Placeholder Image

字幕表 動画を再生する

  • It's Thanksgiving time here in the U.

  • S.

  • Which means everyone is talking about turkeys, which is why we hear sideshow are not going to.

  • Instead, today's compilation features a bunch of other incredible birds from weird ones that smell like fruit to the kind of terrifying ones.

  • Because once you start looking, you'll find that there are a lot of amazing species out there.

  • But first up, one pretty much all of us think we know well, the humble pigeon, though it turns out pigeons are a lot more interesting than you probably give them credit for.

  • Here's a very young Hank to explain.

  • We all know the white Dove is a symbol of peace and purity.

  • So what?

  • The pigeons symbolize dirt and disease?

  • Well, problem here.

  • Pigeons and doves.

  • Same thing just turns out.

  • One is a slightly better dressed Doves and pigeons are both members of the same family.

  • Columba Die, who's 308 species, could be found pretty much any place on Earth except Antarctica, and they come in a variety of sizes and colors since the dodo disappeared.

  • Yes, dodos were pigeons.

  • The turkey sized ground pigeon is the biggest of the family while the sparrow sized a new world ground dove is the smallest.

  • Now you have most definitely seen some kind of pigeon in your life.

  • But did you know pigeons produce milk?

  • They don't lack Tate like mammals, but they do produce a similar milk like substance to feed their chicks.

  • Now, if this sounds bizarre, it's because it is.

  • All pigeons do it, but they're joined only by flamingos and male emperor penguins.

  • In this ability crop Milk is a fat and protein rich substance produced by both male and female pigeon parents.

  • The milky white stuff is turned up in the birds crop or throat pouch, usually used for food storage.

  • The crop changes in response to hormones when eggs hatch in like a memory gland enters a sort of lactation period.

  • Pigeon milk contains tons of antioxidants and plays a key role in boosting chicks.

  • Immune system, much like mammalian breast milk does also Hitchens bob their heads to see better.

  • Lots of birds bob their heads as they strut around looking like Mick Jagger, and pigeons are no exception.

  • The head bobbing probably helps the birds stay balanced on their legs, which spring out fairly far back behind their bodies.

  • But researchers think this kind of jiving has more to do with stabilizing the vision.

  • We humans can't stabilize their vision with our eyeballs.

  • They stay in the same place when I move my head around, and unless we're really feeling the Dr Dre, we don't need to bob our heads while we walk.

  • But pigeons have a harder time multitasking in a busy world.

  • It's easier to observe a moving object when your head is still.

  • So when a pigeon bobs its head, it's actually holding its head in place temporarily while its body moves and then thrusts its head forward again.

  • This keeps the head stable for as long as possible so the pigeon can keep an eye out for a squirmy insects or swooping hawks.

  • We know this because in the late 19 seventies, creative ornithologist Barry Frost put some pigeons on a treadmill to see what happened and in the controlled surroundings of the lab, with no bugs or birds or pray to watch out for the bird's heads didn't bob third thing.

  • Pigeons are decorated war heroes with excellent hearing.

  • People have been using homing pigeons to deliver messages for centuries Persian Kings used them.

  • Julius Caesar used them in World War soldiers on the front used them to relate hundreds of thousands of messages.

  • One famous fire named Share on Me single wing Italy, saved a battalion of 600 trapped French soldiers flying home with a missing I ah, bullet in its breast and a leg dangling by a thread.

  • Share eventually healed and was awarded with the prestigious service cross.

  • When he finally died years later, he was stuffed and mounted and now resides at the Smithsonian Institution.

  • Humans have never quite understood homing pigeons ability to find their way home across large distances.

  • But a reason theory may have solved the mystery.

  • USGS researcher Jonathan Hagstrom believes that the birds use low frequency sound waves to create a sort of acoustic bath by which to navigate home pigeons can here, down to the faintest of infrasound noises down to even about 0.1 hurts, whereas even under the best laboratory conditions humans can't hope to hear under 12 hurts.

