Another butterfly, smaller than the Monarch but mimicking its color pattern, can be found in areas inhabited by the Monarch. Compare the left photo of the Monarch to the right photo of its mimic. This mimic, called a Viceroy (Limenitis archippus), does not feed on milkweed and is not toxic. It would be acceptable food for a bird, but if the bird has already learned not to eat a Monarch, the bird will leave the Viceroy alone as well. If a bird ate a Viceroy first, it might not learn that the color pattern is meant to be a warning. That would make the mimicry less effective, so there are fewer Viceroys than Monarchs. Lower numbers of Viceroys increase the chances that the first contact a bird has would be with a Monarch. As fall approaches, some individual Monarchs begin a migration. The most famous migration takes the butterflies to Mexico, but eastern populations also overwinter in Florida and along the coast of Texas. The migration period extends from about August through October. A project in which migrating Monarchs are tagged and followed in Arkansas is described at www.uamont.edu/FacultyWeb/Edson/MonarchArkansasWatch.htm.