Monarch Butterflies Part I – Milkweed, Metamorphosis, Migration!

26 Aug 2016

….stay tuned for Part II – Give Monarchs the Royal Treatment.  Monarch Butterflies offer us the chance to learn about so much more than just butterflies.  Discovering details about their migration allows us to become introduced to new people, places and cultures.  Learning about their natural history extends our outlook to conservation initiatives such as habitat restoration and protection.

Every Wednesday throughout the summer, Wye Marsh Naturalists are giving visitors the opportunity to learn about the past, present and future of North America, its people and the land that sustains us all through our ‘Wonder Wye’ demonstration about the Monarch Butterfly. Check out all of the topics of our Wonder Wye demonstrations!

Milk ‘weed’

“No species is inherently a pest…and any species can become one” – Aldo Leopold

Nearly any plant can be considered a weed if it is growing where it is not wanted.  Many of these so-called weeds are native to North America and often play a critical role in the complexities of an ecosystem.  Common milkweed (A.syriaca) is one such ‘weed’.  As a pioneer plant, milkweed is designed to pop up in disturbed habitats and cover the soil quickly, reducing the danger of soil erosion.  Milkweed was labeled a weed (and has subsequently been classified as a ‘noxious weed’) as it would invade farmers’ fields and result in sick cattle who would graze upon the plant.   But of course without milkweed monarchs cannot exist… 

The Journey Begins…

Monarch butterflies are not only attracted to the milkweed’s sweet nectar, but also to the plant’s ability to host the monarch caterpillar, which exclusively feeds on milkweed leaves.  The monarch’s journey begins with an adult female laying hundreds of eggs on the underside of a young milkweed leaf. When the caterpillar emerges about 3 days later he eats his egg shell for breakfast and continues to munch on the milkweed leaves for the next two weeks. The monarch caterpillar grows at an incredible rate – it gains 2,700 times its original weight!  If we could grow that fast, a 6 pound baby would end up weighing about 8 tons (the weight of a school bus)! It has gone from egg to caterpillar, and now, with plenty of energy packed into its body, it prepares for its next quiet stage of life, the pupa,  where it will remain for 14 days before emerging as a butterfly.  

But the Monarch’s tale is not over yet! In fact the butterfly’s most amazing feat – a journey of thousands of miles – is just about to begin.  Every fall (August-November) the annual migration to Mexico gets underway. By instinct alone, monarchs travel to mountain sanctuaries in Mexico where they have never been before.   Currently, it is the 4th generation monarchs that we are seeing flying about as they get ready to focus their efforts to fly south (as opposed to mating and laying eggs).


Did you know?

  • Monarch taste with the bottoms of their feet, as do all butterflies.
  • How long monarchs live depends on when they are born. Monarchs born in the summer months live only 2-4 weeks, with their primary focus being on breeding and building the population quickly.  Monarch who are born in the late summer/fall months live for 9 months as they migrate to and winter-over in Mexico.  If you were born in June, you would live 70 years, but if you were born in September you would live almost 1000 years!
  • Male monarchs have a black dot on their hind wings, while females do not.
  • Monarchs want to be noticed. Their bright orange and black colours say: “ stop! Look at me! I’m poisonous because I eat milkweed! Leave me alone!”

Learn more…

Monarch Watch – Get information on monarch rearing, tagging, butterfly gardening and research initiatives.  

Journey North – Report your sightings and track migration!

Monarch Teacher Network – A resource leader for educators.