Migration Update: October 15, 2009
Please Report
Your Sightings!

This Week's News:

Photo of the Week

Photo: Marceline Vandewater

Where do Arizona monarchs go for the winter?

The Migration: Maps and Questions

Fall Roosts


Migration Events


ALL Monarch
Migration Sightings


Distribution Map

Learn About Migration Maps


Make Your Own Migration Map

For Your Journal
This Week's Map Questions

Latest News

Monarchs on the Move in Arkansas and Texas
"Look UP! Skies have cleared and directional-flight monarchs are passing through Fair Oaks Ranch, Texas, this morning!" wrote Mary Kennedy on Wednesday.

The same day, an observer in Little Rock, Arkansas, reported the same change: "It has been so rainy here for a week but this afternoon the sun is breaking through. In the space of around 30 seconds, I spotted 48 monarchs."

Observers in Abilene, Texas, reported strong migration all week. Three different people reported the migration rates below. Convert them to "monarchs per hour" and notice how consistent these migration observations are:

  • 200 monarchs in 15 minutes
  • 20 monarchs in 1 minute
  • 98 monarchs in 5 minutes

Curiously Quiet in Northern Mexico
Why have there been so few reports from northern Mexico? "They're only coming through in small numbers," says Rocio Treviño whose network of volunteers tracks monarchs across Mexico's north. She wonders, will the monarchs flood across the border in the coming week? Are they taking a more westerly route this year, through the state of Chihuahua? Columbus Day, October 12th, is the day she says the monarchs traditionally arrive. Why are they late and what will happen next?

High Migration Rates Continue Along Atlantic Coast
Large numbers of monarchs moved down the Atlantic Coast this week.
"Week 6 continued the upward trend in the number of monarchs seen on our Road Census. Claire Iseton recorded 113 monarchs on the morning census on October 10," reports The Monarch Monitoring Project in Cape May, New Jersey.

Observers along the Atlantic Coast from New Jersey to Virginia reported monarchs in similar numbers. Suddenly, thousands of butterflies per hour were reported from Florida's Gulf Coast. Even before seeing the pictures we had clues the butterflies would not be monarchs. What clues do we look for? (Read on...)

Thousands of butterflies per hour reported from Florida's Gulf Coast—but are they monarchs?
What clues do we look for?

News from the Monarch's Winter Home: Spanish & English

Two monarchs were sighted in Angangueo, Estela Romero reports this week. Why does monarch scientist Dr. Lincoln Brower suspect these butterflies were local monarchs, not migrants from the north?

Maria Estela Romero
reports from Angangueo.

Slideshow: Where do Arizona Monarchs Go for the Winter?

Chris Kline was curious about migration patterns in Arizona. He explains, "It is well accepted that monarch butterflies east of the Rocky Mountains travel to the mountains near Mexico City during the winter. Monarchs west of the Rockies migrate to the coast of California. Since Arizona is south of the Rocky Mountains, where do monarchs go? Or, do they go anywhere at all?"

Cline founded the Southwest Monarch Study, and his Arizona team has uncovered fascinating new information. Recoveries of their tagged butterflies raise important questions about why monarchs migrate where they do.

Links: Monarch Resources to Explore

Monarch Butterfly Migration Updates Will be Posted on THURSDAYS: Aug. 27, Sep. 3, 10, 17, 24, Oct. 1, 8, 15, 22, 29, Nov. 5...or until the monarchs reach Mexico!

The Next Monarch Migration Update Will Be Posted on October 22, 2009.