Monarch Migration Update: Sept. 23, 2010
Please Report
Your Sightings!

A migration of historic proportions took place along the Atlantic coast last week, and the leading edge of the migration entered Kansas. Read the first weekly news report from Angangueo, Mexico. Also, find out how high monarchs fly, and how high we can see them. These facts are important. After all, we're tracking migration based on visual observations.

This Week's Update Includes:

Image of the Week
Toronto skyline: Monarch butterflies were sighted from a 22nd floor office building here.

How high do monarchs fly?

News: Stop and Go, All the Way to Mexico

The migration moved in clear pulses last week. One day would be quiet. The next day monarchs would be "floating," "gliding," and "soaring"—past people in office buildings, drivers in their cars, families at backyard barbecues, and a surfer riding waves.

Atlantic Coast
A reader wrote to complain:

"We made a special trip this past weekend to (New Jersey's) Long Beach Island to see this magnificent butterfly migration and we ONLY counted 12 the entire weekend."

Unfortunately, monarch migration is highly variable and unpredictable. Look what happened the same weekend, only 70 miles down the New Jersey shore! Dick Walton from the Cape May Monarch Monitoring Project reports:

"An orange blizzard hit.... Even by historic standards this was a huge flight. On the 3 road-census runs on September 18th (volunteers) recorded 1,592 monarchs in a total of 60 minutes of observation!"

The day before, a massive migration was reported up and down Long Island's beaches. Among the New Yorkers who witnessed the event were Woodhull School's 2nd and 3rd graders:

"We took a walk down to the beach and saw thousands and thousands of butterflies migrating."

Central Pathway
Persistent south winds seem to be holding many monarchs back. Almost daily, peak migration reports from Prairie City, Iowa, show substantial numbers and the effect of the wind:

"Monday was sunny and warm with a strong wind from the south southeast at 20-25 miles an hour. During a late afternoon visit to Neal Smith National Wildlife Refuge, 80 monarchs were observed in an hour. Several were noted fighting the wind, but most were found nectaring on wildflowers on a forested hillside and stopping to rest on the branches of oak trees."

When the wind and weather are right, reports like this one from Lindsborg, Kansas, show monarchs on the move:

"We were having a bbq in the yard on Saturday. The wind had been coming out of the south. At around 6.00 pm it changed and started coming out of the north. Within a few minutes we began to see the monarchs coming out of the north. Some were low but the majority of them were very high up--and there were hundreds of them."

Angry Atlantic Ocean

An angry Atlantic Ocean as seen from Long Island, New York on September 17th.

Monarchs found safety in trees nearby.
Images: Chris Paparo

Angry Atlantic Ocean

Research Questions: How high do monarchs fly? How high can we see them?

Monarch migration can be invisible to us when we watch from the ground. There is a large gap overhead where monarchs can travel and we can't see them. How high can monarchs fly and how high can we see them? These questions are important because we are tracking migration based on visual observations. Our migration maps only show what people are able to see!

1) Find out what scientists know — and don't know— about the height of monarch flight. 2) When do monarchs disappear from view? Design your own experiment or try one of ours.
How high can we see them? How high can monarchs fly?

When we watch migration from the ground, there is a large gap overhead where monarchs can travel and we can't see them.

Did You Know?
When we watch migration from the ground, there is a large gap overhead where monarchs can travel and we can't see them.

From Angangueo: A big hello and open doors to the monarchs!!!

Many readers have asked about the rebuilding of Angangueo after last February's flood. Estela Romero, Journey North's local reporter, sends an update. She shares a true sign of her family's strong spirit: Their store--that had been open for 91 years without interruption--has reopened! Here's Estela:

"Dear Journey North friends, A new season is opening in our region. As we await the Monarch´s arrival we want to say HELLO to you in several different ways:



Independence Day celebration in Angangueo

Our family store has reopened!
Before the flood, our store had had 91 years working without interruption.

The Migration: Maps and Journal Page 
Map of All Monarch Butterfly Sightings: Fall 2010 Map of Monarch Butterfly Roosts: Fall 2010 Migration Journal Page

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 September 30, 2010.