:56,450
These mean birds are born
648
00:45:56,450 --> 00:46:00,310
with the ability to read the Earth's magnetic field.
649
00:46:00,310 --> 00:46:01,920
It's strength growing stronger
650
00:46:01,920 --> 00:46:04,333
away from the equator and toward the poles.
651
00:46:06,031 --> 00:46:08,448
(fluttering)
652
00:46:14,164 --> 00:46:16,660
None of these traits can be solely responsible
653
00:46:16,660 --> 00:46:19,659
for navigating such vast journeys.
654
00:46:19,659 --> 00:46:22,909
(dramatic piano music)
655
00:46:24,616 --> 00:46:27,380
And they can't explain how young birds
656
00:46:27,380 --> 00:46:30,453
seem to know on their own to migrate and where to go.
657
00:46:31,721 --> 00:46:35,040
(dramatic piano music)
658
00:46:35,040 --> 00:46:38,203
Birds clearly have own built-in GPS system,
659
00:46:40,360 --> 00:46:45,006
but how this superpower is used continues to baffle us.
660
00:46:45,006 --> 00:46:47,310
(birds cawing)
661
00:46:47,310 --> 00:46:51,603
The furthest reaches of our super senses are mind blowing.
662
00:46:54,035 --> 00:46:56,785
(water bubbling)
663
00:46:57,830 --> 00:47:00,900
Many animals also have shocking skills
664
00:47:00,900 --> 00:47:03,063
when it comes to sensing electricity.
665
00:47:04,970 --> 00:47:07,833
All life gives off faint electrical charges,
666
00:47:09,480 --> 00:47:13,563
barely perceptible energy generated by functioning cells.
667
00:47:15,510 --> 00:47:18,873
And a few animals are fine tuned to detect it.
668
00:47:20,760 --> 00:47:23,143
Most famously sharks.
669
00:47:25,440 --> 00:47:27,610
Their snouts are covered in pores
670
00:47:27,610 --> 00:47:30,093
that contain Lorenzini jelly,
671
00:47:31,400 --> 00:47:34,833
perhaps nature's most powerful conductors of electricity.
672
00:47:37,230 --> 00:47:39,260
With this power, they can locate
673
00:47:39,260 --> 00:47:42,603
the pulsing muscles in potential prey.
674
00:47:42,603 --> 00:47:45,456
(playful music)
675
00:47:45,456 --> 00:47:47,867
It can run, but it can't hide.
676
00:47:53,970 --> 00:47:56,900
(birds chirping)
677
00:47:56,900 --> 00:47:59,883
There are other ways to monitor these little charges too.
678
00:48:01,210 --> 00:48:04,770
(birds chirping)
679
00:48:04,770 --> 00:48:07,913
Flowers can have a very slight negative charge.
680
00:48:09,476 --> 00:48:11,643
(buzzing)
681
00:48:13,827 --> 00:48:16,170
The hairy legs of bumblebees
682
00:48:16,170 --> 00:48:17,923
seem to be able to pick this up.
683
00:48:20,680 --> 00:48:24,690
As the bees fly, the tiny hairs pick up static,
684
00:48:24,690 --> 00:48:28,393
a positive charge and the polar opposite of the plants,
685
00:48:29,480 --> 00:48:32,352
enough to guide them to a flower.
686
00:48:32,352 --> 00:48:34,935
(light music)
687
00:48:36,450 --> 00:48:39,760
Bees also use the Earth's magnetic field,
688
00:48:39,760 --> 00:48:41,560
perhaps because of tiny traces
689
00:48:41,560 --> 00:48:44,003
of magnetite in their bodies to navigate,
690
00:48:45,950 --> 00:48:48,073
an inbuilt creepy crawly magnet.
691
00:48:49,712 --> 00:48:53,212
(light, inspiring music)
692
00:49:00,910 --> 00:49:04,030
Red ants have the skill too, and may even use
693
00:49:04,030 --> 00:49:07,940
the electromagnetism to detect earthquakes.
694
00:49:07,940 --> 00:49:11,300
(light music)
695
00:49:11,300 --> 00:49:13,760
They have been seen to batten down the hatches,
696
00:49:13,760 --> 00:49:16,123
preparing their mounds way ahead of the quake.
697
00:49:17,015 --> 00:49:19,682
(playful music)
698
00:49:20,989 --> 00:49:22,260
(waves crashing)
699
00:49:22,260 --> 00:49:24,280
One animal seems to combine
700
00:49:24,280 --> 00:49:26,410
many of these remarkable traits
701
00:49:26,410 --> 00:49:28,243
in one of the weirdest forms of all.
702
00:49:29,450 --> 00:49:32,680
(water bubbling)
703
00:49:32,680 --> 00:49:36,676
The unmistakable profile of a hammerhead shark.
704
00:49:36,676 --> 00:49:39,750
(ominous music)
705
00:49:39,750 --> 00:49:42,790
Its broad mallet of a head might be useful
706
00:49:42,790 --> 00:49:45,840
for pinning down prey like stingrays,
707
00:49:45,840 --> 00:49:47,493
but it also aids its senses.
708
00:49:48,611 --> 00:49:51,361
(ominous music)
709
00:49:52,260 --> 00:49:55,980
It creates a huge surface for electron receptors
710
00:49:55,980 --> 00:49:57,450
that can help it navigate
711
00:49:57,450 --> 00:49:59,563
by reading the Earth's magnetic field.
712
00:50:00,646 --> 00:50:03,396
(ominous music)
713
00:50:04,430 --> 00:50:07,940
And it spreads its eyes and nostrils far apart,
714
00:50:07,940 --> 00:50:10,523
giving binocular sight and smell.
715
00:50:11,380 --> 00:50:14,130
(ominous music)
716
00:50:18,440 --> 00:50:22,130
It might have better directional senses than other animals
717
00:50:22,130 --> 00:50:24,130
thanks to being something of an oddball.
718
00:50:25,091 --> 00:50:27,841
(ominous music)
719
00:50:32,660 --> 00:50:35,730
Super senses and the weird and wonderful animals
720
00:50:35,730 --> 00:50:38,193
that have them enrich the planet.
721
00:50:40,210 --> 00:50:41,813
But our noise pollution,
722
00:50:42,661 --> 00:50:45,494
(gulls squawking)
723
00:50:48,360 --> 00:50:49,523
light pollution,
724
00:50:50,855 --> 00:50:53,438
(light music)
725
00:50:57,170 --> 00:50:58,820
and chemical pollution
726
00:51:01,060 --> 00:51:04,030
are dumbing our senses and making it harder
727
00:51:04,030 --> 00:51:07,035
for animals to use their skills.
728
00:51:07,035 --> 00:51:09,868
(dramatic music)
729
00:51:12,330 --> 00:51:14,709
Let's encourage change
730
00:51:14,709 --> 00:51:17,542
(birds squawking)
731
00:51:19,030 --> 00:51:24,030
before the only place for superpowers is comic strips.
732
00:51:24,554 --> 00:51:27,054
(light music)
733
00:51:43,712 --> 00:51:47,351
(monkeys chattering)
734
00:51:47,351 --> 00:51:49,934
(light music)
53734
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