Monarch Migration Update: Sept. 29, 2011
Please Report
Your Sightings!

"We're ready to host the monarchs!" Estela Romero reports from Mexico. Meanwhile, millions of monarchs are headed their way. Learn how to count monarchs this week, using standard units. "Our 4th grade counted 20 monarchs in 30 minutes!" Arkansas students say.

This Week's Update Includes:


Image of the Week
How many per hour?

News: Highlights Along the Migration Trail

Hola Desde Mexico
The Romero family watches for the monarchs' arrival in Mexico every fall, and serves as our local guides.

"I'll be announcing the big news to you in only a few weeks. Meanwhile, I'll share stories about our life, culture and traditions in our hometown."

A Butterfly Blizzard in Canada
It was Saturday morning when people suddenly began to see it. A blizzard of butterflies appeared along a 50-mile stretch of the Lake Ontario shoreline, roughly from Toronto to Niagra Falls, Ontario. What did it look like?

"They just kept coming! It was one of the most amazing things I have ever seen!"

"I was out walking my dog and suddenly noticed something quite extraordinary. A monarch butterfly floating past - then another, then another, then another... all following the same path..through the park, across the parking lot, down the path, over the roof, and out over lake Ontario. Quite an experience to find yourself in the middle of a migration!"

"Thousands! From 10 feet above ground to upper heights of 300 feet. Flew right over the house heading south."

All week, peak migration sightings have been reported along the Great Lakes of Ontario and Erie. Monarchs bunch up there, either waiting for safe crossing conditions or traveling along the shorelines.

Riding Ridges
Reports from the Appalachian Mountain region of Virginia have been particularly strong during the past week. The mountains are a monarch migration corridor. Monarchs can use ridge lift to gain altitude, and then soar effortlessly along the mountain ridges.

"My brother counted about 500 monarchs an hour crossing over Afton Mountain."

"While driving down the road near Fairlawn, VA, we started seeing monarchs everywhere in droves. We saw 55 in 30 minutes--then stopped counting. There were too many."

Funneling Toward Mexico
The migration map shows the leading edge of the migration now entering Texas, and peak conditions building across Oklahoma. Read sightings report from the region.

  • Are monarchs finding what they need in the drought-stricken landscape?


Estela, with her mother Lolita, and daughter Emilia.

Hola desde Mexico!

Monarchs nectaring on shore of Lake Ontaro
Butterfly Blizzard
Babs Smith




Monarch butterflies migrate along ridges for free lift.
Riding Ridges





Monarch butterflies land in Oklahoma garden for nectar.
Oasis in Oklahoma
Sandra Schwinn

Journal: How to Count Migrating Monarchs

Students in Akron, Ohio are among those who are monitoring the migration this fall. "We laid out by our school garden and saw the butterflies gliding overhead on their way to Mexico."

Notice how the following observers measured the pace of migration by counting monarchs per minute:

  • There were 30 monarchs in 95 minutes in Ripley, New York on Monday.
  • There were 20 monarchs in 30 minutes in Fayetteville, Arkansas on Tuesday.
  • There were 3 monarchs in 10 minutes in Akron, Ohio on Wednesday.

Who saw a stronger migration? Use this week's journal page to convert monarch observations to standard units and you'll see!

The Migration: Maps and Journal Page
Monarch Butterfly Migration Map: All Sightings, Fall 2011 Monarch Butterfly Migration Map: Fall Roosts, Fall 2011


All Sightings

(map | sightings)

Fall Roosts

(map | sightings | archives)

Seeing Monarchs? Please let us know!

Explore: Migration Rate Activities

Explore Migration Rate Activities to help students understand how and why standard units of measurement are used to analyze migration data.

With standard units, we can compare observations from one place to the next, one person to the next, and one time to the next.

Migration Rate Activities

Migration Rate Activities

The next Monarch Migration Update will be posted October 6, 2011.