Abc.
Listen hello, my name is niche and today on, imagine this ah, a chicken.
How did you get here?
From an egg.
But then where did the egg come from?
From the chicken.
So then, what lay the egg?
That hatched the chicken?
That lay the egg?
A chicken.
It comes from the egg.
Hmm, this might take a while.
Yeah.
And how do they even make the eggs in the first place?
All the things that they eat get together and then it makes the egg.
I think they...
The egg rolls down in their body to different stations like a train set, stopping at each station, and then it gets made.
Pippa, Liam and William have asked about chickens and eggs.
Hi I'm Pippa and I'm three.
Hi I'm Liam.
I'm five years old.
Hello, my name is William and I'm seven years old.
And I want to know how chickens make eggs.
I want to know how do they lay eggs.
And I want to know which one comes first, the egg or the chicken.
There's a lot of things to think about.
I know who can settle this.
Professor Kate Buchanan.
She's an ornithologist, that's a bird expert.
I reckon she'll have the answer.
We're on a farm.
Look at all the chickens, aren't they lovely?
Hi professor, hi there hello, hi chooks.
Hey, we came to ask you about chickens and how they lay eggs, But do all chickens come from eggs?
Chickens absolutely come from eggs but just not the eggs that we buy at the supermarket.
Really?
How about we use our imaginations to follow the long journey of chickens and eggs?
That sounds like an egg-cellent idea.
We're in the jungle.
That's right.
We're in the jungles of Southeast Asia.
Did you hear something?
I think it's a bird.
Is that a rooster?
Hello, who are you?
This? is a red jungle fowl.
Jungle fowl?
It looks like a chicken.
That's because it's the ancestor of the chickens of today.
Ancestors are like what happened a long time ago with evolution.
Yeah, evolution is how animals and plants evolved, change over a long time to be different from their ancestors.
And it doesn't just evolve one thing, it evolves the whole species.
Yeah, so living things evolve to be better or stronger in their environments.
That's right, but the way that chickens evolved from rare jungle fowl is called domestication.
But we haven't heard of that word I don't think yet.
That's when wild animals or plants change when they are kept by humans for a long time.
Chickens don't exist naturally in the wild.
They were carefully chosen by humans to become the birds that they are now.
It's like how we got all the dogs we have today from wolves or the pigs that live on farms from wild boars.
All farm animals have a wild ancestor.
That's right.
But the jungle fowl looks pretty similar to a chicken.
It's just smaller.
The biggest difference is in how they make their eggs.
In the wild, the female jungle fowl's body starts to change when the seasons do.
As the days get longer and the weather gets warmer, the male jungle fowl starts to act differently too.
He might dig a hole.
And he gets super grumpy.
And then when other like jungle fowl roosters come along, he pushes them away and then starts pecking everything.
Oh, he's really strutting around.
He's walking all funny.
He starts to dance with the females and he crawls a lot.
Like a cock-a-doodle-doo.
After all his singing and dancing, the female and male jungle fowl will mate.
And then the female is ready to lay a clutch of eggs.
What's a clutch?
Well, that's the word for a group of eggs that's been laid by a bird.
How do they make eggs?
Well, it all starts with the yolk.
Is it the little circled thing in the milk?
It's the yellow part of the egg.
Yeah.
The yolk is made of fat and protein and it's made so that the baby bird can have something to eat while it grows inside the shell.
Does the baby bird pick at the yolk?
While it's growing?
Actually, it gets absorbed straight into its tummy.
Yeah.
Cool.
First, the yolk is made in a body part called the ovary.
And when it's big enough, it's released from the ovary and moves through a long tube called the oviduct.
Oviduct.
That's a funny word.
Ovi means egg and duct means tube.
So really, it just means egg tube.
Egg tube.
That makes sense.
As the yolk moves through the egg tube, layers of egg white are added.
It's called albumin.
Albumen.
Albumen.
Clear googly gobbly stuff.
It's mostly just water with a little bit of protein in it.
Why are they wrapped in a little blobby thing?
Yeah, if the yolk is to feed the baby bird, what is the egg white for?
Well, the egg white protects the yolk like a gooey soft barrier and helps support the little baby bird.
Ah, it's like a little pillow.
A warm blanket.
I would like to be unwrapped in a nice sheepskin.
Ah, comfy.
This all happens pretty quickly, within an hour or two.
Then the yolk and white move to the last section of the egg tube.
This part of the tube is shaped like an egg.
It makes the egg egg shape.
Now the egg is ready for the last and the longest stage.
Hatching?
Not yet.
The shell.
That's right.
I wonder what eggshells are made out of.
Calcium.
It's pretty hard, but we can easily crack it.
That's right.
The shell is made of calcium.
Ah, like our bones.
Like our teeth.
It's in milk and cream.
Or like a snail shell.
Yes.
At the end of the egg tube, there are tiny little jets that spray globs of calcium.
It's really cool how they just spray it and spray it and spray it.
I wonder if there's paint bottles in there.
