"Teachable Moment"
Monarch Butterfly Migration
story and photographs by members of the Biology classes

A Monarch Migration
by Amber Hawthorne


      We were given some caterpillars from UAM that would eventually become Monarch Butterflies. After filling up on leaves of the milkweed plant, the caterpillars crawled to the top of the box to make a silken pad to attach themselves. After attachment, they hang down in a prepupal "J" position before shedding their skin for the last time. After hanging for a few hours, the caterpillars shed their skin to complete the transformation into a chrysalis. It took only a few seconds for the skin to drop off.

      That was almost a month ago. Today, we actually have the chance to see the Monarchs leaving their cocoons. It was really neat. No one in our class had ever seen this stage. Right after the butterflies emerged, their wings were wet and wrinkled, but in about five or ten minutes, they had straightened out. However, they were still not fully dried. The drying process takes thirty days.

      All of the biology classes are having to do an insect collection. If we catch Monarch Butterflies while insect hunting, we bring them to school alive and receive one point for each butterfly we bring in addition to the dead one for our collections. We bring the Monarchs on so we can tag them and them let them go. The purpose of tagging them is to follow their migration patterns. Since 1937, scientists have been trying to find out to where the Monarchs migrated. Fred A. Urquhart was the man that found out just that. One of the major problems was finding a way to tag the butterflies. The first tags were glued to the wings with liquid glue, but only made the Monarchs sticky and left many unable to fly. Next, butterflies were tagged with gumstock, like stamps. This allowed the butterflies to fly, but washed off when wet. Finally, a foolproof tag came about. It contains pressure adhesive like the price tags on glass. All one has to do is gently squeeze the tag on the membrane of the wing that has no cells. Not even water removes the tags.

      Mr. Urquhart started a volunteer program to help with the tagging. A group that started out as twelve, mutiplied to six hundred by 1971. The tags had numbers and letters with the words: "send to Zoology University, Toronto, Canada." Many Monarchs were returned to the university. Still, the scientists did not know where the butterflies spent their winters. All they knew was where the butterflies took off from; all over the northern part of the U.S. and the southern part of Canada. Several things were learned. One was that most males die on their way north after migration. Another was that Monarchs do not fly at night. Also that most migrating Monarchs hatch late in the summer, and the females do not sexually mature until migration is over. It is then that they mate. A man by the name of Ken Brugger went to Mexico to investigate reports of large clusters of butterflies in the area. He found a colony of more than a million Monarchs in evergreens beside a mountain clearing. The butterflies covered tree branches and the ground, and one tree limb even broke off the tree. Even though the limb was not very big, a monarch is extremely light. Think of how many Monarchs must have been on it! Consequently, there was actually a tagged butterfly found in the millions. It had come all the way from Chaska, Minnesota. The temperature of the Monarch's overwintering place, Mexico's Sierra Madre, ranges from just below freezing to just above in winter, ideal for the butterflies.

Caterpillar in a prepupal "J" (center), and a chrysalis (left).



Emerging Butterfly





New Butterflies "born" in our classroom



Monarch butterflies captured for tagging and releasing





Releasing tagged butterflies