(phone ringing)
- Hi, it's Doug.
It's not every day you
see an animal that's pink.
But recently, when I was
visiting the tide pools
in California, along the ocean,
I spotted this tiny little animal.
Up close, it looks like a pink shaggy dog,
or maybe an alien.
Turns out, it's a type of sea slug
that lives along the Pacific coast.
Someone named Yoxagani has a question
about a slightly more
famous pink animal though.
Let's give Yoxagani a call, now.
(phone ringing)
- Hi, Doug.
- Hi, Yoxagani.
- I have a question for you.
Why are flamingos pink?
- That's a great question.
Birds come in so many different colors,
but it's not every day you
see a bird that's pink.
Why are flamingos pink?
I find it's always interesting to find out
why something is the color it is.
We've explored other
color questions before
for lots of different things.
Like, why is the sky blue?
Why is Mars red?
Why are pumpkins orange?
And if you've seen those episodes,
then you know that there are
sometimes different reasons
why things can be the color they are.
But, in general, a lot of things around us
are the color they are because,
on a microscopic level,
when we look at them close
up under a microscope,
we find out that they contain
tiny amounts of substances
made of that color.
We call these color substances pigments.
Maybe you've heard that term before?
Leaves are a great example of this.
When microscopes were first invented,
we were able to find out that
the reason leaves are green,
is because they're filled with
these tiny microscopic blobs
of a green substance, a green
pigment called chlorophyll.
And it's a similar reason why most animals
have the colors they have,
like this black cat and this
black Labrador retriever.
When scientists look at
their fur under a microscope,
they find it contains
a black-colored pigment called melanin.
This black-colored pigment in their fur
is just something these
animals were born with.
Their whole lives, these animals' bodies
naturally make melanin
and store it in their fur,
which is why they're colored black.
So, you might expect then that
the reason flamingos are pink
is because their bodies
naturally make some kind
of pink-colored substance,
some kind of pink pigment.
Based on why other animals
have the colors they have,
that would make sense.
But have a look at this
baby flamingo, it's cute.
But notice, it's not pink.
And check out even these adult flamingos.
Wait, why are they kind of white?
Are these some rare,
white kind of flamingo?
They're not.
In fact, all flamingos look
kind of light gray or white
each time they molt, or grow new feathers,
to start to replace their old feathers.
The new feathers always
grow in grayish white.
What, what's going on here?
Why is it that in so many
photos and videos you see,
even in flamingos you
might've seen yourself,
like at the zoo, they look pink?
Do flamingos somehow change color?
What do you think?
Now would be a good time to
pause the video and discuss.
Okay, you ready?
Well, our mystery can be solved
by noticing something
zookeepers would have noticed
when they first started
keeping flamingos in zoos.
You see, they had to decide
what to feed the flamingos.
With other water birds,
zookeepers knew it always worked
to feed them specially made pellets,
kind of like bird chow,
and flamingos seemed
to do okay on that too.
But this isn't what
flamingos eat in the wild.
And zookeepers soon
discovered that flamingos,
fed these pellets,
well, once they started
growing new feathers,
their feathers came in
white and stayed white,
as in they lost most of their pink color.
And there didn't seem to be any hope
of them getting it back,
until someone had the idea,
"Wait, could it be there's something
"that wild flamingos are eating,
"which isn't in these
pellets we're feeding
"the flamingos at the zoo?"
There was only one way to find out.
And that was to observe
flamingos in the wild
and find out exactly what they're eating,
then feed the same wild
food to the white flamingos
at the zoo and see what happens.
It turns out flamingos in the
wild, they eat lots of algae.
That's small plant-like organisms
that float in the water,
as well as tiny shrimp
that look like this.
Both the algae and the shrimp
that wild flamingos eat
contain a kind of
orangish-pink colored pigment.
You can actually see this color
really easily in the shrimp.
The pink color in the
algae that flamingos eat
isn't always easy to see.
But there are some types of algae
that are much more obviously pink,
like the algae that lives
in this lake in Australia,
named Lake Hillier,
but known around the world
as Australia's Pink Lake.
Or if you ever fly in and out
of San Francisco, California,
you can notice this algae
growing in some of the ponds
along the edge of San Francisco Bay.
Sure enough, by feeding
things like algae and shrimp
to flamingos in the zoo,
they get their pink color
back and they keep it.
So, in a funny way, flamingos
are like a real life example
of the expression, "You
are, what you eat."
They get their pink color
from the pink pigments
in the foods that they eat.
It might seem really unusual,
but flamingos aren't even the only animals
that get their color from
the foods that they eat.
That sea slug I showed you earlier?
It's pink because of what it eats.
And it's not just with
the color pink either.
Some birds, like Cardinals,
they get their red color from pigments
in seeds and berries that they eat.
But maybe weirdest of all,
it turns out that even human
beings can change color,
depending on the food that we eat.
It's been discovered that
when parents accidentally feed
their babies too much baby food
containing orange-colored
fruits and vegetables,
things like carrots,
squash and sweet potatoes,
a baby's skin can start to
take on an orangish color,
especially their noses.
This tends to be more noticeable in babies
that have otherwise pale skin.
If this happens, at first it can make
any parent feel worried,
"Is my baby okay?"
But doctors don't consider
it a major health problem.
They just suggest that the
parent maybe not feed the baby
quite so many carrots and
sweet potatoes all at once.
So, in summary, while most animals
are born with the colors they have,
flamingos get their famously pink color
from the food that they eat.
That's all for this week's question.
Thanks, Yoxagani, for asking it.
There are mysteries all around us.
Stay curious and see you next week.
