Monarch Butterfly Update: March 15, 2012
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Here they come! Monarchs are leaving the overwintering sites and appearing on the breeding grounds to the north. During spring migration, female monarchs leave a trail of eggs behind as they travel. As you track the migration this spring, think of the hope embodied in tiny monarch eggs.

This Week's Update Includes:

Image of the Week
Monarch Butterfly Egg
Little Egg, Big Hope
News: Here They Come!
Leaving Mexico's Winter Sanctuaries
At the Beginning
As Estela watched from the hillside, hundreds of monarchs began their silent journey north with clear determination:

"Butterflies were coming downhill from El Rosario and flying northwest. They were streaming down the canyon in a small but beautiful cascade. From this point, the butterflies continue heading northwards, coming your way!

Fifty Miles Away
A stream of migrating monarchs was seen last Saturday about 50 miles north of the sanctuaries. The butterflies were passing at a rate of 35-50 per minute! Nobody knows exactly where the butterflies travel across northern Mexico so an observation like this is important.

Brower Expedition
Dr. Lincoln Brower just returned from Mexico. He was checking the status of the butterflies and habitat at the Chincua, El Rosario and Pelon colonies. He saw little evidence that the butterflies were leaving. However, he witnessed the behavior that immediately precedes depature. The butterflies were in a very active state, zooming around in the sky in a dispersive way. He expressed concern that the monarchs appear to be leaving too early. They shouldn't leave until last week of March, he believes.

Monarch butterfly sanctuary tour.
Photo: Estela Romero
Heading North!
Monarch Butterfly Biologist Dr. Lincoln Brower and party
Image: Dr. Lincoln P. Brower
Brower Expedition
Arriving on the Breeding Grounds
Surprisingly Far North
According to our observers, monarchs may already have spread more than 1,000 miles from the overwintering sites in Mexico. Our northernmost reports this week came from Oklahoma and Arkansas on Tuesday:

"Saw the first monarch today...One week earlier than in the past 3 years. A little faded, but majestic as always!" Portland, Arkansas

Did these monarchs come from Mexico, or did they overwinter in the United States? After such a warm winter, either is possible.

Wave Enters Texas
Observers reported a clear wave of arrival during the past week in Texas. Many people saw multiple monarchs:

"Spotted two monarchs passing through south Austin. After a rainy weekend, blue skies appeared Sunday and these beauties were seen heading north. Our drought has eased somewhat so everything is in bloom."Austin, Texas

Laying Eggs Along the Way
Field notes and pictures captured on Tuesday in Dobbin, Texas illustrate a day in the life of a migrating monarch. Take a look!

Migration Map Animation: March 7-14, 2012
Surprisingly Far North
Monarch butterflies nectar on pear blossoms in Texas.
Image: Kathy Metzger
Laying Eggs
Monarch butterflies nectar on pear blossoms in Texas.
Image: Kathy Metzger
The eggs!
Slideshow: A New Generation | The Life Cycle Continues
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?

A New Generation | The Monarch's Life Cycle Continues

The Migration: Maps and Journal Page
Let's find out when and where monarchs and milkweed appear this spring.
Monarch Butterfly Winter Sightings Map of milkweed emergence: Spring 2011 Journal Page
First Monarch
(map | animation | sightings)
First Milkweed
(map | animation | sightings)
The next monarch migration update will be posted on March 22, 2012.