Tagging Monarchs

When do we tag monarchs in Madison?

  • As the length of the day 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 New England Aster and goldenrod are in bloom, the monarchs are migrating.

Peak Migration Dates for Madison, WI:

Lattitude Midpoint Peak in monarch abundance
    43 11 Sept         3-15 September

Guides for tagging monarchs: