The Monarch butterfly (Danaus plexippus) is perhaps the easiest butterfly to attract to a garden. Milkweeds (Asclepias species) are the hosts for the caterpillars and if planted in the garden, Monarchs will find them. Milkweeds produce cardioactive glycosides as a defense against most herbivores; caterpillars in the Danaidae (milkweed butterfly family) sequester the glycosides.

Birds and other predators quickly learn that Monarchs not only taste bad, they upset the stomach. I once observed a young northern shrike eat a Monarch. The bird attempted to land on a fence, but became disoriented, fell to the ground, shook its head, and vomited. After about 10 or 15 minutes, the shrike regained its senses and flew away.

In Florida, there are three butterflies which mimic each other--the Monarch and the Queen (Danaus gilippus) which feed on milkweeds, and the Viceroy (Limenitis archippus) which feeds on willows (Salix species). The three species are an example of Mullerian mimicry, the aposematic (warning) coloration and the fact that all taste bad, reinforces protection from predators.

According to Thomas C. Emmel, Monarchs in Florida have two migration routes to Mexico. The butterflies either fly along the Gulf coast to Texas and Mexico or they go south, then across the Gulf of Mexico. They have been known to take rest stops on drilling platforms in the Gulf. (Florida's Fabulous Butterflies, World Publications, 1999) In my experience, a few Monarchs linger through the winter and will fly on warm days.

These caterpillars were photographed in late March. They are feeding on scarlet milkweed (Asclepias curassavica Linnaeus), a species native to tropical America. Scarlet milkweed does not die-back unless the winter weather is severe and may well be the reason that a few Monarchs remain in my garden through the winter months.