Thanks to Brilliant for supporting this SciShow List Show!
As a SciShow viewer, you can keep building your STEM skills
for 20% off an annual premium subscription at Brilliant.org/SciShow.
[ intro ]
If you wasted some time in the 80s playing Frogger,
you might have been left with the impression that frogs just aren't that tough.
After all, if falling off a log can be fatal
there would seem to be little hope for survival
outside the ponds and streams they’re often associated with.
But real frogs, not computer game ones,
have been around for 250 million years,
and they have adapted to survive almost everywhere on the planet.
Here are just a few of the wildest places that frogs live,
all of which take a lot more fortitude than little Frogger ever had.
Northern leopard frogs can be found throughout North America,
from parts of Canada all the way to New Mexico.
You might have surmised that the northern reaches of that range have much colder winters
than those in the south.
So how do the northern-most of the northern leopard frogs survive that cold?
Well back in 1972,
scientists discovered some leopard frogs overwintering in a frozen pond
about 50 km north of Toronto in Ontario, Canada.
To survive the cold, the frogs were hibernating under the ice.
But because hibernating frogs are easy prey for predators,
the frogs also needed a safe place to wait out the season.
They were hibernating in what researchers called hibernation pits.
The frogs covered the pits — and themselves — with silt.
That helped camouflage them from predators like trout,
which remain active during the winter.
But there’s still one problem that these frogs had to solve:
Getting oxygen at the bottom of a lake.
You see, frogs have two ways they can absorb oxygen.
They have lungs and breathe oxygen like we do,
but they also get oxygen through epidermal breathing,
or the ability to take in oxygen through the skin.
Since frogs can’t use their lungs underwater,
these leopard frogs definitely have to go with option B here.
But because there’s not enough oxygen available under the layers of silt,
it means they need to leave a gap in the protective layer to let fresh,
oxygen rich water back in.
They also maintain some slow movement throughout the cold season,
to help flush out some of the silt so they can get needed oxygen.
All that means they can remain cozy and mostly hidden throughout the winter.
Probably not especially warm, though.
Now it’s a fact of life that every living thing needs water to survive.
But frogs don’t just need to drink water.
Their skin needs to stay moist, too, which is why they often live near water sources like ponds.
However, there are some frogs that can survive in dry places
where there is no ground water visible at all.
Take for example, the desert rain frog.
It lives in South Africa and kind of looks like Grumpy Cat
if you stuffed her in a hamster ball.
As its name implies, desert rain frogs are found in the desert.
But the word “rain” isn’t exactly accurate.
These frogs’ main source of water is not rain.
On average, their habitat only gets between 100 and 200 mm of rain in a year,
most of it in the winter.
So the desert rain frog has to figure out how to get water in other ways.
But these frogs don’t live just anywhere in the desert.
They opt for deserts near the shores of the Atlantic Ocean.
They’re also most active at night,
when there’s more likely to be marine fog rolling off the sea.
That fog keeps the frogs and the sand damp, at least for a little while.
Then during the day, the frogs burrow into the fog-dampened sand,
which retains moisture and keeps their skin from drying out.
No pond necessary!
Next, Nearly 9,000 feet above sea level,
on mountain tops so forbidding
that researchers have a hard time even reaching them,
the saddleback toad is on cloud nine.
Saddleback toads are a group of tiny frogs,
typically less than 1.5 cm from nose to butt.
Now these toads don’t actually float around in the clouds or anything
though that would be pretty cool.
They live in leaf litter on the forest floor.
It’s the forests themselves that are in the clouds.
Appropriately, these are called cloud forests,
which are lush environments that grow at such high elevations
that their canopies regularly touch the clouds.
Saddleback toads are so optimized to live in these cloud forest
s that they are basically the only places they can live.
They’re adapted to the exact set of conditions found there.
Specifically, they need a cold, humid environment.
And because you’ll mostly only find that on mountaintops,
saddleback toads exist only in small, isolated populations.
They can’t really reach their neighboring toad groups since
that would require leaving their comfort zones.
This makes these toads especially vulnerable,
since they basically live on mountaintop islands.
