Hi everyone, and welcome back to Curious By Nature!
My name is Janelle and today we’re going to be talking about one of my favorite insects,
monarch butterflies!
Now you’ve probably heard of the monarch migration, but where are the monarchs migrating
to?
And how do scientists know where they end up?
We’re going to be joined by Dr Doug Taron, one of our insect experts, to learn all about
monarch migration, monarch tagging, and more.
If you’re ready, we’re ready!
Let’s get started!
Today, we are going to be learning about monarchs
and tagging monarchs to help scientists track their migration.
So, the butterfly we're working with today is the monarch
and the monarch is one of the most familiar butterflies,
not only in North America, but in the entire world.
This is really an iconic butterfly species.
When most people think of the butterfly, they think of the monarch,
and monarchs are a very common species here in the Chicago area.
We are right in the heart of their summer breeding range here
and so between the end of May and right about now,
every summer there are three to four generations of the monarch that are found here in Illinois.
So one of the really cool things about monarchs is that they migrate every year.
It's almost more like a bird than a butterfly in that respect.
The monarchs are going to spend the entire winter in the mountains of Mexico nesting
in fir trees.
These are the same monarch butterflies that left Chicago at about this time of year.
So they will leave here, they will get to Mexico in early November, they will roost
in the trees the entire winter and then in March they're going to begin flying northward.
As they fly north, when they get to South Texas, that's the first part of their journey
north where they will encounter milkweeds again.
The female monarchs will lay eggs all over those milkweeds and then die.
And it's actually the next generations that are the ones that will return here to Chicago,
arriving here in late May.
Monarchs that emerge from their chrysalises
anywhere between the middle of August and the middle of September
are the migratory generation and they are going to fly south
from here in the Midwest all the way to the Transvolcanic Mountains in Central Mexico,
about a hundred miles west of Mexico City.
And this is an amazing journey
and one of the ways that scientists have learned that the same butterflies
travel all the way from Southern Canada, all the way from here in the Chicago area,
down to Central Mexico, is that they tag them.
They put little stickers on the butterfly's wings
and butterflies that have been tagged here in Chicago or even further north,
that same butterfly has been recovered down in Mexico.
So that's what we're going to be doing today,
we're going to be putting some of these tags on monarch butterfly wings
and letting them go and continue on their migration to Mexico.
So what we've got is some little tags, they're sticky tags that are
about the size of a paper punch, and a data sheet.
And the tags all have a number on them and the number is going to allow us to track
where and when the monarch was tagged and then, with luck,
somebody somewhere along its migration route will recover it and find one of our tags.
So the information that I have to fill out on the data sheet here
is the number on the tag, today's date, whether the monarchs are wild caught or reared at
home,
whether the monarch is a male or a female, and where we are doing the tagging.
So all of the monarchs that we are going to tag today we've gotten here
on the grounds at the Nature Museum, so they're all wild caught.
And one of the other things I'm going to have to say is whether the monarch is male
or female.
So the first butterfly that we've got here is a male monarch,
and the reason you can tell it's a male is that if you look right on the wing right there
you'll see a little thickening in the vein and the males have that and the females don't.
And so we know that this one is a male,
and so what I'm going to write down on my sheet here is the number on my first tag,
today's date, I will fill in that it's a male,
that we are letting it go in Chicago.
And I am taking the sticker and I'm just gently putting it into about the middle of the wing
and then I just press gently with my thumb and forefinger
to affix the sticker in place and now we have a tagged monarch.
So now that he's tagged we're going to send him back on his way to Mexico.
So bon voyage!
Okay so this time we have a female monarch
and what you can see here is where the male had a little thickening in the vein,
the female the vein is just straight and there's no little spot sticking on the vein there.
Okay so now we have our female, we're gonna again write the tag number down here and today's
date.
We will mark her as a female monarch.
Again wild caught and in Chicago.
Tag onto the wing, press lightly, and say goodbye.
So when people recover the tags,
most of the tags get recovered in the winter time when the monarchs are down in Mexico
and, in addition to doing tag recovery, scientists in Mexico also every year take a survey
of how big the monarch population roosting in the mountains is.
And, unfortunately, over the past couple of decades
the monarch populations in Mexico have been declining
and so people have been concerned about this from a conservation standpoint.
So it's important to know about the migration and about the wintering
so that we can ensure the monarch continues to be a part of the landscape here in the
Midwest every summer.
That’s our show for today!
Thank you so much for joining us.
If you have questions about monarchs, be sure to drop them in the comments below so Dr.
Doug can answer them!
If you’d like to learn more about the work that Dr. Doug and our other insect experts
do with monarchs, be sure to visit naturemuseum.org/monarchs to learn more.
If you’re interested in learning about more local species, like swallowtails, be sure
to check out these videos.
If you enjoyed today’s episode, please be sure to leave a like and subscribe so you
don’t miss a future episode.
We’ll see you back here next time on Curious By Nature!