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Uploaded:2020-11-26
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You probably don't think much about birds most of the time, but these little former-dinosaurs are amazing! So, here's a collection of videos in which we've tackled our viewers' biggest bird questions!

Hosted by: Michael Aranda

SciShow has a spinoff podcast! It's called SciShow Tangents. Check it out at http://www.scishowtangents.org
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Original Episodes:
Why Do Birds Sing in the Morning?
https://www.youtube.com/watch?v=0Je4kpqv1g4

Why Do Flamingos Stand on One Leg?
https://www.youtube.com/watch?v=2pXxq4oMlCU

Why Don't Penguins' Feet Freeze?
https://www.youtube.com/watch?v=Nztud0JFStM

Why Don’t Birds on Power Lines Get Zapped?
https://www.youtube.com/watch?v=cxjZtRZj64g

What Happens to Birds During Hurricanes
https://www.youtube.com/watch?v=DNvJ4E3mw9Q

Why Don't Birds Have Vertical Tails Like Airplanes?
https://www.youtube.com/watch?v=sLCiDObJY0s

Michael: Just about anywhere you are, you can probably stick your head out the window and either see or hear a bird. And while most days you might not think much about them, these little former dinosaurs flying over our heads all the time... are kind of amazing. 

So, over the years, we've made a bunch of videos about them, and here we have put together some of the ones tackling our biggest questions about birds. First, if there is one thing birds are famous for, it's for bursting into song even before the crack of dawn. Which might not be a time when you have ever felt like singing, but it turns out birds have a good reason for it. Here's what it's all about. 

   Why do birds sing in the morning? (0:42)


You might have heard that the early bird gets the worm, but some times of the year it seems like they sure are noisy about it. So why are some songbirds so chirpy in the morning before the sun's even out? Turns out these birds sing in the morning to get the crispest, clearest sound quality they can. 

But before I can explain that, we gotta get on the same pages about bird noises. A bird call is typically a short sound like a chirp or a squawk that all birds of the same species are born knowing how to make to say things like hey, I'm over here or danger! But the morning music you often hear is birdsong, which is a longer, more complex pattern of notes. 

Usually, male songbirds sing, though scientists have found that many females can carry a tune too. And most young birds have to learn their songs by copying an adult. 

Males might sing to attract a mate, but mostly it's to tell other males to back off their territory. So as lovely as their songs might sound to us, the message isn't always so sweet. 

So that's why songbirds sing... what about the when? While you might hear bird calls at any time of year, you're more likely to hear birdsong in the spring. And these songs are louder and more frequent during the wee hours of the morning. 

Scientists call this phenomenon the "dawn chorus," and they think it has to do with the clarity of the sound. When the sun rises, it heats the ground and in turn the air. As the day goes on, the warm air rises, mixes with layers of cool air, and creates atmospheric turbulence: lots of pockets of air molecules moving around at different speeds. 

This turbulence interferes with the birdsong broadcast, making the sound less clear. 

Since male songbirds of the same species can sing slightly different versions of the same song, clarity is key if a guy wants to set himself apart from the others and make sure he reaches the ladies. And it's easiest to send a clear, complex message in the morning, when there's not much atmospheric turbulence. 

Plus, singing in the morning means that a male songbird not only survived the night, but he has the time and energy to sit and sing instead of foraging for breakfast right away. So this can make him seem like a healthier, more attractive mate.  

 Studio Intro (2:26)


I mean, I guess it's nice to know that they're not just flaunting the fact that they're so good at getting up in the morning. But their knack for getting up early is definitely not birds' only strange habit. 

Like, many of them spend a lot of time standing on one leg, including flamingos. It seems uncomfortable and scientists aren't totally sure why flamingos do that, but they have one pretty good idea. Here's Hank with more. 

 Why do flamingos stand on one leg? (2:48)


Why do flamingos stand on one leg? It may sound like some kind of animal cliche, or even a misconception, like the belief that ostriches stick their head in the sand, but lo! It turns out that flamingos not only really do support themselves on a single leg much of the time, as do many other birds, but the behavior is peculiar enough that scientists have struggled to explain it. 