  • Eckstrom got the idea that the birds used sound frequencies when he noticed racing pigeons going astray whenever the supersonic Concorde jet was flying nearby.

  • The jets sonic interference was disorienting.

  • The pigeons, whether landscape and atmospheric changes, can also lead the birds of stray.

  • So, yeah, pigeons turns out they're pretty rads.

  • Be nice.

  • Looks like I need to give pigeons a bit more credit, though.

  • If we're going to give them credit for us.

  • I'm hearing this.

  • Next bird should get some kind of metal or something because it uses its stellar hearing to see Hank tell everyone about the incredible oil bird in the tropical rainforests of South America.

  • There's a flying animal that lives in colonies in caves, emerges at night and search for food and navigates using echo location.

  • And I'm not talking about a bat.

  • Believe it or not, I'm actually talking about a bird.

  • The bizarre oil bird known to locals as the Gua Ciara Oil birds diverged from their closest living relatives 50 million years ago, and in a lot of ways they've become more like bats than other birds.

  • They roost high up in caves, for example, one oil bird colony can include as many as 20,000 crow sized birds, and since there's not a lot of nesting material available in a cave, they build their funnel shaped nests out of a mixture of regurgitated fruit and their own feces.

  • Sounds cozy.

  • Yeah, and like a lot of nocturnal animals, including many bats.

  • For the record, they have excellent night vision.

  • They accomplish that by packing their retinas with rods.

  • The light receptor is responsible for vision in dim lighting.

  • In fact, oil bird retinas have the highest density of rods of any known vertebrate, one million of them per square millimeter.

  • Your retina has a max of about 150,000 rods per square millimeter.

  • These birds have so many rods that there's almost no room left over for cones, the other light receptors, which handle visual acuity and color.

  • That means that their view of the world is probably fuzzy and dull.

  • Even the world record holder for rod density needs some light to see, though, so that bird's eyes are no help in pitch black caverns.

  • Which might be why they're the only birds that have figured out how to echo locate to keep from getting confused.

  • In a densely populated cave, each bird clicks at a slightly different frequency, and, unlike bats, oil birds cliques are audible to human ears.

  • So If you were standing in one of these caves when the birds return to rest, you'd hear quite the cacophony.

  • Oil Birds Resemblance to Bats is a classic example of convergent evolution, where different animals facing similar pressures from natural selection end up with similar traits there so bad like that, you would think we called them bat Birds.

  • But if you're wondering where that name came from, yes, there's a story there.

  • Oil bird comes from the fact their favorite food is the fatty fruit of the oil palm.

  • Baby oil birds in particular, becomes so plump from their palm rich diet that indigenous people in Venezuela used to collect chicks so they could render their fat in pots to uses fuel.

  • You know, the more I think about the more I like Bat birds instead, maybe it's time for like a rebranding.

  • While we're on the subject of birds that have mastered darkness, let's talk about owls.

  • Owls have evolved some pretty impressive adaptations to rule the night, and here's a look.

  • It's Hank again with the details.

  • As animals go, owls are pretty awesome.

  • I mean, just look at Hedwig.

  • There are about 200 owl species on earth and you'll find them on every continent except Antarctica.

  • They could be a small is the sparrow sized else owl or is huge, the eagle sized great gray and most are nocturnal loners with broad heads on upright stance, big front facing eyes and gnarly talents.

  • Many cultures associate owls with either wisdom or death, and they aren't quite as bright as, um, other birds like crows.

  • Ravens.

  • The death thing might not be so far off, because if there's one thing owls are really good at, it is killing things quietly.

  • You might even say that they're the ninjas of the bird world, equipped with some unique adaptations that make them experts at both hunting and getting there creep on.

  • Let's start with their feathers, for example.

  • Maybe you've been out walking at some point, and you heard some washing sound.

  • Only look up and see a bird flying overhead.

  • Well, odds are, that was not an owl making that noise.

