Trailing the Karner Blue

Karner Blue © Ted Lee Eubanks

One of the special butterflies that can be found along the Discovery Trail is the Karner Blue, an endangered species limited in our area to the sandy soils that border Lake Michigan (such as Indiana Dunes National Lakeshore). This diminuative blue butterfly (about the size of a nickel) feeds only on the leaves of wild lupine, although it will take nectar from a number of flowering plants. Due to loss of habitat, the United States Fish and Wildlife Service listed the butterfly as endangered in 1992.

One of the factors that has influenced the loss of Karner Blue habitat, interestingly, is a lack of natural disturbance in the areas where wild lupine is native. This specialized habitat must be burned and/or grazed on a regular basis in order to limit the growth of woody plants. With urbanization fires are restricted, and therefore the pine and oak savannah/barrens that the butterfly and lupine prefer have disappeared.

Wild Lupine © Brenda Adams-Weyant

Combined with the loss of coastal habitat to development, conservation lands such as Indiana Dunes National Lakeshore (with a population estimated to be several thousand) and reintroduction programs by the Nature Conservancy will insure that this special neighbor continues to florish along our Beyond the Beach Discovery Trail.

Summer is the time when butterflies are abundant along the Discovery Trail. Now get out there and look!

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