Monarch Migration News: September 10, 2015
By Elizabeth Howard
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People are counting monarchs roosting by the hundreds, feeding by the dozens, and flying overhead at rates up to 2 per minute. Comparative counts reveal migration pathways to Mexico.

Monarch Butterfly Migration: The Overnight Roost
Amy Lewis hosted a roost of 1,000 on Tuesday night in Perrysburg, Ohio.

News: Sailing Southward
The season's first strong cold front sent monarchs sailing southward from the Upper Midwest this week. It's two weeks before the equinox. Fall conditions are setting in as the jet stream dips south.

Unusual Pattern
Why are so many roosts being reported from Ohio this year before any from Canada? In previous years, Canada's roosts have always preceeded Ohio's. Typically, we see monarchs traveling along the northern shores of Lake Ontario and Lake Erie and roosting along the way.

  • Will we see a later pulse of monarchs coming down from Canada's north shores?
  • Is Canada's final generation developing late — or was production low this year?

Counting Monarchs
When you watch migrating monarchs, find ways to quantify (count or measure) what you're seeing. For example, tell us how many monarchs you count per minute — or how your observation compares to what you saw yesterday, last week, or last year.

Migration Rate: 2 per minute
"While sitting at railroad crossing waiting for train, a string of 21 monarchs flew overhead in a matter of about 10 minutes. There were a couple small groups of 3-5."
Red Wing, Minnesota September 7, 2015

Looking Ahead
Watch the roost map for reports from the northern shores of Lake Ontario and Lake Erie. Migration from Canada is off to a slow start; it typically peaks the week of September 19th.

Jet Stream Dips South
Lyndon State Meterology

Monarch Butterflies Nectaring During Fall Migration

Garden Count
Darrick Olson

Monarch Butterfly With a Tag

Tagged Monarch Found!
Bill Jarvis

Spotlight: Tagging Study Published
The results of an 18-year tagging study were recently published by citizen scientist, Gayle Steffy. What insights are revealed about fall migration?

Monarch Butterfly
Betty Mattson

Maps: Report Your Sightings
What to Report to Track Fall Migration Monarch Butterfly: Adult Sighted Monarch Butterfly: Egg or Larva Sighted
What to Report Adult Butterflies
map | list | animation
Eggs and Larvae
map | list
Monarch Butterfly Migration Map: Fall Roosts, Fall 2015 Monarch Butterfly Migration Map: Peak Migration Fall 2015 How You Can Help
Fall Roosts
map | list | archives | animation
Peak Migration
map | list | animation
Journal and Activities
Next Update September 17, 2015