  • Most birds have smooth, sleek primary feathers, which create a noisy kind of turbulence is their wings collide with the air, and that's fine.

  • If you're a plant eating goose or, say, a falcon who's so fast.

  • It doesn't matter of your pre hears it coming because they're already toast but to a night hunting.

  • Owl catching dinner is all about stealth, so their feathers air specially adapted to reduce that air turbulence and the noise that comes with it.

  • Instead of a smooth, stiff leading edge and owls, primary feathers look more like comb, so serrated edges actually break up the air as it hits the wings, creating a bunch of smaller, less new, easy disturbances in the air.

  • And even those get buckled by a softer fringe of the trailing edge of the wing.

  • But Al's also come equipped with an extra silencer.

  • They're smaller down feathers, which absorb whatever noises.

  • Leftover magic feathers are awesome and all, but probably the first thing you'll notice about an owl are.

  • They're ridiculously huge front facing eyes, which can weigh up to 5% of their body weight.

  • All the better to see you with.

  • Because most owls are nocturnal, their eyes need to be good at processing whatever light is available, so allies have large corneas and pupils that allow extra light to enter the eye and funnel back into the image forming retina and compared to many other birds, Our retinas contain more of the light sensitive rods that help them see in low light conditions.

  • Plus the front facing set up, Let's hours look forward with both eyes, giving them a wider range of binocular vision than most birds.

  • It also helps them judge distance and dimensions, kind of like how humans do, it said.

  • It is not easy to squeeze such big eyes into a comparatively small skull, so allies aren't round like a typical eyeball.

  • Instead, they're more elongated in tube shaped.

  • They're also fixed into their sockets by rings of bone called sclerotic rings, which means owls can't roll their eyes.

  • And if they want to look to the side, they have to turn their whole head.

  • That said, Contrary to popular belief, no owl can go full Linda Blair and rotate their head all the way around so they can rotate them 3/4 of the way in either direction, which is still pretty impressive.

  • I mean, imagine looking to your right by turning your head all the way that you left.

  • It's hard to picture for a good reason, because if you tried it, you would either cut off the flow of blood to your brain and have a stroke, tear an artery or simply snap your neck.

  • And in any of those cases, you would be dead.

  • So you know, don't try it.

  • But how come owls conducive that?

  • Well, for starters, they have more vertebrate in their next 14 compared to our seven, and their heads are connected to their next by just one pivot joint, as opposed to our to this single joint gives the bird's head much more flexibility, allowing it to pivot its head on the vertebral column.

  • Sort of like how you can pivot your body on one foot.

  • Those neck bones also feature extra large holes about 10 times larger than the artery that passes through them and probably hold air sacs that helped cushion that fragile artery while the owl twists its neck so it doesn't tear it.

  • In 2012 a research team from Johns Hopkins discovered that there's more to the owl neck rotation puzzle.

  • They found that while most animals arteries typically gets smaller, the further they are from the heart on owl's main neck artery actually gets a little bigger as it nears the brain ballooning out tells larger areas might act is reservoirs storing a little extra blood descended the brain when the main vessel gets temporarily blocks during Maur extreme neck rotation.

  • So here's to Hedwig and all her other fellow Al's Master Ninja Birds of the night.

  • As cool as night Ninjas are.

  • The birds in our next episode have mastered an impressive hunting trick we once thought was unique to our species.

  • They use fire to capture their prey seriously.

  • And here's Stephan to tell us about nature's arsonists.

  • The Fire Hawks.

  • It's no secret that birds can be pretty smart.

  • You've probably heard of birds using tools or solving puzzles, but in Australia they take things to the next level.

  • There.

  • Some birds are said to intentionally start fires, making them the only animals besides humans known to do that.

  • Most animals don't like being near fire.

  • The standard instinct around flames is to drop what you're doing and run.

  • But some birds of prey do just the opposite.

  • If they spot a wildfire, they'll actually fly towards it.