There are a bunch of different theories, one of which is that the birds are simply resting one of their legs so they're more limber and can get a running start if a predator approaches.

However, a study of captive flamingos at the Philidelphia Zoo in 2009 found that flamingos resting on one leg were actually slower to get started from a standstill than the birds that were standing on two. 

So scientists kept observing in the hopes of finding more clues. Finding, for example, that it is done both males and females, that the birds don't show a preference for standing on one leg or the other. But they did discover that flamingos are significantly more likely to stand on one leg when they're standing in water, than when they're standing on land. And the behavior was much more common in cold weather than warm. 

So the prevailing theory is that flamingos stand on one leg to regulate their body temperature. Even in tropical climates where flamingos naturally live, water wicks away much more body heat than air, so limiting the amount of body mass that's under water can help the birds stay warm and conserve energy. 

It's kind of like they are just taking one leg and stuffing it up into their warm, cozy, fuzzy body feathers. Like, they are sticking it in their pocket up there. It's cute.

 Studio Intro (4:06)


A built-in foot pocket actually sounds pretty cozy. But speaking of birds with cold feet, if water is so cold for birds, then that raises a question. Why don't penguins' feet freeze after walking on ice all day? Here's Hank again to explain.

 Why don't penguins' feet freeze? (4:22)


It's like, really, really cold in Antarctica. It can get way below negative 30 degrees Celsius. Plus, everything's covered in ice and snow. So how about taking a hike across it... barefoot? That is a day in the life of a penguin. In fact, the whole life in the life of a penguin. And yet somehow their feed don't get hurt. Or freeze. The trick is they have special adaptations to keep the blood in their feet just barely above zero degrees Celsius, while keeping the rest of their tissues nice and warm. Antarctic penguins keep their bodies warm with thick layers of fat and downy feathers. But their feet are designed for swimming and walking on slippery ice.

They're webbed with lots of surface area and no feathers. So it's really easy for them to lose heat, but penguins have a couple of tricks to keep their feet safe in the cold. First, the muscles that control their feet are tucked up in their warm body for protection, and are controlled by strong tendons to the feet bones. Kinda like a foot puppeteer.

Not to mention, penguin feet are tough. They're mostly made of bone and keratin, the same protein as our fingernails. And when it gets really cold, some penguins will lean back onto their heels and curl their toes to keep them off the frozen ground. But the real secret is, penguins keep their feet just above freezing temperatures using something called "countercurrent heat exchange".

At the top of each foot, the penguins' blood vessels wrap around each other. So, different temperatures of blood are flowing in opposite directions, or countercurrent. This allows heat to transfer from the warm blood entering the feet to the cold blood headed back to the central body. So by the time the blood gets down to the feet with all the oxygen for the cells, most of the heat has already been carried back up, to keep those important muscles and organs warm.

This way, the penguins' feet stay just warm enough to keep them from freezing and they're not wasting a bunch of energy trying to heat up their feet to body temperature. Humans actually use countercurrent heat exchange too, although our blood vessels don't actually wrap around each other. This means that, on a cold day, the blood going to your fingers and toes is actually a little cooler, to save a little heat and keep your central body warm.

But our skin, of course, is not as though as penguins' feet, so your fingers and toes can get damaged by the cold much more easily. So, even for the daredevils among us, I would not recommend any barefoot tricks across Antarctica.

 Studio Intro (6:36)


Speaking of birds with super tough feet, maybe you've wondered what's the deal is with those birds like to hang out on power lines. Livewires are definitely not something you wanna mess with, but, weirdly enough, there's nothing special about birds' feet that lets them perch on power lines without getting zapped. So, physics. Livia has more on that.

