Migration Update: April 10, 2008
Please Report
Your Sightings! >>

Today's Report Includes:

  • The Migration: Maps, Questions and Highlights
    • Stalled to the North, Expanding to the East >>
    • Make Room on Your Map: More Are Monarchs Coming Soon! >>
    • Climate and Migration >>
    • Why Go East? >>


Dr. Lincoln Brower, Sweet Briar College

Monarch Mystery Photo >>

The Migration: Maps, Questions and Highlights

 

Map/Animation/Sightings

Map Questions >>

Highlights: Stalled to the North, Expanding to the East

This is a fascinating time of the migration. Notice how far east the monarchs have gone and how little they have moved to the north. If we measure from a central point in Texas (San Antonio), the monarchs have flown 1,000 miles to the east and only 500 miles to the north. They'd be in South Dakota by now had they gone straight north. Yet, for nearly two weeks, the northernmost monarch on our map has not surpassed the Oklahoma sighting at latitude 37 N. Meanwhile, the monarchs have jumped eastward — across Arkansas, Mississippi, Alabama, Georgia and Tennessee where on Monday....

"The first grade class at Union Elementary in Gallatin, TN, was pulling weeds in the vegetable garden when a monarch butterfly flew over our heads. The monarch was faded but beautiful. We were excited to see one return from the long journey from Mexico. We have a butterfly garden by the fence but the milkweed and butterfly weed have not emerged yet. The monarch did not stop."

Monarchs were also reported this week from North and South Carolina. Did those monarchs came up from Mexico? Biologist Billy McCord tagged monarchs on the South Carolina coast this winter. His results suggest that some monarchs survived all winter along the coast.

  • Read about tagging monarchs on the South Carolina coast >>
  • Watch the animation. Do you think it suggests that the Carolina monarchs are from Mexico? >>
  • Predict where the monarchs will go next! Add 4 new states to your list of states where the migration has arrived. Make your predictions and record the results on this Prediction Chart.
Make Room on Your Map: More Are Monarchs Coming Soon!

New butterflies of the next generation are about to be born! The monarchs that entered Texas and began laying eggs the week of March 15th had spread across the state within a week. (See map below.) Eggs collected on March 21st by Carol Cullar in Eagle Pass hatched on the 24th and began going into the chrysalis stage on April 6th. According to her prediction, these new monarchs should appear by April 15th. Temperatures have been mild and the full cycle should take only 26 or 27 days. "We've had mild weather with temps mostly in the 80s," she explains.

Climate and Migration >> Why Go Northeast? >>

What effect do temperatures have on the pace of migration? Here are migration and temperature maps over four years for you to compare. Take a look!

The orange arc on this map shows where monarchs would be now if they had spread equally in all directions. Why do they advance most quickly to the northeast?

Slideshow: Do You Know a Monarch When You See One? >>

Every spring and fall we rely on hundreds of observers to track the monarch's migration. These observers expand the eyes and ears of scientists in ways not possible before the Internet. But their observations must be accurate in order for the data to be valid and useful. Remember: Our migration maps are only as accurate as the people who report observations.

Can you identify a monarch from its look-alikes? Please practice! >>

Challenge Question #9: Did These Observers See Monarchs? >>

This week, read some of the real, questionable observations that have been reported to Journey North.

Challenge Question #9:

  • Do you think these observers saw monarchs? Decide whether these sightings should be included on the migration map. Give reasons for your decisions. >>
  • Answer to last week's Challenge Question #8 >>
 Links: Monarch Butterfly Resources to Explore
More Monarch Lessons and Teaching Ideas!

The Next Monarch Migration Update Will Be Posted on April 17, 2008.