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Monarch Butterfly Migration Update: March 14, 2002

Today's Report Includes:

Adios Angangueo
Dave Kust to Head North With the Monarchs

March 13, 2002

One week left! It is very sad.....Major monarch traffic overhead the last three days. We have been watching from the courtyard of our home. Today seems to be the heaviest flow with 27/minute at 11 am , then 48 per minute at 11:15am and then 120 per minute through my binocular lenses at11:45 am. They are flying high and low...With many stopping to nectar in the tree blossom of our neighbors courtyard. The butterflies in all three colonies I have visited last week all are moving gradually down from their roosts. Major streaming at Pelon...saw the most activity there yesterday. I believe the Zapetero colony will exit through Senguio (Chincua)....Prince Charles got to see them just in time! Rosario is also very strung out and moving down. The upper colony is moving more laterally and may take a different exit as well. Sunny at warm here all week. Nice south breezes flowing through. Just outside Claudia's internet cafe here I can see the monarchs flowing by the cathedral??

After Chip Taylor from Monarch Watch stayed with us, he returned home and posted a nice story and several pictures on the web. If you are interested you can find that at:

Hasta luego,
Dave Kust

Monarch Watch Tag Recovery Fund: You Can Help

Due to the January storm, an unprecedented number of monarch tags have been recovered in Mexico. Monarch Watch pays the local people 50 pesos per tag found. In past years, the most tags ever recovered in a single year was 689. This year a total of 1,772 tag have already been found and paid for, which will cost $9,844. Thus far, they have raised $6,664.63 to over these costs, so another $3179 is needed.

Please consider a donation to Monarch Watch to help this fund. You?ll not only support the Monarch Watch tagging program, but will also provide needed income for the people in the sanctuary area.

Final Field Notes From Mexico by Dr. Bill Calvert
Final Field Notes from Mexico by Dr. Bill Calvert

March 7, 2002

We had heard about the new colony of monarchs the week before and decided to visit. It was one of the ?staging colonies? on the northwest face of the Cerro Pelon massif. A staging colony is one where butterflies accumulate in preparation for their flight north. The monarchs had spent the bulk of the winter higher up the mountain slopes, or possibly on the south side above the communities of Macheros and Capulines. Our bus coughed up the dusty road. Rumor was that the road was being paved for Prince Charles? visit, which is to take place on Friday, March 8.

British Monarch Visits the Monarchs
According to Prince Charles? official Website, the Monarchs were named by British settlers after the Prince's ancestor, William of Orange.

We saw butterflies as far down as Nicolas Romero and knew that we were in for a treat. At El Campimento we left our bus and started upward, following the arroyo. The arroyo was ?Las Canoes? named for the wooden watering troughs higher up in its headwaters.

Butterflies poured down the arroyo and across adjoining fields by the thousands--it was some sight, let me tell you. At times they enveloped the stately agave (century plants) that mark the boundaries of the fields. As the arroyo narrowed the butterfly stream concentrated until there was a flowing river of orange and black filling the arroyo to a depth of 3 meters and entirely in our faces. They were beautiful.

The forest through with the arroyo ran was depauperate. Only a few wolf trees (lone trees) remain. These were festooned with butterfly clusters. As far upward as we could see there was no intact forest in sight.

Also in the arroyo and accompanying our group were four little girls, ages 10-12. They had been instructed by our guide, their grandfather, to stay with gringo stragglers to make sure they did not get lost. Mainly they were curious about us and giggled a lot. One couldn?t help but wonder about their futures. Their fathers had cut the forest that belongs to the community. They had spent their capital. Not much revenue could be got from those forest remnants for at least 20 years, and the supply of water itself was in jeopardy.

March 12, 2002

This week I?m with a group of teachers from schools in New Jersey, North Carolina, Georgia and Texas. On Sunday, March 10 we visited the base of the mountain on which the Piedra Herrada colony is located. On Monday we visited El Rosario. Both days were partly cloudy and therefore cool. Nonetheless, at Piedra Herrada we were greeted and deluged with butterflies that had poured off the mountain to fill the road, the arroyos, and to grace the watering holes. Our birder contingent managed to scare up a Mountain Trogan and a Flame-colored Tanager.

At El Rosario it was cooler. Instead of filling fields and forests along the road from Angangueo, as would be expected this time of year, the butterflies were confined to the immediate area of the colony. Pulses of sun and clouds made the viewing most interesting. When clouds came the tempo of flight activity increased noticeably, only to die back as the butterflies rejoined their clusters when clouds persisted or return to basking if the sun returned. This phenomena--sudden pulses of flight when a cloud covers the sun--is known as ?the could effect.?

Witnessing a Predator Feeding Frenzy
At El Rosario we were treated to a predator feeding frenzy that was just amazing. Two brilliant male Black-backed Orioles and two Black-headed Grosbeaks landed on a tree in full view of our observation point. They preceded to take monarchs from the clusters and eat them. They held the butterflies down with one foot and tore off the wings before consuming body parts. We tried hard to observe any ?unzipping? of butterfly abdomens, as orioles are known to do, but were too far away to see it. The birds remained in view for at least 10 minutes and consumed an estimated 20 butterflies. These processes repeated over and over. It was mid-afternoon, and we watched until we were forced to leave. Imagine--these butterflies had survived the entire over-wintering seasonincluding the strongest storm in recorded history--only to be eaten on March 11. They almost made it.