 Why don't birds on power lines get zapped? (6:55)


Many of us learned that electricity can be dangerous back when we were toddlers. You know that tiny try to stick a fork into an electrical outlet and all the adults in the room freaked out? Compared to a standard outlet, overhead power lines carry a lot more electricity. So, touching them is an an even bigger no-no. But that doesn't explain how birds perch on power lines all the time without getting zapped. Besides being way more dangerous, overhead power lines usually aren't even isolated, like the cords on our appliances. Well, it's not because birds have some sort of superpower. Instead, it turns out that the reason they can sit on power lines has to do with how electrical currents and circuits work. 

Electric current is just the movement of electrons, specifically from an area with a lot of electrons to one with fewer.

Scientists describe that as moving from lower to higher potential.
If someone were to stick their fingers in an electrical outlet, electrons would travel through their body to get to a spot with higher potential, usually the ground. Which is why sticking your finger into a socket is a terrible idea. But, when a bird perches on a wire, they're totally fine.

That's because both feet are on the same wire. They're not in contact with an area of higher potential, like the ground. The electrons in the wire can't get to an area of higher potential by passing through the birds' bodies, so they don't, and since no current flows through the bird, it's unharmed.

But, say a bird moves one foot to a different wire with a different potential, now their body has formed a path for the electrons to move from low to high potential, also known as a circuit. Current flows through the circuit and it's bye bye birdie.

Now, thankfully, most birds don't have a problem with power lines, but some do get electrocuted. Typically, these are larger raptors like eagles, hawks, and owls. Often, these birds will perch on an electrical pole, then stretch out a wing, and brush it against the power line. That completes a circuit between the power line and the pole, which leads to the ground. 

Electrocution is usually fatal for birds, and scientists estimate that millions of them are electrocuted by power lines each year in the U.S. To protect larger birds, many utility companies are now implementing raptor-safe power pole designs. These include structures that discourage birds from perching on poles, or that leave more space between the pole and the charged wires, so birds are less likely to touch both at the same time. 

Electricity allows us to do amazing things, like reheat yesterday's pizza in under a minute, or watch SciShow, but it can also kill us and our feathered friends, so it's always better to leave the power lines to the professionals.

 Studio Intro (9:18)


Okay, so avoiding zappings from live wires isn't some special bird superpower, but aside from the fact that they can fly, birds do seem to have some other abilities that seem like superpowers.

Like many of them manage to survive really extreme storms, even storms that devastate the areas they pass through. And some of these birds weather the storms in the last place you'd expect. Here's another one from Olivia.


 What Happens to Birds During Hurricanes? (9:41)


The 2017 hurricane season sure packed a wallop. Three major storms -- Harvey, Irma, and Maria -- decimated the Caribbean and the southern US.

 While the focus has rightfully been on the impacts to those living in the storm’s path, you might wonder how other creatures fared. Some species seem to be able to sense the impending danger and flee.  (10:00) to (12:00) Landlubbers like us that don’t get out of the way just have to hunker down as best they can.


But birds and other airborne animals sometimes do what sounds like the worst idea ever: they ride things out in the eye of the storm. Meteorologists have witnessed this thanks to something called dual-polarization or dual-pol radar, which uses pulses of electromagnetic waves to detect the size and shape of objects in two dimensions. Based on the pattern of the waves, they can see the proportions of whatever’s in the storm — including birds and insects, which stand out because they’re much less spherical than, say, a raindrop.

And when meteorologists map out what they’ve detected with radar, they often find a bunch of animals inside the eyes of big storms. Heading into a hurricane for safety sounds pretty bold … and ill-advised. But within the eye, the weather is calm.

It’s a spot of extremely low pressure, which helps drive the overall storm, but isn’t very windy itself. It doesn’t even have clouds, since the air in the eye is about 5 degrees warmer than the rest of the storm, and it can hold more water before condensing. So, all things considered, it’s relatively safe for birds and bugs.

Not that it’s an intentional strategy on their part—they probably don’t plan this out. Either the eye forms around them, or they just happen to find the eye and then end up kinda stuck there. This especially happens with seabirds.

