Monarch Migration Update: May 20, 2010
Please Report
Your Sightings!

Monarchs, monarchs (almost) everywhere! An outbreak of sightings occurred during the past week in the Upper Midwest, and egg-laying was substantial. We welcome this burst in numbers every May, but this year especially. What other creatures inhabitat the milkweed patch? This week, meet some of the monarch's neighbors and find out who their enemies are.

This Week's Update Includes:

Image of the Week

Meet the neighbors!

News: An Explosion of Sightings—and Eggs Too!

A sudden explosion of sightings is taking place as the migration expands across Iowa, Indiana, Wisconsin, Illinois, Michigan, Minnesota and Ontario. The butterflies are laying vast numbers of eggs as they move into this new territory. Take note:

  • More people reported egg-laying during the last 7 days than during any previous week this spring.
  • Of this spring's total egg reports, 25% were made during the past week.
  • Look at the map of monarch egg reports and you can plainly see, a new region has become important for monarch reproduction. Go monarchs!

Here are some of this week's comments. Notice how the sight of monarch eggs proves the migration has arrived:

May 15: "We have yet to see a monarch in our area, but I discovered one egg on common milkweed in our milkweed garden." Burnsville, Minnesota

May 15: "I did not see the monarch that laid 11 eggs on the milkweed in my field, but she was here!" Lafayette, New Jersey.

May 18: "I was in the restored prairie with 25 of my students monitoring this afternoon, and we found our first egg after looking at over 300 milkweed plants." Chanhassen, Minnesota

A Day in the Life of an Egg-laying Monarch
Imagine a monarch flying across the landscape, looking for milkweed as she travels. A monarch can produce hundreds of eggs in her brief lifetime, but how many does she lay each day? This graph shows 33 days of egg-laying by a captive monarch.

  • Try this! Challenge yourself to find one milkweed plant for each of the eggs a monarch can lay per day, based on this graph. Do you think you could find 758 plants in 33 days?

Also Noteworthy:
Nebraska students at J.P. Lord School in Omaha were the first to report monarchs from their state!

"Our students spotted the first monarch fluttering around the buses as the children were coming into the school. Our classroom is aware of the large migration of monarch look alikes and we are absolutely certain that this butterfly was a monarch!"


A new region for reproduction


Photos: Sue Fox McGovern

Ovipositing in Illinois
"She landed in our common milkweed patch and began to lay eggs on various leaves," wrote Sue Fox McGovern.

How many eggs per day?

The Migration: Maps and Journal Page 



This year's small monarch population means spring sightings are especially important. Please help us document when and where monarchs and milkweed appear this spring.

Explore: Who's Who in the Milkweed Patch?

Meet some of the creatures that live in the milkweed patch. How do they make a living? There are carnivores, herbivores, nectivores, and scavengers. There are predators and parasites, too.

Look closely at the pictures in the photo gallery, read the descriptive clue cards, and see if you can figure out who's who!

Did you know?

  • The chemicals in milkweed do not fully protect monarchs from all of their enemies. Monarch eggs and larvae have many predators and parasites.
  • Scientists estimate that fewer than 10% of monarch eggs survive past the first instar larval stage.


Photo Gallery

Clue Cards

Book Review: Monarchs, Milkweed and More

"The milkweed community is a stage for a season-long series of dramas involving a cast of fascinating characters," begins this field guide. The pages that follow are packed with images of the invertebrates who lives their lives, generally unnoticed, right beneath our noses.

This handy guide introduces the reader to the kinds of creatures that come and go from the lowly milkweed patch, each with a job to do: herbivores, nectivores, scavengers, decomposers, predators, and just plain passers-by. But beyond a simple identification guide, this book portrays the complex interactions between these backyard creatures and delivers what's promised, "A fascinating glimpse into the complex interdependence of life on our planet."

Milkweed, Monarchs and More
by Rea, Oberhauser and Quinn.

Year-end Evaluation: Please Share Your Thoughts

Please take a few minutes to complete our Year-end Evaluation. With your help, we can we document Journey North's reach, impact and value. We need comments like yours to keep the program going and growing.

More Monarch Lessons and Teaching Ideas!

The Next Monarch Migration Update Will Be Posted on May 27, 2010.