  • They've figured out that fire causes little critters to panic and flee, making them easy targets as long as the birds were careful not to get burned.

  • A fire can mean an easy meal.

  • This incredible behavior is called fire foraging, and it's been seen in predatory birds around the world.

  • But in Australian Tropical Savannah's, some birds seem to take this strategy a step further.

  • They're known as fire hawks because they're said to fly into active fires, carry away a burning stick in their beak or talons, and then drop it into dry brush to start a totally new fire.

  • There's a lot we don't know about this avian arson.

  • It's never been reliably captured on photo or video, but this story's traced back generations around the world.

  • There are human cultures that have lived alongside native wildlife for hundreds or thousands of years, and these cultures can be a valuable source of what's called indigenous ecological knowledge.

  • In a 2017 study set out to collect this local knowledge, most stories identify three species as the arsonists, black kites, whistling kites and brown falcons, though there may be other birds that do it, too, and the team found that at least 12 different ethnic aboriginal groups reported firsthand knowledge of fire spreading in these birds.

  • They're even in some of their religious ceremonies.

  • One account goes as far as to suggest that early aboriginal people may have learned the trick of fire foraging by watching the birds.

  • The study also collected observations from non aboriginal people, including modern day firefighters.

  • As you can imagine, birds that can start fires could be a real pain if your job is to control blazes.

  • So local firefighters are often on the lookout for the birds.

  • One firefighter reported an instance where he spent an afternoon putting out seven different fires started by kites and another witnessed a group of birds start a fire that burned so out of control that a damaged a local cattle station.

  • In total, the study found accounts of fire spreading from West Australia, Queensland and the Northern Territory, a total area of thousands of square kilometres, so it may not be video footage, but it's pretty comprehensive ethno ornithological evidence that is cultural knowledge of birds, that the behavior still hasn't been scientifically observed and documented, so the researchers aren't done yet.

  • They plan to conduct more interviews, set up field experiments and equip local rangers with the tools to catch the birds in the act and all that will hopefully reveal how often the birds start fires and how firefighters can best plan around the behavior.

  • And it may even help researchers figure out how they learn to do it in the first place.

  • Firehawk will forever be the most hardcore name ever given to a bird.

  • It's just so metal, even though they're kind of sweet compared to the birds in the next episode.

  • Goals, yes, those big things that like to steal food from your beach picnics if you thought they were just annoying.

  • Well, Hank has some news for you when you're out of joint like a nice picnic on the beach, you might occasionally find a gold trying to grab some of your chips and you get Just stop bothering us.

  • You know, we'll just imagine for a moment that instead of your picnic basket, those girls were after your your flesh.

  • Because one particular species of Goa has recently developed a taste for live mammal meet, revealing just how adaptable these animals are.

  • Most girls eat fish or invertebrates like crabs, though they'll occasionally snack on carcasses.

  • If they wash up, they're considered generalised, opportunistic feeders.

  • They'll pretty much take whatever they can get.

  • But in the past 50 years or so one species, the kelp gull has developed a fondness for mammalian flesh and learned just how to get it.

  • It all started in Peninsula Valdes, Argentina.

  • Ah, birthing ground for Southern right whales, giving birth is exhausting for everyone involved.

  • So both new mamas and their babies like to relax and rest near the ocean surface.

  • And that's precisely when the goals attack these half a meter long, Roughly one kilogram birds land on the whales, backs and peel off pieces of skin until the wound becomes big enough that they can dig into the blubber underneath gross and mean.

  • They mostly attacked calves because the babies haven't learned howto arch there back or flick the goals off like their moms have.

  • But what's really terrifying is that the goals hunger for flesh is growing stronger.

  • Between 2003 and 2014 more than 50 calves died per year, on average involved as compared to only eight per year in the decade before.

  • People aren't 100% certain that all of those deaths were caused by gulls, but scientists have noted an increase in the number and severity of attacks.

