Hello everyone and welcome Junior Rangers. My name is Ranger Liz and I work for the St. Croix National Scenic Riverway.
Today we're gonna be talking about one of the most successful predators we have on the riverway:
the dragonfly.
Over millions of years, dragonflies have evolved to become very successful hunters
and they have evolved every part of their body to do it.
Today, we are going to make a
dragonfly puppet.
To help us out, to learn the different parts of the body of a dragonfly.
To make our dragonfly puppet, you'll need a few supplies.
First, you'll need two pipe cleaners; one that's colorful, and one that's a dark color.
You will also need to have a pair of scissors,
beads, you'll need two of them for this project,
and you also need a pen or pencil and a piece of paper.
Dragonflies, like all insects have three distinct body regions, which are
their head,
their thorax, and their abdomen.
First we're going to talk about their head, which is dominated by one specific feature:
their eyes.
Now, their eyes are so big it allows dragonflies an almost 360-degree
view of the world. There is only one blind spot on a dragonfly and that's really right on the back of the head.
Dragonfly eyes are what are called, "compound eyes".
Compared to human eyes, which are, "simple eyes".
The difference between those is how many ways that light can enter the eyes.
Compound eyes are comprised of many different lenses letting in sunlight.
Simple eyes, there's really one way to do it. So human eyes only have one lens letting in light
Dragonflies on the other hand have
24,000 different lenses, per eye, letting in light.
Dragonfly eyes are all so amazing, that they can see a wide array of colors.
Now, human eyes have three base colors that they can see which are red, blue, and green.
Now dragonflies on the other hand, can see twelve base colors, and that's including UV light and
polarized light.
Dragonfly nervous systems,
coupled with their eyesight, make them really really successful hunters.
Because, they can one,
single out one
individual from a swarm
and follow that one individual, and they can predict the trajectory of
that individual. They could predict it and then be there and catch that
fly or bee or whatever. They're very very successful in their hunting.
First we're going to start with making the head of the dragonfly.
You're going to take your colorful
pipe cleaner and two beads. I went with green glitter because the glitter looks like
the lenses of a dragonfly eye.
You're going to thread your beads
to the center of your pipe cleaner.
And you fold in half
like so.
And then to make the head, you're gonna twist one or two times right behind the eyes
to make the head.
Next we're gonna talk about the thorax, which is the body region in all
insects that the wings and the legs are attached to. All insects have four wings and
six legs.
Dragonflies have very sophisticated
muscles that are attached to their wings
that allow each wing to act independently.
So that means that one wing could be moving around in circles,
and another wing can be flat. This allows the dragonfly to move in many different directions.
Forwards, backwards,
side-to-side,
upside-down, and even hover in place just like a hummingbird can do.
Now, our dragonfly wings,
as seen by our
American Emerald, which is a dragonfly that is common on the upper part of the
St. Croix Riverway, you can see that are comprised of
many different veins
on very broad wings.
You can see in the middle part of the
wing is an area that is darker. Now, this is where the veins cross.
This part is called the "nodus".
The nodus is an area where there it's just a little bit more
flexibility in the wing. If you look at the tip of the wing, you'll see another dark spot.
This part is called the stigma. The stigma acts as a counterweight.
There's a lot of vibration that goes on in the dragonfly body when it flies.
If the stigma wasn't there, it would basically vibrate itself to death.
So, as a counterweight gives the dragonfly a very comfortable ride.
Now dragonflies can fly really, really, fast.
Large species has been documented
at 35 miles-an-hour as their top speed. On average though, a dragonfly is about ten miles-an-hour.
They also can accelerate
extremely fast. Now, on the G scale,
a dragonfly, when they are accelerating,
can reach four G's.
Now that doesn't mean very much but let's go this into human terms.
When humans are blasted off into space in a rocket or shuttle, they also
reach four G's.
A rocket versus a dragonfly just accelerating.
That's amazing! That these little creatures can reach that amount of G's. And that's just when they
are accelerating when they are trying to catch their prey and they're maneuvering
tight corners, they can reach
nine G's. Now, nine G's for a human
is very very uncomfortable and some humans might even pass out.
