There's a lot of different kinds of
iguanas that live in the Galapagos
Islands. The one that's probably most
famous is the marine iguana, since it's
the only place anywhere in the world
where iguanas have basically adapted to
a marine lifestyle. They're able to be
underwater for 25 minutes, and they
primarily feed on algae that's
underwater, so they hang out by the shore,
and they dive into the water, and they
chew on some algae, and then they come back
up. But there's also some land iguanas
like the one you see right behind me.
This fellow has a even lazier lifestyle, actually much lazier than the marine iguana,
since it doesn't have the courage to get
into the water. It basically sits
underneath these cactus trees that you
see around here, like those in the
background, and these cactus trees are
pretty old. Some of them are as old as
100 years. Basically they grow a trunk as
they start to drop some of their paddles,
and they get a little bit taller. When
those paddles fall on the ground and the
only thing left behind is that stumpy
trunk, these guys will gobble up the
cactuses that fall. They're not actually
strong enough to climb on the trees. They
don't have the claws to do that so
they just have to wait until they get a
meal. And the nice thing is those
cactuses are really well adapted
to storing a lot of waters, so that's also
that they get their hydration and so
they're able to survive in a desert
environment like this. There's some other
iguanas that live on land that can
climb the cactuses, but these guys are
not able to, so they're able to get
through the spines with their thick skin,
but then they just kind of have to wait.
And if a meal doesn't come then they
just bask in the Sun until it does. They
can live for a very long time because
they use so little energy, and they're
cold-blooded so they don't use as much
energy to regulate their heat, so they
spend most of their time just chilling,
basking in the Sun like this with very
few predators have to worry about.
It's kind of hard to see them because of
the camouflage that they're using. These
iguanas behind me are unique in the
world. They're called marine iguanas, and the reason
they're called marine iguanas is because
they basically washed up on shore
here once a long time ago on these
islands, and they're land animals that
only eat plants and have nothing really that they can do to get back to wherever they
came from. So they had to figure out how
to adapt to survive or just to die. Some
of them died, some of them happened to be able to be daring enough and agile
enough that they can swim, and then get
some food in the water. Some of them also
happen to have big enough lips that they
could handle the surf and still be able
to eat some of the food there. Some of
them have glands that would allow them
to shoot out some of the saltwater that
came with all their food. By and large,
all the traits that happen to be best
for these species to survive were the
ones that helped the ones who could
survive pass on their traits to the next
generation when they reproduce. The ones who didn't have those traits, those those
animals died and so these animals
evolved from being land iguanas to being
marine iguanas.
So right behind me are a bunch of those
marine ones we were looking at earlier. You
really can't find these anywhere else in
the world. Everywhere else, iguanas
are gonna be stuck on land, but once they
got washed up on shore here in the
Galapagos, they really couldn't do
anything but get in the water if they were
going to get any kind of food. They eat a
lot of seaweed, a lot of other small
plants, and unfortunately because they're
in the ocean so much they get a lot of
salt in their diet which isn't good for
them. So they've developed this adaptation
with their glands where they'll actually
sneeze out some of the salt every once
in a while and just kind of shoot it out
through their nose like they're shooting
milk out what somebody laughs. When they do that all the salt comes out and they
can just digest the food, which keeps
them a lot healthier.
