This butterfly is a common visitor to the butterfly garden appearing in July and becoming more common during August and September. The wings of the butterfly on the left are spread to collect the sun's heat. This type of behavior is known as basking and can be observed early or late in the day. The monarch on the right is sipping nectar from liatris. Monarchs can be seen visiting several species of milkweed, Queen Anne's lace, liatris, ironweed, goldenrod and other late blooming species. Their host plant is milkweed. By carefully examining these plants you may be able to find the eggs, larvae or chrysalis of a monarch. Milkweeds contain cardiac glycosides as well as a substance that makes birds vomit. It is thought the bright colors of the larvae and adults serve as warnings to birds. Once a bird has sampled a monarch it gets sick and learns to avoid them in the future. The color pattern of the Viceroy mimics that of the monarch. If birds have difficulty distinguishing between the two, then in areas where both occur together the viceroy should be less apt to be attacked by birds. Originally it was thought that the viceroy was palatable, but recent data suggest that like the monarch the viceroy is also distasteful. For this reason they are considered co-mimics.
Monarchs are also known to migrate. In the summer they fly north to lay their eggs and in the fall they fly south to Florida or Mexico to overwinter. At least one butterfly tagged in Ohio has been recovered in Mexico. Once in Mexico the butterflies become inactive. As their fat stores are used up they become sexually mature, mate and fly north. It is unlikely any of these make it as far as Ohio. They lay their eggs in southern states. The larvae that hatch from these eggs mature and continue the northward migration. Some of these reach Ohio and the cycle continues.