Monarch Butterfly Update: April 21, 2011
Please Report
Your Sightings!

The monarchs from Mexico are reaching their final days, and a new generation is about to appear. Spring is a critical time for the monarch butterfly. This Earth Day, consider the monarch's need for renewal. Where is habitat most important in the early spring? A pie chart reveals clues.

This Week's Update Includes:

Images of the Week

Photo Gallery: Butterfly Eggs

Egg Hunt!

News: An End and a Beginning

An End and a Beginning
Only one month ago, Estela Romero was announcing the monarchs' mass departure from Mexico. Now, the butterflies from Mexico are reaching the end of the road. Increasingly this week, people noted monarchs that were "VERY faded," "ragged," and "translucent."

Signs of Change
By late April, the lives of most monarchs from Mexico will have come to an end. A new generation will continue the journey north. Here's what to watch for:

  • The number of sightings should drop very soon, as fewer and fewer monarchs from Mexico remain.
  • Sightings of fresh-winged butterflies are expected any time. (The first was reported from Texas on Saturday!)
  • The number of sightings will jump by mid-May, as more and more monarchs of the first spring generation appear.

School Visits!
To the surprise and delight of eager students, monarchs recently paid a visit to schools like these:

4/14/11: Greenville, South Carolina
Just as Ms. Williams' class was transplanting milkweed into their garden, "Mother Monarch joined us and actually placed eggs on plants we planted. She stayed with us for the whole project time, laying eggs."

4/14/11 Marietta, Georgia
"We spotted an adult while on a biodiversity scavenger hunt," exclaimed students at Nicholson Elementary.

While students were on the playground and at recess, they spotted monarchs in Mableton, Georgia, La Cygne, Kansas, Fayetteville, Arkansas and Fairfax, Virginia. Way to go! Keep up the great work.

Happy Earth Day, Monarchs
We celebrate nature's power of renewal on Earth Day. For monarchs, the need for renewal is especially clear at this time of year. The number of adult monarch butterflies is at its lowest; at no other time of year are there so few monarchs. Exactly where on Earth is habitat most important for monarchs in the early spring?

Temperatures were much colder this week than last week.

Fading Fast


Proof of early monarch butterfly sighting in Missouri

A Picture to Prove It!


Egg-loading in Tennessee

Egg-loading in Tennessee



Pie Charts: Where is Spring Breeding Habitat Most Critical?

Temperatures were much colder this week than last week.

Data Table: Sightings Reported as of April 21, 2011

Temperatures were much colder this week than last week.

This Year Data Table Last Year

Over 400 monarchs have been reported so far this spring. Let's look at their state-by-state distribution to see where spring breeding habitat is most critical. Use the monarch sightings in the data table and calculate percentages for each state, then label your pie chart. Check out last year's state-by-state pie chart for comparison. See sample sentence starters for data analysis.

Photo Gallery: A Dozen Butterfly Eggs

Explore the science and wonder of butterfly eggs by looking closely at images of magnified eggs. Small things become extraordinary when they are keenly observed!



Butterfly Eggs

A Dozen Butterfly Eggs

The Migration: Maps and Journal Page
Pre-migration map: Winter monarch butterfly sightings (January or February) Map of milkweed emergence: Spring 2011 Journal Page
Which states are most important for monarchs in springtime?

Let's find out when and where monarchs and milkweed appear this spring.

The next Monarch Migration Update will be posted on April 29, 2011.