  • The percentage of whales with gull inflicted wounds rose from 2% in the 19 seventies to a gruesome 99% of the two thousands, according to a 2015 plus one study.

  • And the situation is now so bad that the goals are considered a significant threat to right whale populations in the area.

  • These guys got to smart.

  • So since 2012 local governments have been culling some of the murder birds to try and protect the whales.

  • But it's not just Argentine ian whales that I have to keep an eye on the skies.

  • Help Goals in Namibia have recently discovered a taste for baby first seal eyeballs like something out of Alfred Hitchcock's The Birds.

  • The goals will repeatedly swooped down and pecked out the eyeballs of unattended cape first seal pups until the pups go blind.

  • Once they're unable to Seymour gulls join in the feast and packet the juicy way.

  • I'm just gonna stop that.

  • I'm gonna read with the script, even says it's too sad.

  • Let's just say the pups don't make it.

  • And since we've only known that goals air preying on seal pups since 2014.

  • No one knows yet if seal numbers will be affected.

  • These chilling behavior is likely developed in part because girls have such a generalist diet, but also because they're quite good at observational learning, meaning they can learn new behaviours just from watching other goals.

  • So just a few likely discovered that squishy eyeballs and hunks of blubber are great sources of protein, fat and fluid, and others quickly caught on to the new snacks, which explains why the behaviors air pretty much only seen in the same areas they began, though they could spread.

  • And we might also be to blame for the increase in the goals murderous behavior because of our activities.

  • Their usual prey is harder to come by, but this hasn't hurt their numbers as thes flexible birds have learned that our refuse is full of potential food.

  • So unlike many species, they do well in the places we've figuratively and literally trashed.

  • I guess we should count ourselves lucky that they haven't figured out what human eyeballs taste like yet.

  • Just have it.

  • Have a chip, have a chip.

  • It's fine.

  • You can have my chips.

  • Well, looks like I'm never going to the beach again.

  • I need a bit of a palate cleanser after that horror show.

  • So how about some pretty fragrant seabirds?

  • The definitely not goals in the next episode have a delightful sent to them, but enough for me.

  • I'll let Hank explain what's going on.

  • On the remote rocky islands of the North Pacific.

  • You might find, ah, happy looking little bird called the crested Chocolate.

  • It looks kind of like a cross between a penguin and a quail.

  • They live in big, dense, noisy colonies and then go out to the ocean to feed.

  • They also apparently smell like tangerines.

  • Smell, which has been described as distinctive and pungent, emerges at the beginning of the breeding season.

  • As for what's actually causing it, the smell seems to come from a mix of compounds secreted by a patch of special hair like possibly hollow feathers called wick feathers, found on a particular area of skin on their back.

  • It has got a little tangerine patch back there.

  • The mix of compounds is dominated by Aldo hides, a kind of chemical that contains a carbon bonded to a hydrogen and double bonded to an oxygen.

  • As for why there are two hypotheses.

  • One is that the smelly Aldo hides might be a way for the birds to repel parasites like lice, kind of like a built in can of bug spray.

  • Experiments have shown that some of the compounds in the smell can repel or paralyzed ticks or lights.

  • The other ideas that it might be some kind of sexual display or some other sort of social signal during courtship crested Aqel its approach potential mates and bury their bill in that patch in what's known as a rough sniff.

  • And they can definitely smell it.

  • Studies have shown that the birds comptel the scent apart from other smells and even appeared to be attracted to it when presented with a smelly fake bird, which is Connie.

  • Because for a long time many experts thought birds couldn't really smell things.

  • That idea was debunked by scientists in the 19 sixties and that research doesn't have much of anything to do with crested chocolates.

  • But as a myth, it's had surprising staying power might seem kind of funny, but choosing the smelliest mate might have some benefits.

  • If the scent is a parasite repellent, for example, a smelly mate is less likely to pass infestations do there mate or their offspring?

  • The smell might also be an indicator of how healthy the animal is.

