Episode 31: Monarch Mania Transcript


Nature Boost Podcast


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Hey there and welcome back to Nature Boost.  I'm Jill Pritchard with the Missouri Department of Conservation.  Late summer is a wonderful time to learn about the iconic monarch butterfly.  That's because this is when these beneficial insects are migrating through Missouri on their way to wintering grounds in central Mexico.  

I liken monarchs to hummingbirds.  It's a special moment when you see one and you always stop what you are doing to enjoy the sighting.  And both monarchs and hummingbirds make huge migration journeys for such small creatures.  

During their fall migration, monarchs will travel up to 3,000 miles to Mexico, farther than any other butterfly.  No monarch makes the trip more than once.  They only live about a year.  

Did you know that western Missouri serves as one of the critical monarch butterfly migration corridors?  One of their primary migration routes bisects northwest Missouri and is referred to as the I-35 Monarch Migration Corridor.  Unfortunately sightings may be less common as populations of these butterflies have been declining over the years.  So much so that the International Union for Conservation of Nature placed the monarch on the red list of threatened species just last month the IUCN listed the monarch as endangered noting that its primary threats are habitat loss and climate change.   The listing is the first time the monarch has officially been declared at risk of extinction.  

Considering how beloved monarchs are and the threats the species is currently facing dedicating an episode to this popular butterfly seemed more than appropriate and definitely timely.  

These well known insects are distinguished by their relatively large size with a wing span of up to four inches.  Their rusty or orange colored wings with black veins and their black bodies.  You can tell males and females apart by their wing patterns.  The black veins are darker on females, and males have a black spot on each of their hind wings.  

Fun fact.  Their wings consist of scales that overlap like roof shingles.  The scales help them with flying, increase their heat retention, and give them their eye-catching color pattern.  The monarch was named in honor of England's King William the Third also known as the Prince of Orange.  


Like all species of moths and butterflies, monarchs undergo complete metamorphosis.  This means they go through four stages of their life cycle.  Egg, caterpillar, pupa, and adults.  The four stages take only about 30 days to develop from egg to butterfly.  Females lay around 400 eggs on their vital host plant the milkweed and tiny caterpillars soon hatch.  Milkweeds are crucial for monarchs because it is the only plant that caterpillars will eat.  And boy do they eat, and grow, and eat and grow!  Monarch caterpillars undergo five molts where they shed their skin and emerge a little bit bigger each time.  

Each stage between molts is called an instar.  During this period, they can grow up to 2,000 times larger than their original size.  

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After reaching the final instar, the caterpillar enters the pupa stage and will find a secure location where it can hang upside and form a chrysalis in which its tissues are transformed and it becomes a butterfly.  Once it emerges from its chrysalis the monarch will spend a few hours drying its new wings and pumping them full of fluids to make them expand.  On niece done, it begins the hunt for nectar.  

The monarch caterpillar and the butterfly both have striking appearances.  The caterpillars are white with black and yellow bands and of course the butterflies are known for their orange and black design.  But the color pattern of both larvae and adults mean something different to their fellow wildlife.  Their bright colors serve as a warning to predators that they are toxic.  

Remember the milkweed the caterpillars eat?  It is full of chemicals I can't pronounce and that means the caterpillars are deadly to eat.  These toxins remain even after metamorphosis, making the adult monarchs poisonous too, even though they no longer feed on milkweed plants.  And different milkweed species vary in toxicity so some monarchs are more poisonous than others.  

Broods of monarchs are produced in Missouri in summer and fall.  These newly emerged butterflies will then make their long journey south usually in September.  They'll land in high elevation Oyamel Fir forests in central Mexico.  Once there, they will gather in massive numbers in their roosting trees.  Can you imagine witnessing such an event?  The tree suddenly looks like thousands of orange flowers have blossomed.  


The clusters of monarchs can be so dense they've been known to break tree branches.  In the spring, around March, the monarchs flutter back north.  Females will lay eggs around the way across the southern part of the states and then die.  Their offspring live two to six weeks, and each generation flies farther north.  Butterflies in August and September will then return to the same mountains in Mexico that their great great grandparents used the previous fall.  

They are the only butterfly with such an advanced migration, a phenomenon that scientists still study.  


As I mentioned earlier, monarchs are now on the IUCN red list of threatened species.  The organization noted that its population has shrunk between 22 and 72% over the past decade.  Several causes are behind the decline such as logging and deforestation, climate change, and a decrease in the vital milkweed plant.  According to Monarch Watch, around 2.2 million acres of potential milkweed is lost in the United States each year.  

Monarchs lay their eggs on milkweed plants, of which Missouri has 17 native species.  Planting milkweeds, especially in areas where they are currently scarce is the best thing you can do to help them rear new generations.  

There are four types of milkweed that monarch seem to prefer for egg-laying purposes.  Butterfly weed, common milkweed, purple milkweed, and swamp milkweed.  All are fairly easy to grow and are easy to find at local nurseries and their flowers are a beautiful addition to any landscape.  When planting for monarchs, don't stop at milkweed.  Continue to feed the winged adults by offering other native plants like eastern blazing star, smooth aster, purple coneflower and wild bergamot.  

Find a native plant retailer in your area by visiting grownative.org.  To learn more on how you can help monarch conservation efforts, visit moformonarchs.org, monarchwatch.org, or missouriconservation.org.  I'm Jill Pritchard with the Missouri Department of Conservation encouraging you to plant milkweed, and to get your daily dose of the outdoors.  

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