The real danger is running into the eyewall, the vertical wall of clouds that surrounds the eye, which is the most intense part of the storm. It has the heaviest rainfall and strongest winds. Sticking to the eye can work, but it can be tough to make it through if a hurricane is especially long-lived.

Trapped birds don’t have much choice but to keep flapping—they can’t really stop to sleep or eat—so this kind of travel can wear them out. Sometimes they die. And since, you know, a hurricane swept through their habitat, there may not be much left to come home to.

Or, if they’re migratory birds, they can be blown hundreds of kilometers off course. In 2005, Hurricane Wilma deposited a flock of North American chimney swifts in Western Europe. More than 700 of the birds died, and ornithologists found that the following year, the total population had been cut in half. =

It can be hard to collect good data on what happens to birds during and after a storm, as each hurricane is different. But birdwatchers can help with that. Safety first, obviously, but if you ever see “hurricane birds”—species well outside of their usual homes during or after a storm—you can report your observations so scientists can learn more about how animals deal with tropical cyclones.

It’s one of the more unusual types of citizen science. 

 Studio Intro (12:27)


Alright, but even if the eye of the storm is calmer than the rest of it, these birds are still flying in a hurricane, which means they've got to be pretty good fliers. So you'd think that airplanes might look a little more like birds, but our airplanes have some pretty important differences and designs.  Stephan's got more on why.


 Why Don't Birds have Vertical Tailes like Airplanes? (12:45)


I don’t know if you’ve noticed, but nature is kind of awesome. That’s why so much of our technology is inspired by it, from adhesives modeled after insects to early plane wings based on birds.

But just because we try to mimic nature doesn’t mean we can do it perfectly, and birds and airplanes are a pretty good example of our limits. Take the vertical tails on most airplanes. We use them to keep our giant, metal contraptions in the air and going the right way — but birds get by fine without them.

That’s because they’re just way better at flying than we are, and for the most part, we can’t keep up. The parts of an airplane all work together to keep the plane in the sky and facing the right direction. And thanks to all kinds of invisible air currents, that isn’t as simple as it looks from your window seat.

The vertical tail’s main job is to stabilize something called yaw. Yaw measures how much the plane is pointed to the left or right of the wind — specifically, the relative wind, which is created by the plane zooming through the atmosphere at hundreds of kilometers an hour. Yaw can change in lots of situations, like during turns or in unsteady air.

 And when it does, it occasionally leads to a condition called sideslip. This is where the plane has yawed, but it hasn’t completely changed its direction. Instead, it’s still mostly moving in the direction it was, only at a funny angle. Kind of like a sports car drifting around a turn. Normally, this just leads to a little inefficiency. But if it’s not corrected, sideslip can get out of hand. (14:00) to (15:30) If the plane yaws too much, it starts to affect how the air flows over the wings. And if too much air flows parallel to the wings instead of perpendicular, the plane can lose lift. Which, is kind of important for keeping it in the sky!


That’s where the vertical tail comes in. See, as the plane starts to sideslip, the side of the tail will start to face into the relative wind and become more perpendicular to it. And as the wind pushes on the tail surface, it creates a force that ultimately nudges the whole plane back to face its original direction.

Birds, meanwhile, don’t have to deal with all this because they’re way better at flying than we are. Which makes sense, considering they’ve had millions of years to work on it. They don’t need vertical tails for stability because they’re constantly making fast, tiny adjustments to the shape and angle of their wings, which lets them avoid sideslip.

Right now, that's just not something we can practically or easily do with airplanes, especially passenger jets. And even though there have been some planes without vertical tails — like the B-2 stealth bomber — they come with plenty of stability challenges. Engineers are definitely working on it, but it looks like nature has one-upped us for now.

 Studio Intro (14:58)


You have to hand it to birds, they've figured out a lot of tricks for getting by on this planet that are pretty admirable, and we're only starting to figure them out.  Thanks to all of our supporters who have helped us make these videos over the years,
including our patrons who continue to make these videos possible.

If you want to find out more about how you can help us keep scishow going, head over to patreon.com/scishow.

[Outro]