[♪ INTRO] Here at SciShow, we love snakes. We’ve got episodes on venomous snakes, and
poisonous snakes, and we’ve even had some on SciShow as Talk
Show guests. But you might still think all snakes are basically
the same. You know, like, they’re all just, like,
this slender, muscular danger noodle. So in this episode, we want to pay special
tribute to the incredible diversity of these legless
creatures. We’re going to talk about 6 snakes with
some extraordinary features. Hognose snakes get their affectionate name
from their enlarged rostral scale, which is the plate at the front of a snake’s
nose. That gives them their upturned noses which
make them look, you know, kind of cutely pig-ish. And kinda like a pig’s snout, their little
snoots are great for rooting around in the soil. The upturned nose acts as a shovel to move soil
or sand out of the way as they make a safe burrow. The snakes will bend their heads downwards
and then wiggle them from side to side. At the same time, their bodies move in wave-like
motions to help them sink below the dirt. Those piggish noses also help them find food. They eat everything from lizards to small
mammals, but a nose for digging helps them most if they’re looking for frogs
and toads that spend part of the year underground. Their fangs, which, like other rear-fanged
snakes, are located further back in their jaws than
front-fanged snakes, are long and smooth, so some scientists thought that they might
be used for popping toads that inflate themselves as a defense mechanism. But a scientist back in 1976 measured how
long the fangs would need to be, 1.38 cm on average, in case you were wondering, which is much longer than the fangs actually
are. They’re only about 0.3 - 0.5 cm. The hognoses’s unique hiding and hunting
behavior is pretty cool, but they have another trick up their scaly
sleeves. When they feel threatened, they’ll roll over on their
backs and play dead, also called death feigning. And hognoses really get into this dramatic
act. They will writhe around and stick out their
tongues until whatever scared them is gone. Way back in 1974 scientists noticed the snakes’
heart rate would also drop while death feigning from around 50 to 80 beats per minute to between
3 and 15 beats. That is some dedication as a method actor! Stiletto snakes might sound fashionable but
that name isn’t because they have good taste in high-heels. They are a burrowing group of snakes found
mostly in sub-Saharan Africa. There, they inhabit everything from deserts
to rainforests. And they’re best known for their long, knife-like
fangs that allow them to stab prey without opening their mouths. Most snakes strike when their potential meal
is right in front of them—but not stiletto snakes. They’ll slide up past an unsuspecting skink,
lizard, gecko or mouse and then whip their head backwards to lodge
one of those long fangs in the prey. It’s such a unique movement done at close
range that some scientists prefer calling it “fang
stabbing” rather than striking. And it might sound like a weird way to hunt,
but it’s actually really useful as it lets the snakes capture prey in tight
spaces like tunnels or burrows. It also allows them to release the prey really
quickly, because they don’t have their whole mouth
wrapped around it. And that’s important because some of the
stiletto snakes’ prey, like scaly lizards, tend to fight back. So they want to get in, deliver some venom, and then back off until the toxins have done
their job. In fact, the snake’s entire mouth is specifically
adapted for this weird attack. Stiletto snakes have a short jaw bone, fewer
teeth, and a snout that’s tightly attached to the
rest of the skull so the jaw stays clamped closed when it’s
wiggling through tight spaces. But this awesome ability and anatomy has its
downsides. Stilettos lack the teeth needed to do the
usual pterygoid walk to swallow their prey. That’s where a snake will open its mouth
and use specific teeth to hook and then pull prey into its mouth step by
step. Which makes sense if you don’t have, like,
hands to shovel food in your mouth, like, awww, I do. And even if they had those teeth, their jaws
don’t open wide enough to swallow food that way. So stilettos have to do a weird head wiggling
action where they shift their jaw backwards, flex their head down toward their belly and
squeeze their trunk forward, then shift their jaw and head forwards over
their prey. It sounds pretty awkward if you ask me. And according to scientists this is pretty
much as extreme as this adaptation can get. Basically it can’t really improve upon its
unique strike without sacrificing the ability to eat. The Pseudocerastes snakes of the Middle East
range from southern Israel, through Iraq, southwestern Iran and Afghanistan
and Pakistan. They get their scientific name from the false
horns on the top of their heads, but it’s what’s on the other end of the
snake that’s more interesting. You see, vipers are ambush predators. They select a good hiding place and then wait
for prey to come by. Even with the perfect location, though, it
can take a bit of time for the right meal to get close enough, so these vipers wag their
tails around as a lure to draw their prey in. And one of these snakes, the Iranian spider-tailed
viper, has arguably the most elaborate tail lure
of all. Most of its grayish brown body blends in almost
perfectly with the gypsum rocks common to its habitat. But its tail looks just like a spider, and
with some careful jiggling back and forth, it would probably have you fooled too. But don’t worry, it’s birds that this
spider is after. The good news is that I, personally, am not
ever attracted to a spider on the ground, so I’m probably not gonna get lured in by
this. But birds do have to be worried. These snakes seem to mainly hunt larks, shrikes
and warblers, but have also been known to catch the odd
gecko, too; basically anything that goes for that tempting
tail. But, there are some issues with a lure that
is so convincing. Researchers have found snakes with damaged
tails, presumably because some birds actually bit
the “spider”. It’s unclear whether this makes the snakes
any worse at luring in prey. But I bet it doesn’t feel too great to have
part of your tail bitten off! Hunting underwater comes with an entirely
different set of challenges than the snakes that we’ve talked about
so far. Like for example, finding your prey when the
water is slow moving or not very clear, or striking with enough power to counteract
