Monarch Migration Update: Sept. 27, 2012
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As monarchs wing their way to Mexico this fall we're seeing an unusual pattern—large numbers in the east and small numbers in the drought-stricken Midwest. Does this pattern mean fewer monarchs will make it to Mexico?

This Week's Update Includes:

Image of the Week
Monarch butterflies roosting in Ontario
Leaving Canada
Patty Moss
News: Wave Hits Great Lakes and Appalachians
Leaving Canada
Fall arrived this week, and a burst of butterflies was reported from the Canadian Great Lakes region. Point Pelee National Park reports:

Sept: 19: "Finally, a decent number of monarchs. The count was 800 monarchs. Perhaps the Canadian monarchs are beginning to move. There was also mention of frost in northern Ontario last night - that should hurry them along."

Sept. 22: "I observed about 600 butterflies per hour moving southwest from 11:30 AM until around 2:00 PM. Migration stopped around 2:00 PM when it clouded over and temperatures fell into mid 50's." Steve Rankin, Clearville Park, ON

Following Atlantic Coast
The monumental migration on the Atlantic Coast continues! Cape May, NJ has become a hotspot.

"It was like a snow globe today as the brilliant orange monarchs flew against the bright blue sky!!!! It's glorious to see them flying around our town — it's a little Mexico here at home." Paige Cunningham

Riding Appalachian Ridges
The peak migration map shows a string of reports along the Appalachian Mountains this week. Did these monarchs move inland from the Atlantic? A Virginia student saw a sudden wave:

"When I was at recces I saw 37 butterflies going south for the winter. It was Friday, September 21st. It was about 3 butterflies coming at once. We saw all those butterflies in 15 minutes. A couple of them went west but they came back and went the right way. We have been seeing like 1 or 2 a day but last Friday was the most." 2nd grade girl, Monroe, VA

Entering Oklahoma
At last! A single roost has been reported in Oklahoma. As the picture shows it was small, only 55 butterflies. The migration's arrival was quite clear:

"Monarchs are migrating across central Oklahoma! From 5pm to 5:45pm, I counted 20 in a directional southerly flight. We remain in extreme drought conditions. It's been a challenge to keep the grasshoppers from decimating the flowers intended for the migrating monarchs." Linda S., Kingfisher, OK

Compare Years
Roost maps show where large numbers of monarchs are concentrated. With most of this year's population coming from the east, the pattern raises a concern:

  • How many monarchs will make it to Mexico?

Watch Texas
All monarchs must cross Texas to get to Mexico. Keep an eye on the migration map. Will we see a wave of arrival from the east?

Map showing journey of tagged monarch butterfly.
Tagged Monarch Found!
Roosting Monarch Butterflies in Cape May, New Jersey
Atlantic Roost
Image: Jacquie Davis

Monarch butterflies migrate along ridges for free lift.
Riding Ridges
First Oklahoma Roost

First Oklahoma Roost
Image: Sonia Kirk

Fall Migration Comparative Maps
Compare Years
Explore: Migration Rate Activities
The migration is becoming more concentrated now. People can count monarchs flying overhead. Help students understand how and why standard units of measurement help us analyze migration data.

Try This!


How many per hour?
The Migration: Maps and Journal Page
Watch for monarchs that are flying in directional flight, resting at overnight roosts, or refueling at flowers in fields, gardens, or roadsides.
Seeing Monarchs?
Report Weekly!
When you see a monarch, we want to know about it.
Monarch Butterfly Migration Map: All Sightings, Fall 2012 Monarch Butterfly Migration Map: Peak Migration, Fall 2012


All Sightings
(map | animation | sightings)
Peak Migration
(map | animation | sightings)
The next migration update will be posted on October 4, 2012.