Monarch Migration Update: Sept. 1, 2011
Please Report
Your Sightings!

Welcome to Journey South's fall migration season. As monarchs travel to Mexico through your hometown, what signs of migration might you see? This week, learn when, where, and how you can watch fall monarch migration. Please report your sightings!

This Week's Update Includes:

Image of the Week

Photo Gallery: Butterfly Eggs

Why leave now?

News: They're Off!

Flying, Resting, and Refueling
The monarchs are on their way to Mexico and excitement is in the air. Watch for monarchs that are flying in "directional flight," resting at overnight roosts, or refueling at flowers in fields, gardens, or roadsides. It can be tricky to tell if a monarch is migrating or not. Here are the signs people are seeing:

Every August, people in the north suddenly begin to report roosting monarchs. The butterflies cluster in trees to spend the night. This season's first fall roost was reported in Minnesota on August 11th:

"I noticed clusters of 10-15 monarchs flying and hovering in the trees in the back," wrote Mrs. Finley from Padua, MN. By August 24th, the roost had grown to 500 monarchs! "I went out to greet my little friends and they flew overhead in an amazing burst of color."

Monarchs feed hungrily in the fall. They must have nectar to fuel their migration. They must also eat enough nectar to gain the fat they'll need to survive the winter in Mexico. A Minnesota observer is counting nectaring monarchs in her garden. Here's what she observed during the past week:

"The monarchs are in full force on my sunny boulevard garden. For the last 4-5 days, their numbers have continued to grow. Midday counts of nectaring on blazing star liatris consistently reach around 30-35 monarchs. Last year we peaked at 60 butterflies around September 10th."

People are thrilled when they see monarchs flying toward Mexico. "Directional flight" means the butterflies are clearly flying in a southerly direction rather than fluttering about randomly. A teacher reported last Friday from Wisconsin:

"Seeing many monarchs in directional flight pattern. All flying the same direction, at the same height. Many stopping off in red clover fields to feed. My wife and I tagged 58 monarchs in about 2 hours. I am saving 17 tags for my second grade classroom."

Another Sign of Migration?
In many southern states, people rarely see monarchs during June and July. Monarchs re-appear in August, and nobody knows for sure where these monarchs come from. Are they early migrants moving down from the north? People in the south watch for their FIRST monarch at this time of year. Hammond School in Columbia, South Carolina, wrote enthusiastically on Monday.

"We saw our first Monarch in our new butterfly garden! On closer inspection, we have several monarch caterpillars munching on our milkweed leaves. WOW!"


Map Archives Spring Monarch Butterfly Migration
First Fall Roost!

Map Archives Spring Monarch Butterfly Migration
Field of Clover


Seeing Monarchs?
Report Regularly!

Tell us when and where monarchs are present.

Please report at least once a week.


Map Archives Spring Monarch Butterfly Migration
A First Monarch
Sighted in the South


Slideshow: When, Where and How to Watch Fall Migration

What kind of observations does Journey North collect in the fall, and how are they important? These questions are introduced and explored in this slideshow. Teaching activities include:

  • Data Hunt Challenge: students read and analyze sample observation reports.
  • Ask the Observer: students add details to "missing information" reports.
  • My Practice Report: students submit sample sightings reports to live map.



The Migration: Maps and Journal Page
Monarch Butterfly Migration Map: All Sightings, Fall 2011 Map of Monarch Butterfly Roosts: Fall 2010 Migration Migration map questions: Week 1

All Sightings

(map/ sightings)

Fall Roosts


For Your Journal
This Week's Map Questions

Seeing Monarchs? Please let us know!

The next Monarch Migration Update will be posted September 8, 2011.