Monarch Butterfly Update: March 1, 2012
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Your Sightings!
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The first migrating monarchs have been seen, and the millions remaining are running low on fuel. March is here and it's a time of great change. Do you have questions about monarchs? Ask the Expert is now open.

This Week's Update Includes:

Image of the Week
Monarch Butterfly expert Dr. Karen Oberhauser
Ask the Expert
News: Spring is Coming, Fuel is Falling
First Butterflies Coming!
The first of sign of migration was just reported from the northern edge of the sanctuary region:

February 29: "Here come the monarchs! I observed a good number of butterflies migrating toward the north yesterday. I was able to see them on the stretch of road between Contepec and Maravatio," reports biologist Eligio Garcia, courtesy of Rocio Trevino.

Many millions of monarchs will remain at the sanctuaries until mid-to-late March, but this is the first sign of departure. With each passing day, the mass exodus is getting closer. Temperatures are rising. Monarch activity is at a frenzy on warm, sunny days. Mating increases dramatically now, and the butterflies are leaving their clusters continually to head out in search of water.

Fuel is Falling
The monarchs are running low on fuel. Look at the falling lipids on this line graph based on Dr. Lincoln Brower's research. How much longer could the monarchs stay in Mexico before they'd run out of fuel? Running out of fat is a common cause of mortality. Many monarchs simply starve.

Drought and Lipids
Lipid levels are of particular concern this year because of the drought in Texas and northern Mexico. Last fall, little nectar was available when monarchs traveled through that drought-stricken habitat. Normally, the butterflies would eat hungrily in that region to gain lipids for migration and winter survival. Scientists have been concerned whether monarchs would have enough lipids in reserve to sustain them this winter.

Recovering Tags
This week, Estela traveled with volunteers from Monarch Watch to gather tags people have found in the oyamel forest. "Some people brought only 2 tags but some brought many more, as many as 100. These were tags found during the previous winter. Sharing this couple of days with Diane and Debbie from Monarch Watch has been one of the most enriching experiences I have had in my education about the monarch's life and migration," reports Estela.

Map of monarch wintering sites in Mexico
Sanctuary Region
Monarch butterfly sanctuary tour.
Image: Estela Romero
Activity at a Frenzy
Monarch Butterfly: Graph of lipid mass by month.
Image: Dr. Lincoln P. Brower
Fuel is Falling
Attention Butterfly Gardeners
Hungry monarchs will be coming your way!
Recovering Monarch Butterfly Tags, Photo Gallery
Photos: Estela Romero
Recovering Tags
Slideshow: No Food for Five Months?
People eat three meals a day, 365 days a year. How can monarch butterflies survive for so long without food? This slideshow shares their secret.

Essential Question
Where, when and how do monarchs get the energy they need to survive the winter?

Monarch Butterfly Slideshow: No Food for Five Months?

The Migration: Maps and Journal Page
Before spring migration begins, please help document where monarchs are being found and where milkweed is available.
Monarch Butterfly Winter Sightings Map of milkweed emergence: Spring 2011 Worksheet: Journal Page
First Monarch
(map | animation | sightings)
First Milkweed
(map | animation | sightings)
The next monarch migration update will be posted on March 8, 2012.