Monarch Butterfly Update: April 28, 2011
Please Report
Your Sightings!

With cool temperatures across the north, the monarchs appear to have moved eastward instead of northward. While the number of sightings continues to fall, fresh-winged butterflies are also appearing. This week, take a look at mystery monarch photos. Can you guess what these unique objects do, based on how they look?

This Week's Update Includes:

Image of the Week

Photo Gallery: Butterfly Eggs

What Do You See?

News: Stalled at Latitude 40N

For over two weeks, the migration has seemed stuck below latitude 40N. Watch the animated migration map and see how monarchs build below that line, not venturing northward.

A Jump to the East
Instead of northward, the migration made a clear move to the east this week. Of the 35 sightings reported, 71% were from the eastern states. Virginia alone reported 30% of the sightings!

"There was a gust of wind (17 mph) coming from the SSE, there she floated in," wrote Mona Miller from Virginia. "She is definitely faded..."

"Greetings again from Virginia's Eastern Shore! Saw a female monarch frantically trying to lay as many eggs as possible on very short stalks of milkweed in a large pot!"

Cold North, Warm South
This temperature map shows a pattern that may help explain the monarchs' movements. Cool spring temperatures have persisted across the north, but the south has been warm.

Cool temperatures in the Central Plains, where the migration arrived early two weeks ago, have slowed monarch development dramatically. For example, it took 12 days for the eggs to hatch in Mrs. Dunagan's Illinois garden. (Eggs hatch in only 2-3 days during warm summer temperatures.)

Consequences of Cold
This observation illustrates some disadvantages of migrating north too quickly: Monarchs develop into butterflies more slowly. This means they are also exposed to potential predators for a much longer time.

Carried Away! Early Monarch in Michigan
A warm air mass finally broke into the north on Tuesday, and a monarch appeared in southern Michigan. As the picture shows, the trees don't even have leaves yet!

  • Journal: Take a look at this wind map. What were the conditions on the day of this early Michigan sighting?



Female monarch discovers milkweed waiting for her in Virginia!

Faded Female in Virginia

Temperature Map

Cold North, Warm South

Larvae in Illinois


Temperatures were much colder this week than last week.

Early Monarch in Michigan

Monarch Mystery Photos: Exploring Form and Function in Nature

These magnified photos reveal small, intricate structures. They reveal a relationship between form and function in nature. Can you guess what these structures do, based on what they look like? Take a look!



Monarch Mystery Photos: Exploring Form and Function in Nature
Monarch Mystery Photos

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 way was the wind blowing?

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

Annual Evaluation: Please Share Your Thoughts

Please take a few minutes to complete our Annual Evaluation. With your help, we can we document Journey North's reach, impact and value. Thank you!

The next Monarch Migration Update will be posted on May 5, 2011.