From www.monarchwatch.org:
Many questions remain unanswered about the fall migration of the monarch population east of the Rocky Mountains. How do the monarchs move across the continent, i.e. do they move in specific directions or take certain pathways? How is the migration influenced by the weather and are there differences in the migration from year to year? We need data to answer these questions and we need your help! Only through the cooperative efforts of volunteer taggers will we be able to obtain sufficient recoveries and observations of the migration to answer these questions. Because monarchs have a certain “charisma” and a fascinating biology and because its fun to have an excuse to collect butterflies, this project is also a good way to introduce students to science and have them contribute to a scientific study. Through participation in this project we also hope to further interest in the conservation of habitats critical to the survival of the monarch butterfly and its magnificent migrations.
When do you tag Monarchs?
As the length of daylight shortens in mid August and September, monarchs in northern latitudes, i.e. near the Canadian border, begin to migrate. Monarchs farther south will begin their journey a few weeks later. Tagging and monitoring should begin in late August in all regions, with a concentrated effort made in September and early October. A GOOD RULE: when the wild asters, especially A. novae-angliae, goldenrod and Joe Pye weed are in bloom, the monarchs are migrating. In much of the lower midwest, migrating monarchs are attracted in large numbers to a tall late blooming thistle (Cirsium altissimum) several species of sunflowers and other species of Asteraceae.
Additionally, you can determine the estimated peak of the migration in your area based on latitude:
Peak Migration Dates
The peak of this year’s Monarch migration will travel through Oklahoma the last week of September. Tags are going fast but are still available – they will typically arrive within 7-10 days of placing an order online or by phone. Monarch Watch Tagging Kits and other materials (don’t forget to pick up a butterfly net!) are available via the Monarch Watch Shop online at
http://shop.monarchwatch.org/category.aspx?c=tagging_kits or by phone at 1-800-780-9986
Happy Tagging!