And once again, this is for a creature that is
four inches long. Now, our dragonfly wings
are about that same ratio as well. But can you imagine
back 300 million years ago,
325 million years ago to be exact,
our dragonflies were even bigger. They had a wingspan of about two and a half feet
Can you imagine a dragonfly that has a
two-and-a-half feet wingspan compared to our
little dragonfly that has our four inch wingspan?
Just imagine that flying around!
First, we're going to start with making our wings. Now, there are a couple different ways that you can make your wings.
you can go online and there are templates that you can go and print them out yourself
or, you can draw them, like we're gonna do today.
So see that there are four wings and they are relatively broad, with the bottom wings
slightly broader than the top wings.
You can also see that they have the tips of their wings are more up
in a smiley-face configuration
compared to a
frowny-face configuration.
So let's start!
Next, to cut them out.
Next, we're going to draw the veins on the wing.
So remember our different parts of our wing. We are going to have the cross point, the nodus,
right on the top wing in the middle of it.
We can't forget our stigma,
which is that black counterweight on the tip of the wing.
And then, we start drawing the rest of the veins.
To attach our wings to your dragonfly
you're gonna make some scissors out of your body there, one on top one on bottom
and you're going to slide
your wings behind the head.
Next, we're gonna talk about
dragonfly legs, which are also connected to the thorax body region.
You can see in our picture that the legs are in a curl position
with their hooks at the bottom for their toes.
Now, dragonfly legs aren't specifically designed for crawling. They rarely
crawl. They are more designed for perching and catching their prey on the wing.
So you can see, the way that this
dragonfly is pictured is that their legs are in a
basket sort of shape.
So when they are hunting they fly around and
they catch their prey in the basket, which then they bring up to their mouth and
eat their prey.
Next, are the legs. So you're gonna take your dark-colored pipe cleaner. You're gonna cut it in half.
We need half of it. What you're gonna do is you're going to put the black pipe cleaner
underneath
your wings
between the wings and the back of the pipe cleaner.
Put that to the middle.
To secure the wings and the legs,
you are going to twist the pipe cleaner, the body pipe cleaner,
right behind the wings
and to finish off the legs,
remember they perch, they don't crawl. So this is gonna be a finger puppet
You're gonna make a ring
and fold the ends in so you don't poke yourself.
And you've made your legs!
The last body region that insects have is their abdomen. In dragonflies,
there are many different shapes that the abdomen can come in. Let's go back to our American Emerald.
You can see that this species has a very long and very
slender abdomen.
Now the exact opposite to that is going to be at the Common White-tail.
The Common White-tail has a very short and very thin
abdomen. This is a characteristic of a lot of skimmers.
Another very distinct sort of abdomen can be shown in the Club-tail family.
Our Middlin Club-Tail that you can see has a very thin
abdomen until you get to the tip, where it swells too make a club.
Researchers use these kind of characteristics to help them identify
and narrow down what they are looking at.
Now it's time to finish up your dragonfly puppet,
by finishing it up its abdomen.
So remember our different kinds of abdomens we have. You can twist
the ends of your pipe cleaner
to make it long and skinny like our Emerald.
You can fold
the end of it
to make a bulb,
like our Club-tails
or you can
cut off some of your dragonfly,
untwist it a little,
fan it out, make it thin, and you've made a skimmer!
So after you do that your dragonfly is done!
Through time,
dragonflies have adapted every part of their body
to become one of the most efficient hunters on the planet
with a 95% success rate. That means that they can hunt
30 to 200 mosquitoes per day.
And for us humans, that means a whole awful lot, doesn't it?
Dragonflies here on the
St. Croix National Scenic Riverway are very significant creatures for the fact that we have a very special
dragonfly all to our own.
In 1993 a dragonfly was discovered on the upper St. Croix River and it was
aptly named, the St. Croix Snake Tail.
It's so amazing that dragonflies and creatures are still being discovered today!
And it's so significant that this dragonfly really can only be found here on the
St. Croix River. So through all of this time,
they have been adapting their bodies and become one of the most
masterful hunters on the planet.