Monarch Butterfly Migration Update: April 4, 2003

Today's Report Includes:

• News From Along the Migration Trail
• The Journey Home: Final Notes from Dr. Calvert’s Mexico Travels
• The Life Cycle Begins!
• Do People Have Instincts? Interview a Human Parent
• A Day in the Life of a Butterfly Egg
• Insect Reproduction Strategy: Large Numbers, Raised by Mother Nature
• The Story of the Female Who Laid Many Eggs
• Eating Eggshells: The Monarch's First Meal
• Where Do All the Monarchs Go? Challenge Question #14
• My Monarch Habitat in...Discussion of Challenge Question #13
• Challenge Question #15: Where’s The Next Mystery Monarch Habitat?
• Answers from the Monarch Expert

• Link to Data: Link to This Week's Data

If you’re keeping track of the state and provinces the monarchs have reached, predict where you think they’ll arrive next?

• Link to: Predicting the Route of the Monarch’s Spring Migration

The Journey Home
Final Notes from Dr. Calvert’s Mexico Travels
Drs. Calvert and Edson finally arrived home, after their long journey along the migration pathway in northern Mexico. Special thanks to Jim Edson for these terrific photos of the region!

Between Rio Corona and the U.S. border	On the way to the swimming hole	The swimming hole
Jim Edson at the Tropic of Cancer (23.5 North)	Resting during the long migration	Bill Calvert's van at Rio Corona

Said Dr. Bill, “Basically, adults were not seen flying during the day. We assumed that they were way up high. We found them in the evening about 5:30 - 6:30 PM along rows of trees, or during the day in cool riparian areas. This is often what we see along the southward migration - nothing during the day and then a fallout in the afternoon or evening. But sometimes on the southward migration we would see enormous numbers flying low during the day.”

Inspecting milkweed for eggs and larva

Milkweed does occur in the region, and monarch eggs and larvae were found but “the milkweed densities were never what I have encountered in fields in Texas or further north," and "nothing that would lead one to believe that gravid and eager females were loading plants with eggs as fast as they could.”

• Full Text from The Journey Home: Dr. Calvert’s Mexico Travels

Can you find the butterfly in this picture?

First comes the egg: Take a close look at that tiny cream-colored dot. Carried inside are all of the instructions a monarch needs to be a monarch. The egg will change from larva to chrysalis and adult, and then the cycle will begin again. Through each stage the same genetic information will travel such that next fall, several generations hence, an adult butterfly will migrate back to Mexico. All this happens by instinct alone!

As you learn about each stage of the monarch life cycle this spring, keep a list of all the things monarchs do by instinct.

Do people have instincts? Throughout history and around the globe, several specific human behaviors occur during the first year of life. Do parents teach their babies to smile? To crawl? To stand or to walk? Interview a parent about a baby they watched develop (maybe you!). Record the dates each of the events occurred for the first time, and explore the world of instinct.

• Do People Have Instincts? Interview a Human Parent

• A Day in the Life of a Butterfly Egg

In the wild, monarchs would never lay this many eggs on a single leaf as they do in captivity. (Photo: Dr. Karen Oberhauser's lab)

• Insect Reproduction Strategy: Large Numbers, Raised by Mother Nature

Courtesy of Jim Edson

• The Story of the Female Who Laid Many Eggs

Eggs are usually laid on the underside of the leaf.	The day of hatching, the top of the egg turns black	Immediately after emerging, the monarch turns back and eats its own shell.

Challenge Question #14:
“If a single female monarch can lay hundreds and hundreds of eggs, why don’t we see hundreds and hundreds of monarch butterflies? What happens to them? List all the ideas you can imagine.”

(To respond to this question, please follow the instructions below.)

Challenge Question #15
Where’s The Next Mystery Monarch Habitat?
Here are photos and clues from another monarch habitat site:

“Luckily our Monarchs aren't here yet because our climate keeps changing from really hot to freezing and back again as it does most springs! Our tall, feathered, twice a year guests are here now spending most of their time along our main river, whose name in French means ‘flat.’ The closest thing we have to a mountain is the overpass on Interstate 80, but we do have hills made of sand in the western part of our state. We’re 1,549 miles (2,493 km) from the sanctuaries in Mexico. No milkweed yet, not even under the leaves in the flower bed.The maple trees are just starting the seed "helicopters. Tulips are blooming, and we've seen a few dandelions."

Challenge Question # 15:
"In what state or province do you think this monarch habitat is located? Send us your guess! (And, if you like, send a photo of your local monarch habitat, along with geographical clues, for a future Challenge Question.)"

(To respond to this question, please follow the instructions below.)

• Answers from the Monarch Expert

If you'd like to learn more about monarchs, check out Dr. Oberhauser's two websites:

• Monarchs in the Classroom for basic information on monarchs.
• The Monarch Larva Monitoring Project ( for information and research findings. Volunteers are needed!

IMPORTANT: Answer only ONE question in each e-mail message.

1. Address an e-mail message to: jn-challenge-monarch@learner.org
2. In the Subject Line of your message write: Challenge Question # 14 (or #15)
3. In the body of EACH message, give your answer to ONE of the questions above.

The Next Monarch Butterfly Migration Update Will Be Posted on April 11, 2003

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