Graffiti cans.
Layers and layers of these globs will land on top of each other.
The shell's growing.
The shell!
The calcium isn't being sprayed all over.
I can see teeny tiny gaps between the blobs.
Yes, that's so the egg can breathe.
Baby birds need to be able to breathe air through the shell.
The jets change for the last layer.
It's making colors!
Yeah!
Most chickens' eggs are brown, white or speckled, but other birds can make lots of colors and patterns on their eggs.
How about purple color?
Pink?
Blue?
Yeah!
Wow!
So the shell is coated on like layers of wet paint.
It takes about 20 hours for the shell to be sprayed on and hardened.
20 hours?
That's ages!
Yes, it takes a bit of time to harden.
But then, once it does, it's ready to be laid.
And then the whole thing starts all over again.
Again?
Straight away?
Yep.
Doesn't she need a break?
It would be like laying a baby every day.
That's a lot of eggs.
They'll need a lot of calcium.
In jungle fowl.
This happens every day for about 10 days, and then they take a break to look after their eggs.
So they lay 10 eggs.
10!
Yes, a clutch of jungle fowl eggs is about that size.
It can't be too many more than that, because the bird needs to be able to sit on them all to keep them warm.
So what's different about how jungle fowl lay eggs and the chickens we get our eggs from?
Today's chickens lay eggs every day, all year round.
They don't stop.
And that's partly because people noticed they could actually trick the birds.
Trick them?
How?
When people took away the jungle fowl's eggs, they noticed the jungle fowl would lay even more eggs to complete the clutch.
Ah, so people could keep taking the eggs to eat.
And I guess they didn't need this guy anymore.
The bird would keep laying them.
Yeah.
The jungle fowl that could lay the most eggs would be kept as pets.
And the best egg layers.
The birds that could lay the biggest, best egg, would pass that ability on to the next generation of jungle fowl.
After a while, very slowly, the jungle fowl that used to lay only 10 eggs over 10 days became chickens that never stopped laying them.
Now we have chickens that lay much larger eggs and they lay them all year round.
They don't need warm weather or roosters.
Well, I feel pretty lucky to have all these eggs to eat.
It's so much work.
Thanks, Chooks.
It is best though, if we get our eggs from healthy chickens with plenty of space and sunlight for them to run around in.
And we can use them to make lots of yummy things too, like pancakes.
Oh, omelettes are pretty tasty.
And biscuits. cupcakes, ice cream, custard and cookies.
Delicious.
Oh, you're making me hungry.
Let's get back to the farm.
Maybe we can find some eggs to eat.
Kate, if the eggs we get from the supermarket won't ever grow into a new chicken, how do you get more chickens?
Ah, well, that's where you need this guy.
A rooster is a male chicken and he thinks he's hot stuff.
If the chicken and the rooster mate, then the egg can be fertilised and grow into a baby chicken.
It comes from its mother and dada.
So the eggs at the shops come from just the mummy.
Exactly.
Come on, let's see if we can find any eggs over here.
What's that chicken doing?
The mummy is keeping it warm in the egg because there's not any heat in there.
Yeah, she's incubating her eggs.
That means that for about 21 days after she lays a fertilised egg, the mother chicken keeps them nice and warm by sitting on them very gently.
What happens after 21 days?
Um, I think they just peck their way out.
And peck until the egg breaks.
Hang on, I can see something.
It's hatching.
Peck, peck, peck.
Peck, peck, peck.
It's so cute.
Wow.
A little bit slimy.
It must be pretty special to be born this way, hatched out of an egg.
Actually, most animals on land and in the sea are hatched from an egg.
Really?
Yeah, all birds hatch from eggs, most lizards and fish too, and almost all insects.
Wow, that's like all the animals.
You know dinosaurs come from eggs too?
Aha!
So eggs came first because dinosaurs came way before birds.
Yes, they were eggs long before there were any birds at all.
Cool.
Thanks so much for teaching us about chickens and eggs, Kate.
My pleasure.
It was egg-streamly egg-ucational.
So Pippa, William and Liam female chickens lay eggs by first making a big yellow yolk that's full of fat and protein that travels inside them down the oviduct where layers of gooey egg white are added around the yolk.
To protect it.
The eggshell is sprayed on in lots of layers.
Lobs of calcium.
To become a hard, protective shell.
Careful, don't break it.
The egg is then laid.
And if it's fertilised, the chicken will sit on it for three weeks.
While the baby chick grows.
And then... It hatches.
Chickens are descended from the jungle fowl bird in Asia, but humans have bred them to be very different today.
Most of the chickens in the world now lay unfertilised eggs, the eggs we buy at the shops.
So there's no baby chicks.
But they make them in exactly the same way.
The yolk.
Then the egg tube.
The egg white.
Then the shell.
That's because humans have bred chickens especially for their eggs.
So you can eat them.
A lot goes into making an egg.
So it's important to look after our chooks to make sure they're happy and healthy.
You too, buddy.
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