In fact, many of the species of saddleback toads seem to be restricted
to just one or two mountaintops, meaning they are microendemic.
Species that are microendemic
are often more vulnerable to changes in their environments,
which means saddleback toads have a lot to worry about.
That said, these places are extremely remote and hard to access,
what with being at high-elevation mountaintops.
They’re so remote that scientists struggle to even get there to study the wildlife,
so there’s a lot we have to learn about saddleback toads. .
Now, all the frogs we’ve talked about need to spend at least some time in the water.
But none of them are full-time water dwellers.
And as it turns out, evolving to live in water all the time requires some adaptations
that bear an awkward resemblance to a certain feature of human anatomy.
The tongue? Is it the tongue? Is it ears?
The scrotum frog lives in Lake Titicaca,
a high altitude lake in the Andes mountains,
as well as a few neighboring lakes.
But it turns out there’s an evolutionary reason for this scrotum frog to look …
like it looks.
Specifically, these frogs are well suited to their underwater lifestyle,
all thanks to their somewhat awkward appearance.
We talked about how frogs absorb oxygen through their skin while underwater.
The more surface area of skin a frog has,
the better they can absorb that tasty oxygen,
which is why the scrotum frog’s loose, flappy skin is such a useful, if not great looking, trait.
The skin flaps are an adaptation to the lower oxygen environment
where these frogs live.
The scrotum frog is huge,
and its large size gives it more surface area to absorb oxygen, too.
It also has the slowest metabolism of any known frog,
which means it doesn’t need as much oxygen to begin with.
All this helps them survive in the hypoxic,
Or oxygen low waters they are found in
And when it needs a little extra oxygen,
it does a dance-like bobbing thing, which helps get more of it into the skin.
Scrotum frogs are so good at surviving in these low-oxygen waters
that they’re fully aquatic.
They don’t ever come to the surface, because there’s no reason to.
Which is probably a good thing, I don’t know that I would want to see one
Most of these frogs share their environments with at least some other creatures,
albeit ones that make a little more sense to be found there.
But our final frog has managed to survive in an environment so barren
that it’s been deemed a “wasteland.”
The thumbnail-sized laterite frog is found along the West Coast of India.
The region is usually rocky and devoid of life.
But during the monsoon season, pools will form on the surface.
And some things manage to live in and around the pools, including plants…
and amazingly, these frogs.
So where do these frogs go when their pools dry up?
Well, your guess is probably about as good as anyone else’s!
Scientists only began researching the laterite frogs in 2016,
and haven’t made much progress.
Given how little we know about them,
you’d think that we’d all be making sure to protect their home turf
and study this entire ecosystem hiding within a wasteland.
But unfortunately the habitat isn’t protected, and local people use the area to dump trash,
wash their cars, and just generally create hard-to-clean up messes.
It’s also full of a mineral called laterite that can be used to make bricks,
so there’s lots of mining activity in the area too.
Because the frogs live in small, seasonal pools surrounded by barren rock,
their habitat is already pretty fragmented.
And the lack of protection makes them even more vulnerable.
Still, their existence —
and the fact that they’ve only been known to science for a few years —
challenges the notion that anywhere can truly be described as a “wasteland.”
With the right acquired traits,
even a place like this can be a comfortable home for someone.
From frozen ponds in Ontario to a trash dump in India,
frogs can live in a lot of unlikely places,
and they owe their resilience to millions of years of adaptation.
It just goes to show that there’s almost no problem that evolution can’t solve.
Even if it does have to make something look like a scrotum to do it.
Thanks for watching this SciShow video
and thanks to Brilliant for supporting it!
Brilliant is an online learning platform with courses in
science, computer science, and math.
So to learn more about how their looks help frogs adapt to different environments,
you can take the Brilliant course: Geometry Fundamentals.
This interactive course covers surface area to give you a better idea
of what skin flaps could do for oxygen absorption.
And while the frogs we covered in this video
might not be the examples provided in the course,
Brilliant weaves in many other examples throughout the 25 lessons
so you don’t have to learn in the abstract.
You can check it out by clicking the link in the description down below
or going to Brilliant.org/SciShow
for 20% off an annual premium Brilliant subscription.
[ OUTRO ]