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Monarch Butterfly Migration Update: October 3, 2003

Today’s Update Includes:

Highlights Along the Migration Trail

Click Map to Read Highlights Along the Migration Trail

After the passage of a strong cold front over the weekend, the winds shifted to the north and the butterflies set sail again. The monarchs’ daily progress is determined largely by the direction and strength of the winds, says Dr. Bill Calvert. Strong frontal systems tend to "bunch" them up into discreet pulses. Then, when the winds are northerly and strong, the monarchs fly far--perhaps as many as 400 miles in a day!

Here are some of this week's observations:

  • In Tarkio, Missouri, a student reported seeing 45 Monarch butterflies from her Grandpa's hospital window, flying overhead in a southerly direction during a fifteen minute observation time.
  • Just prior to sunset in Pilot Point, Texas, "approximately 400 Monarchs passed through our yard over a 1 hour period."
  • September 30 was a hot, sunny, nice day to play, said Sarah in Tyler, Texas. "I was playing with my little brother and he thought he saw a leaf but there were no trees around. I said, 'That is a Monarch.'"

First Clear Wave Moves Down the mid-Atlantic Coast
At last! After monitoring monarchs 3 times a day for the past 4 weeks, a strong migration was finally observed on Cape May, NJ. Dick Walton reported, "A cold front went through on Sunday and we had our first large push of monarchs into Cape May that afternoon and Monday." This year’s migration has been especially slow noted Walton, "the lowest numbers of monarch observed since beginning the census in 1991."

When Denise Gibbs, who's monitoring the migration about 150 miles down the coast on Assateague Island in Virginia, heard the news she said, "They’ll be here within 24 hours."

How can she predict with such precision? There are 3 long-term monarch migration monitoring sites on the Atlantic coast: Cape May, NJ, Assateague Island, VA, and Fisherman’s Island, VA. Monarchs don’t want to fly over the ocean, so the geography of the coastline funnels them through these places, making them great spots to monitor the migration. Based on past observations and tagging records there, monarchs have traveled from the Cape May monitoring site to Fisherman’s Island in just over 24 hours with good winds.

How Fast Do Monarchs Migrate?
As monarchs pass over your head on their way to Mexico you probably wonder--where will those butterflies be in a few hours, days, or weeks? How fast do monarchs migrate? Nobody knows for sure, but these monarchs that were tagged and recaptured on the Atlantic Coast tell some tales:

Hurricanes and Flowers: Did You Predict the Connection?
By Elizabeth Howard
Notice the dead, brown needles on the east side of the pines while those on the west side remain green.

When considering how Hurricane Isabel might affect monarch migration, did you think about salt damage? I didn't, and so I was amazed to see what had happened to the flowers and other vegetation when I visited Denise Gibbs on the Virginia Coast over the weekend.

When the hurricane came ashore the winds were loaded with salt from the ocean. Salt spray coated the plants so heavily that flowers and leaves died back within 24 hours. The effect won't be permanent, but monarchs migrating down the coast won't find the nectar sources that typically await them. The landscape looked as it would after a heavy frost. The hurricane arrived from the east, so plants exposed on the east were burned by the salt. Miles and miles of coastline were thus affected. The leaves and flowers of seaside goldenrod, a favored plant during migration, were completely brown.

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"When the monarchs get to Assateague Island they're here to fuel up. I’ve tagged them and watched them stay on the same plants for 5 days, just nectaring. This year there are still some flowers in scattered places that were protected from the hurricane. But on the most part, this is what it looks like," said Denise pointing at the dead vegetation up the shoreline. "This is all the nectar they're going to have."

Challenge Question #9:
"Adult monarch butterflies eat nectar, but it’s especially important to them in the fall. Explain why."

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

Salt Damage from Hurricane Isabel

Denise Gibbs shows Dr. Lincoln Brower how coastal plants were damaged by the hurricane. HuricaneIsabel05

Noticias del avance de la migración en México
From south of the border, monarchs were reported in the Mexican states of Coahuila, Nuevo León and also the state of Sonora. Rocío Treviño, whose education program tracks the migration there, said the Sonora sightings raised some interesting questions for her:
  • ?Estas mariposas son parte de las mariposas que hibernan en California USA?
  • ?Algunas mariposas del oeste hibernan en Michoacán y viajan por la costa del Pacífico?

Speak Spanish? Discussion of Challenge Question #7
Last week we asked, "Can you translate the message from the Mexican state of Coahuila? How many monarchs per hour did the observer count?"

Thanks to the 8th grade Spanish 2 class at Anchorage School, in Louisville, Kentucky for coming forward with:

The translation: "The first Monarchs are beginning to arrive in Mexico. After three days of rain and clouds, the sun came out and I saw 4 Monarchs in 2 hours."

And the math: "Since he saw 4 Monarchs in 2 hours, an easy math conclusion to find the average could be that he saw 2 butterflies in each hour."

Watching and Waiting at the Mexican Sanctuaries

Can you find the monarch sanctuary nearest to each school?

Empty skies, say the students who are waiting beside the sanctuaries in Michoacan, Mexico. Like spectators at the finish line of a long marathon, the students are watching the skies daily, waiting for the monarchs to arrive. Once again this week, there were scattered observations of a few monarch butterflies. How do you interpret these? Discuss with your class, then compare Dr. Bill Calvert's thoughts with your own.
October Conservation Perspectives: A View from Mexico
Jordi Honey-Rosés
In this month’s update, Jordi Honey Rosés discusses:

Ecotourism: The Monarch Expo, an educational exhibit and fair planned for November. The Expo includes a clever plan to encourage ecotourism a bike ride through a rarely visited sanctuary region where communities, while part of the Protected Area since 1986, have never benefited from tourism.

Sanctuary Management: Fire-prevention training takes place this week at the monarch reserve.

Political Changes: President Fox abruptly fired Environmental Ministers in September, and Jordi speculates why.

Symbolic Migration Deadline Oct 14: Please Support Monarch Conservation
Only 11 more butterfly-making days before the Symbolic Migration deadline. Don't be late! Butterflies received after the postmarked deadline cannot migrate.

The forest sanctuaries in Mexico are not adequately protected. Logging and other development threaten the habitat monarchs need to survive the winter. Please send support for the real butterflies with your symbolic monarchs:

Discussion of CQ #8: Energy Costs of Flapping Flight
Last week we took a closer look at flapping flight to see why it burns so much energy. We asked, "If a monarch flaps its wings 5 to 12 times per second, how many times per minute does it flap? How many times can you flap your arms in a minute?"

Mrs. Swentzel’s third grade class in Stanhope, NJ, figured a monarch would flap from 300 to 720 times a minute.

"We then tried flapping our own arms for a minute and found that we could only flap from 48-115 times in one minute. My students were amazed and could not believe that these tiny creatures were able to do what they must do in order to make it down to Mexico. Now they understand why it is so important that the monarchs catch those thermals and north winds to help speed them on their way."

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Links to Video Clip and Still Images

How to Respond to Today's Challenge Question
1. Address an e-mail message to:
2. In the Subject Line of the message write: Challenge Question #9
3. In the body of the message, answer the question above.

The Next Monarch Migration Update Will Be Posted on October 10, 2003.

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