Monarch Migration Update: Oct. 28, 2010
Please Report
Your Sightings!

"It's official!" says Estela Romero. The first monarchs have reached their winter home in Mexico. Meanwhile, it's peak migration across northern Mexico as the butterflies funnel homeward. This week, explore the possible pathway monarchs take. Why does Dr. Calvert say it's "delightfully confusing"?

This Week's Update Includes:


Images of the Week
Images of Mexico
Photo: Google Earth

What does Mexico
look like?

News: First Monarchs Reach Winter Home in Mexico!

"The monarchs are here!" exclaimed Estela Romero last Friday. After watching for them daily—and recording zeros on her chart since the first of October—she greeted the monarchs with enthusiasm:

Only 60 miles north of the overwintering region, Naomi Suss watched monarchs flying overhead on Tuesday evening: "They are flying high and fast, so I think many of them will arrive at the reserves today," she wrote from her home in Tequisquiapan, Querataro.

Peak Migration Across Northern Mexico
"Butterflies are flying all along their migration route in Mexico," reports Señora Rocío Treviño who coordinates Mexico's migration-tracking program, Correo Real.

"People are reporting monarchs now from the northern state of Coahuila all the way to Michoacan. We have a large gap, for lack of reports, in the states of San Luis Potosi, Guanajuato and Queretaro," says Rocio.

She encouraged everyone to enjoy the monarchs and, as the song says:

Spanish English
abre tus ojos
mira hacia arriba
disfruta las cosas buenas
que tiene la vida!
open your eyes
look up
enjoy the good things
that life has!

Migration Continues from the North
It's almost November but monarchs are still migrating out of the north.
Look at the map of all monarch sightings and see if you can find:

  • The northernmost monarch recently reported.
  • The last date a monarch was sighted in Canada.
  • The latest news from the Texas Gulf coast.


This cluster of monarchs among the first to reach their winter home in Mexico.

They're Home!

These monarchs are among the first to reach their winter home in Mexico!

Just look at the chart today!

When did the first monarchs arrive?

Estela Romero recorded zeros on her chart until the first monarchs finally appeared.

Rocio Trevino

Señora Rocío Treviño

Coordinator of Mexico's migration-tracking program, Correo Real.

Nonfiction Reading: Explore the Possible Pathway in Mexico

The direction the monarchs travel is "delightfully confusing!" writes monarch expert Dr. Bill Calvert.

Which Mexican states do the monarchs cross as they travel to their winter home? Why don't the monarchs travel straight south?



Monarch butterfly migration pathway in Mexico

Explore the possible pathway in Mexico.

The Migration: Maps and Journal Page 
Map of All Monarch Butterfly Sightings: Fall 2010 Map of Monarch Butterfly Roosts: Fall 2010 Migration Make a map of the monarch migration pathway

ALL Monarch


Fall Roosts


For Your Journal
This Week's Questions

Seeing Monarchs? Please let us know!

  • Report frequently—at least once a week—as long as monarchs are present.
  • Count monarchs: Tell us how many monarchs you see per hour (or minute).
  • To report your sightings, press here.
The next Monarch Migration Update will be posted on November 4, 2010.