FINAL Monarch Migration Update: November 3, 2000

Today's Report Includes:

La llegada: Students in Sanctuary Area Report Monarchs' Arrival
This was the week that waves of monarchs appeared in Angangueo. It's an a remarkable sight to see: Butterflies float through town, flying past windows and over rooftops, past donkeys carrying loads of wood, past men wearing the cowboy hats typical of this region, past chickens in people's yards and houses painted with vivid colors. Against this backdrop of Mexican life are the monarchs, so familiar in your own backyard, but now in an entirely different place. The atmosphere is lively and festive, and the butterflies decorate the sky as if for their own homecoming celebration.

"Las mariposas comenzaron a llegar ya por cantidades grandes," reported Escuela Jesus Salazar de San Cristobal. High in the mountains beside the Sierra Chincua sanctuary, Escuela Pedro Ascencio observed, "Por Garatachea han pasado pocas, pero la gente informa que en los santuarios ya hay muchas." You can read this week's comments below, but you'll notice that the students did not provide actual numbers. Apparently, the butterflies were seen in groups too large for them to count.

Thus, the long journey to Mexico is coming to a close. When Journey North begins next February, we'll have news from students and scientists in the sanctuary region, leading up to the butterflies' departure in March. (See note below.)

How Wide is the Finish Line? Discussion of Challenge Question #16
Last week, Dr. Calvert explained that to find the overwintering sites, monarchs flying in from the north must strike the Transvolcanic Belt somewhere within a 1.1 degree window. Challenge Question #16 asked, "Based on the measurements Dr. Calvert provides, how wide is the monarchs' finish line? Name a town that is the same distance from your town, so you can visualize this distance."

Using a map with longitude lines and a scale bar, you can see that at Angangueo's latitude, 1.1 degrees in longitude covers about 73 miles. The monarchs are aiming for a tiny target indeed! Imagine flying across eastern North America and finding such a small region. To visualize this distance, measure 73 miles from your home town and see where you land.

Now Flying Through the Mexican States of...Discussion of Challenge Question #15
We challenged you to find the towns Dr. Calvert named that are along the migration pathway in northern Mexico, and then name the state that each town is in. (Link to the detailed description of flight path.)

Were you able to find the towns listed below in these 7 Mexican states?

Nuevo Leon: Santa Catarina, Linares, Galeana
San Luis Potosi: Ciudad del Maiz, Cardenas, Rio Verde
Queretaro: Jalpan, Queretaro, Tequisquiapan
Guanajuato: Coroneo
Michoacan: Contepec, Mil Cumbres, Angangueo

It will take several more weeks for all migrating monarchs to reach the sanctuary region. In fact, people as far north as Vermont and New Jersey are still seeing monarchs! The peak migration is now still traveling through northern Mexico, and Senora Trevino reported thousands in Santa Catarina, Nuevo Leon last Sunday:

10/28/00 Santa Catarina NL (25.50 N, -100.40 W)

"El sabado 28 por la manana, fui a marcar mariposas a la finca El Ahuacatal que se localiza casi a la entrada del Canon de la Huasteca en Santa Catarina, Nuevo Leon, estuvimos algunos miembros del club de observadores de mariposas Papalotl deleitandonos con el magnifico espectaculo que ofrecieron miles de mariposas Monarca, perchadas en diferentes tipos de arboles, formando racimos tan densos que unicamente me habia tocado ver en los santuarios." (correal@mcsa.net.mx)

Where Do the Monarchs Go From Here? Discussion of Challenge Question #14
Think back to the questions raised by the monarchs reported in Florida in mid-October. Do you remember that the observer said the butterflies would cross the Gulf of Mexico on their way to the sanctuaries? Challenge Question #14 asked, "Do you think the monarchs sighted in these 3 regions of Florida are on their way to the sanctuaries in Mexico (19N, -100W)?"

We decided to ask Dr. Calvert for his expert opinion:

"The evidence and lack of evidence for monarchs crossing the Gulf of Mexico is considered below. There have been no tag recoveries that clearly indicate that they do cross the Gulf. But you'll have to read the evidence and make up your own mind about whether or not they do. I think you will find that weighing the evidence is what makes the process of science so exciting. This is how science works. It is seldom as certain as it is made out to be. The burden of determining what to believe is on you."

See You Next February When Journey North Begins!
Thanks to everyone for helping to track the monarch migration this fall. We hope you'll be back next spring to track the northward migration, as you welcome the butterflies' return to your home town. Watch for the first update from the monarch sanctuaries on Febraury 7, 2001.

This is the FINAL Monarch Butterfly Migration Update for Fall, 2000.