  • In general, it's body has to produce those smelly chemicals, which requires energy, and because all smells eventually fade over time.

  • An animal that depends on cologne to win a mate has to keep making new compounds all the time.

  • Which means it has the energy to burn to make smelly molecules, even though those resources could be used for other, more survival oriented things.

  • This means for Crested Auckland's, a strong scent might be a way to show that you're not only healthy, but you have the resources to burn.

  • And finally, let's talk about birds that can talk like us parents.

  • Ability to speak is really impressive, and Olivia is here to explain how they manage to do this thing that even our closest relatives can't do.

  • Parents have an uncanny ability to mimic human speech.

  • They're mad vocal skills, have let them co host Ted talks, sing in heavy metal bands and made them the pet of choice to deliver punch lines and pirate movies.

  • Heart of This is just being able to make the sounds that we d'oh hair.

  • It's have articulate tongues, which can move around in their mouths and shift frequencies to make human like vowel sounds that mostly parents have unique brains when the majority of birds chirp or saying they're making noises that are hardwired.

  • But parents can create new vocalizations, which scientists it's called vocal learning.

  • Not only that, but something about their neurons make them incredibly good at vocal mimicry, replicating the sounds or calls of other species.

  • Only three types of birds are capable of vocal learning hummingbirds, songbirds and parrots.

  • Scientists don't know exactly how vocal learning helps them.

  • Butt freestyling might let different groups of birds tell each other apart, which could help them identify enemies and form strong social bonds despite being very different.

  • Birds humming birds, songbirds and parrots all have seven clusters of neurons in their brain called song nuclei.

  • Since other birds don't have these brain regions, scientists think they've got to be behind vocal learning.

  • The song nuclei are surrounded by or next to parts of the brain that control movement, the ones involved in learning or towards the front of the brain and those involved in sound production are further back.

  • But just having sung nuclei doesn't explain why parents are so much better at well parroting speech.

  • Now, most research on mimicry and parrots uses the common parakeet, or budgie, as a model for the whole group.

  • But in 2015 researchers took a look at the brains of a bunch of different parrots and found that they all had something that hummingbirds and songbirds didn't an extra layer or shell surrounding each nucleus.

  • It's a bit like the candy coating on a skittle.

  • Parents have the full candy, while other birds just have the fruity core.

  • And differences in the amount of shell seem to correlate to mimicking abilities.

  • Expert imitators like the African Grey Parrot have much larger shell regions and smaller cores, then copycats who are less skilled, like budgies and peach face lovebirds.

  • So far, it's just a correlation.

  • So these shells may not be the reason or the only reason why parents are super mimics, not to mention Scientists don't know how the shells function right now, although they know that the shells linked to each other and make different connections than the course based on similarities in the types of genes expressed in each brain region.

  • Scientists think that this double layered song system may have come about because song nuclear I got duplicated more than 29 million years ago.

  • We humans didn't gain are refined linguistic abilities until millions of years later.

  • So when it really comes down to it, who's mimicking whom?

  • Thanks for learning about these amazing birds with me.

  • We'd love to hear about which was your favorite and why in the comment section.

  • Also, since it's the last week of November, I want to remind you that it's the last week to get this month's I show up in.

  • Every month we have a new design, and this month it's Maron, or nine that rhymed.

  • Anyhow, come December 1st will have a whole new pin for you.

  • So if you want this one either for yourself for a space fan in your life, you'd better get your soon.

  • Just head over to D.

  • F.

  • T B a dot com and search for the sideshow pin of the month.

It's Thanksgiving time here in the U.

字幕と単語

ワンタップで英和辞典検索 単語をクリックすると、意味が表示されます

B2 中上級

地球上で最もクールな鳥たち|SciShow総集編 (The Coolest Birds on Earth | A SciShow Compilation)

  • 11 1
    林宜悉 に公開 2021 年 01 月 14 日
動画の中の単語