the resistance of the water. But the tentacled snake seems to make light
work of it. This species can be found in slow moving rivers
and murky ponds in southeast Asia, where it feasts almost exclusively on fish. The snake will sit motionless in the water
in a kind of J shape and wait for fish to approach. It will then move sections of its body to
herd the fish up towards its jaws. When the fish is positioned in a little crook
between the snake’s head and body, the snake will whip its head sideways to strike, turning its head to meet the fish front on
at the last moment. This is different than most other snakes,
which coil up their bodies and strike forwards. The tentacled snake will even preempt the
fish’s escape. It strikes where the fish will be, not where
it currently is. Though scientists aren’t yet clear whether
it’s back and forth evolution between predator and prey or individual experience
that led to such smart targeting. The snakes possess some awesome features that
facilitate this unique attack. Probably the most distinguishing one is those
little tentacles that jut out from the sides of the snake’s
nose. They are highly sensitive to changes in water
around them. They’re stuffed full of nerves that send
signals to the snake’s brain when anything within a two centimeter radius
of them moves. That’s exactly how close a fish is when
the snake would want to strike. The snake’s shallow, flattened skull is
thought to help it hunt underwater because it minimizes drag as the snake strikes, allowing it to attack with the same, or even
more force, as land snakes. That’s pretty remarkable considering it’s
pushing against water instead of air. It also helps that the snake can engulf the
water ahead of it when it strikes instead of pushing it out
of the way. Now, you may tremble at the idea of any snake
slithering towards you, but what if the snake was, like, flying through
the air? So-called flying snakes of the genus Chrysopelea
are sometimes called the only limbless vertebrate flyers. But flying is a misnomer. They’re actually gliding. I’m not any less scared of them. These tropical southeast Asian snakes will
launch themselves off a high perch, slither through the air to land some 8 to
16 meters away. That’s pretty impressive given the snakes are only
around half a meter to just over a meter in length. In the mid 2000s, scientists filmed the paradise
tree snake species as they launched themselves from a platform,
and then reconstructed those jumps in three dimensions, to figure out exactly
how the snakes were moving. Let’s start with takeoff, which is kind
of a hard thing to do without legs to push with! So, the snakes make a J shape with the front
part of their bodies while hanging from their tails, and launch
themselves that way. They then enter a falling phase for a short
while before leveling out and gliding, all the while undulating their bodies in a
complex side to side pattern. They can even turn in midair!
Talk about falling with style! And this movement is pretty different from
what snakes do on the ground so scientists think that this special wiggling
might help them generate lift or stabilize them while gliding
somehow. Some of their ability to glide also comes
from the way the snakes flatten their bodies horizontally
once they’re in the air. The flattening functionally turns their bodies
into a wing, which separates the air in front of it into
two streams: one above the body and one below. The difference in pressure between the air
that goes under the snake and over the snake can generate lift, just
like an airplane wing! But scientists aren’t 100% sure why these
snakes “fly”. It’s not more energy-efficient than wiggling
along the ground, but it is quick so it might help them escape
predators better. Either way, if you see one of these snakes
slithering towards the end of a branch, I would move out of the way. The olive sea snake spends its time swimming
around the coral reefs of Northern Australia, Papua New Guinea, and New Caledonia using
its paddle-like tail to propel itself through the water. Its long, skinny body lets it squeeze into
crevices in search of crabs, prawns, fish eggs and fish. But it’s not the only hunter in these waters,
so it often ducks into those same crevices to hide. In fact, aside from surfacing for air, courting
a mate and, of course, nabbing some food, they usually spend their time trying to fit
as much of their 1.2 meter long body in coral as they can. There’s only one problem with that. If the snakes’ tail peeks out, it risks
getting chomped on. So the olive sea snake has evolved a really
neat way of keeping an eye on its tail. Literally. The skin on its tail can sense light, which means the snake can adjust if it “sees”
its tail sticking out. Scientists first studied this ability in the
late 1980s when they kept ten snakes in a darkened lab
tank. They noticed that the snakes pulled their
tails in when researchers shined a fiber optic light
on them. This phototactic response only worked when
the light shone on the tip of the tail not the part closer to the rest of the body. Then, in a study published in 2019, researchers looked to see if other sea snakes
also had this ability. They found that two other species of sea snake
showed a similar response to light, and since they were close relatives of the
olive sea snake, the researchers concluded that this ability
probably evolved in their common ancestor. That may mean that 10% of all sea snakes sense
light with their tails! By using RNA sequencing, the scientists figured
out that their tail skin expresses genes which code for a light sensitive
protein called melanopsin and also other proteins involved in how light
receptors sense light levels, which might explain how they actually “see”
with it. So you see, snakes aren’t just muscle-y
danger noodles. Whether it’s being a really talented actor,
gliding between trees or having a tail that looks like a spider,
snakes are super diverse. And hopefully, understanding these animals
and their weird, unique adaptations will help us all appreciate
them a little more. Thanks for watching this episode of SciShow! We put out educational science videos like
this every day, so be sure to click that subscribe button
to get them all into your feed. And if you liked learning about these awesome
snakes, you’ll probably love our episode on 7 uniquely
fierce sharks! I mean, I’m not, like, telling you what
to do or anything, but if it were me, I’d watch that one next. [♪ OUTRO]
