Monarch Migration Update: March 14, 2013
Please Report
Your Sightings!
Report Your Sightings
As we wait for the mass departure from Mexico, the first sightings are appearing in the north. When and where will monarchs travel to find what they need this spring?

This Week's Update Includes:


Image of the Week
Monarch Butterfly EggLittle Egg, Big Hope
Photo: Elizabeth Howard
News: First Leaving, First Arriving
Mass Departure Imminent
Estela estimates half as many monarchs in the sanctuary this week and thinks the mass departure is imminent. Butterflies were streaming down the hillside as she drove up to the sanctuary on Saturday.

"The monarchs were traveling like passengers in a train, rushing to reach an appointment somewhere," Estela reports.

Population at Record Low
Mexican officials announced on Thursday that this winter's population hit a record-low, with butterflies covering only 1.19 hectares. There were more than twice as many monarchs last year. Although insect populations fluctuate naturally, scientists are concerned about the overall downward trend the graph shows.

For the classroom:
Slideshow: How Many Monarchs this Winter?
Population Graph: 1994/1995 to 2012/2013

First Sightings!
To the delight of observers in Texas, the first monarchs are beginning to appear. When monarchs were spotted in the Mexican state of Querétaro this week, the observer shared some local lore:

"These spring monarchs are called 'planters' because they pass as we prepare to plant corn. In November we call them 'harvesters' because they pass at the time of harvest."

Fewer Sightings
Only 5 sightings have been reported so far this spring, compared to over 100 last year at this time. (See map.) With the population so small, monarchs need high quality habitat to recover their numbers. The southern United States will be critical. The next generation will be produced there during the next 4-8 weeks.

Monarch butterfly sanctuary tour.
Streaming Flight
Monarch population hits record low in Mexico
Record Low

Did You Know?

A monarch colony contains 10-50 million butterflies in 1 hectare of forest.

Use the population chart to estimate how many monarchs were in Mexico each winter.

Monarch Butterfly Egg
Fewer Sightings
Slideshow: Spring Migration: A Journey Driven by Needs
Spring is a critical time for monarchs. As one generation reaches the end of its life, a new generation begins. This slideshow introduces the essential questions about spring migration. Prepare students to predict the path monarchs will travel based on what the butterflies need and where their spring habitat is ready.

Essential Question
When and where will monarchs travel to find what they need this spring?

Spring Migration: A Journey Driven by Needs
Get Ready: Spring Migration About to Begin!
The first monarchs should appear in Texas any day:
  • Use this letter to invite family and friends to help track spring migration.
  • Please report your monarch sightings.


All Eyes on Texas!
"The leading edge of the migration typically crosses the Rio Grande around March 15th," says Texas insect-expert, Mike Quinn.

Monarch butterfly migration map Map of milkweed emergence: Spring 2013

Journal Page

(map | animation | sightings)
(map | animation | sightings)
Next update March 21, 2013