We haven?t witnessed any mass exits. It?s still been cold and they?re not doing much. I think their departure is probably ?stop and go.? They leave when it warms up and stop when it?s cool. At the end of the week we will all go home. All and all, it has been a most interesting and notable year.

Bill Calvert

Millions of Monarchs Eaten By Predators
To a predator, monarchs clustered by the millions can be a rich source of food and easy prey. For predators who can handle the poisons in the monarchs, that is. When they are caterpillars, monarchs eat milkweeds that contain toxins called "cardenolides." This poison is stored in the adult monarch's abdomen. Because it is poisonous to vertebrates, the toxin is a form of defense for the monarch. Of all the possible predators in the sanctuary area, only 3 vertebrates prey extensively on monarchs--one mouse species and two bird species. In a typical year, upwards of 15% of the entire over-wintering population dies due to predatory activities. When the monarchs arrive in November, not a single butterfly wing is on the ground. By March, the forest floor is peppered with dead butterflies.

Close inspection of a dead butterfly gives a clue as to its predator:
Predator Clue
Black-headed Grosbeak The monarch's abdomen is entirely missing.
Black-backed Oriole The monarch's abdomen is present, but it appears to be "unzipped" (slit open) and the thorax is gorged.
Black-eared Mouse Caches of butterflies are found on the ground, and only the wings remain.

Who Ate These Butterflies?

Challenge Question #11
Inspect these butterflies carefully and see if you can determine who the predators were: (Click on photos to enlarge.)




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

Impressions from a Visiting New Jersey Teacher
By Maureen Barrett, Harrington Middle School
Mount Laurel, New Jersey

?I couldn?t ascend the 1,500 feet fast enough in anticipation of what I would find. I had read about the monarchs clustering in the oyamel forest in Mexico for years and was about to witness this magnificent sight for myself. And what a magnificent sight it was! There were thousands of monarchs in flight and millions more clustered in the oyamel fir trees. The weight of the butterfly clusters bowed the branches, making the clusters look like huge hornets? nests hanging in the fir trees. For a few hours I marveled over each and every butterfly, over each and every cluster, unable to take in enough of this beauty.

?It was extremely difficult leaving the El Rosario colony that day. I had just witnessed one of nature?s miracles, something truly spectacular, something truly amazing, something I will never forget.?
Maureen Barrett
Harrington Middle School
Mount Laurel, New Jersey

Regresan las mariposas!
First Report From Migration Pathway in Mexico

The monarchs are on their way! This report just in, from the state of Queretaro, 138 miles (222 km) north of the overwintering sites:

?Los dias 8 y 9 de marzo, Julio Carrera (padre e hijo) y Elsa Zamarron estuvieron haciendo un conteo de venados en la Sierra Gorda y observaron 15 mariposas por dia en el ejido La Tinaja, San Juan de Buenaventura y Ahuacatlan en el municipio de Arroyo Seco, Queretaro. Ellos comentaron que a pesar de tener el viento soplando hacia el sur, las mariposas volaban siempre al norte. Son las primeras noticias del regreso de las mariposas, seguire enviando informacion.?
Contributed by Senora Rocio Trevino, Correo Real

Translations Please! Challenge Question #12
What does this say and what does it tell us about monarch migration?

Challenge Question #12
?Ellos comentaron que a pesar de tener el viento soplando hacia el sur, las mariposas volaban siempre al norte.?

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

Migratory Monarchs in Texas?
First Migration Map of Spring, 2002

?They may not be from the sanctuaries, but I did see two monarchs power-stroking from southwest to northeast,? wrote Harlen Ashen from Port Lavaca, TX, on Tuesday. As today?s map shows, two other monarchs were report in Texas, from San Antonio and Houston.

There?s always uncertainty each spring when monarchs are sighted in places they?ve been spotted during the winter. It?s about a 500 mile trip from the sanctuaries to the southern tip of Texas. We?ll know more next week as more monarchs start flooding across the border.

** Please Report Your Winter Monarch Sightings NOW! ***

A Careful Look at Monarch Wings
Discussion of Challenge Question #10



We asked, "How does the resting position of a monarch help to camouflage the butterfly in the oyamel forest? In your answer, include the names of the wing surfaces that are important for camouflage."

First graders in Ferrisburgh, VT noted carefully: ?When it is resting, the butterfly folds its wings, so that the hindwing is covering the forewing. That makes the butterfly smaller and harder to see. The underside of the wing is gray like a piece of bark. The top side is bright orange. The butterfly looks like a piece of bark until it opens its wings. When they are flying or eating, they look like flowers because their wings are so bright and pretty.?

The undersides of Monarch wings.

Resting Monarchs with folded wings.

Can you see the dull tips of the forewings?

What great observers! Inspect the photo on the left carefully. You are seeing only the undersides of the wings. Look how brightly colored most of the underside of the forewing is. However, did you notice that the tip of the forewing is dull? Now look at the photo on the right. When monarchs fold their wings, they cover most of the forewings. Only the dull tips of the undersides of the forewings show.

How to Respond to Today's Challenge Questions:

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

1.Address an e-mail message to:
2. In the Subject Line of your message write: Challenge Question # 11 (or #12).
3. In the body of EACH message, give your answer to ONE of the questions above.

The Next Monarch Migration Update Will Be Posted on March 21, 2002

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